As a veteran of many an HT forum, I've been reading posts recommending SPF meters for quite a while. I realized they were probably helpful but put off buying one until yesterday.

WOW!! The difference on my 950 was as dramatic as going from mono to stereo if not more so.

I always trusted my ear and had big problems conceptually setting up matched speakers to different levels - but I tried it anyway since I already invested the $39.95 at RatShack.

The sound went from decent to incredible at a single stroke.

The reason I'm bothering to write this is that posts I've read before stress the importance of metering your speakers. But maybe they weren't emphatic enough for my thick skull.

Put simply, if you haven't metered your speakers yet no matter how good your ear - you're not hearing close to what your system's capable of. That goes for the 950, and I'm sure all other multichannel systems.

If you haven't already, just do it and expect to be impressed!

Hear hear, I definitely noticed a sound difference when I did this.

------------------
Matthew J. Hill
matt@idsi.net

After assuming, I needed to be in the mood, to figure it all out and putting it off for several reasons. I was gently chided to do this myself, (Thanks guys ).
I figured out the meter all by my lonesome, it was so much easier than I expected it to be.
And the difference this simple step makes is astounding. The best part is, now I know the benifits and can easily keep things in shape as often as needed in future.
Agreed: its a very high return for under 50 dollars.

So, could either of you post a short step-by-step procedure you are using to calibrate your speakers? I am still waiting for my 950 to arrive :-(. Just getting geared up for that auspicious day.

There is a procedure in the manual that is pretty much what you ask for. I think you can still take it down in the product section.

I feel your pain I am in your same position! Everyone here is very helpful. I recently purchased the Avia Home Theater DVD disc. Maybe this link will be helpful: http://www.ovationsw.com/
Good Luck and hang in there!
DMC

YOu could also sink another $5.00 into a small flashlight with a "flat" butt. I use a small hand held flashlight and put it flush on the baffle of my speakers (right above the tweeter) and then I zero them into my listening position. This realy helped when I moved my center channel underneath my tv, and needed to focus the sound to the listening position. Some people use lasers, but I fugure that the sound waves have a tendency to spread out so the "wide beam" of the flashlight probibaly works just as well. Just make certain that you have a person sitting in the target area when you tweak the surrounds and center. (I found that crossing the surrounds about a foot behind the listener gives me the best sound...but to each their own.)

Jason

I'd also recommend $20 or so for a tripod to put the SPL meter on. Gets it away from your body, which can interfere with the measurements due to bouncing waves and such.

Sorry, not very 'short' jimr but here goes.
(And if I did it wrong, they'll let us know...it was my first. )
I picked up a Radio Shack Sound Lever Meter, the cheaper one (aprox. 40). The other model was ummm Digital? The Outlaw Owner’s Manuel, (thank you Outlaw!) does walk you right through it on pg. 27.
Outlaw recommends calibrating to 75db/SPL

Turn you 950 & ? amp on with NO source playing.
Set main volume control on the 950 to 0dB

Sit in your central listening position holding the meter at ear height.
Outlaw states: point the meter at ear level towards your CEILING.
The instructions that come with my meter say point the meter AT the speaker.
I used Outlaws recommendation and pointed to the ceiling.

Set your meter to Slow response and ‘C” weighting.
Set range on your meter to 70 (and work up)
Or 80 (and work down)
(You set your meter using the big black scroll button on the meter marked: Range.)

I won’t walk the menus on the 950 (it will be in your manual)
But access Channel Calib Menu, which looks like
> Left Front: 0db
Center Front: 0db
Etc.
As you use your remote to scroll the > onto each choice press select for each speaker in turn, you will hear the fairly loud test tone through the speaker selected.
Your meter needle will jump to ‘something’.
Use the < > (after hitting select first on your 950 remote) to move your volume up or down for that particular speaker till the sound meter needle swings to 0.
If you have selected 70 range on your meter 0 = 70.
If you have selected 80 range on your meter 0 = 80.
Work up or down depending on your starting choice till the needle registers: 75dB.

I thought the trim feature on the 950 was separate from the Channel Calb, entirely, to be used to tweak something temporally whilst still keeping Calb set at its original specs. I noticed after calibrating Trim dB’s = what you set in Channel Calb.
One thing I ran into is something the guys here could prob. answer. I got a test tone for the subwoofer (so I assumed I should calibrate it also) but this caused my needle to peg right; even when I adjusted the SW volume to its lowest setting –15dB.
Puzzled I tried setting my meter to “A” weighting, then I could get the needle to swing to 0 using volume controls. This still gave me a little too much LF on some viewing, so I went back and lowered the dB on it the next day.

Is ‘A’ weighting normally used for the SW, the meter or Outlaw manuals did not explain; or did I mishandle this portion?

I was wondering about that myself. The Radio Shack guy told me to use the A and Slow settings. And of course everything sounded fine until the subwoofer which even though had the neighbors peering out windows didn't register until I switched to the C setting.

Since I spend a lot of time manually adjusting levels on the sub anyway between movies and music I didn't worry about it. And the improvements were major. But I would also like to know whether to use A or C or both for best results.

I would like to add a recommendation here. I set my trusty Radio Schmuck meter (analog version) on boxes or something similar on the chair in my prime listening position, and get the microphone as close as I can to the position where my head would be. I then get myself off to the side of the room somewhere where I'm not in the direct line of fire of any speaker to the meter, and accoustically I should be "out of the way", but where I can easily see the meter. I then run the test tones (with the remote, of course) and adjust from there. I have found this method to be more accurate than holding the meter while sitting in the chair. I have had a meter for quite a while, and have found it to be well worth the investment. The first time I used it I discovered that previously by ear I had all of my speakers balanced within 1 dB, except the rears were 1 dB louder than what the meter liked. I assumed this was because the meter is truely omnidirectional, and our ears are not. Our ears are pointed forward. So when I balanced by ear, I had set the rear speakers 1 dB louder to compensate for that fact. I decided than since I usually listen with my ears instead of the meter, I would leave the rear speakers set 1 dB louder. I have since run some tests with some friends of mine, and have discovered that indeed most of them cannot balance speakers by ear nearly as accurately as by using a meter. Why I can I am not sure, my hearing is just unususally good in some respects, but it's still nice to have the meter for verification. I actually checked one system where when the owners set it up by ear they had the center channel 8dB too low and the surrounds 10dB too high. Needless to say, after readjusting, they were amazed.

That Rat Schack meter is not as efficient at subwoofer frequencies, and therefore registers a lower meter reading than what the sub is actually putting out. SV Subs has a chart showing the offsets at
various frequencies, and proper sub calibration procedures:

http://www.svsubwoofers.com/faq.htm#meter

This is a mistake you hopefully only make once... (Bit me on my pre-950 setup)

Make double sure that none of your sources are active while you're performing calibration. If you were to mistakenly switch to one of them you'd go from relative quiet to full reference in a split second. This is guaranteed to wake you up, and could possibly damage your speakers...

Carlos

HTcrazed,
It sounded like you were asking...
I've only ever heard that "C" weighting and "Slow" modes be used for home theater speaker calibration.
The "Slow" so that you can read the response, or determine the average (as you sometimes have to do with a subwoofer). The "C" I'm not sure about, but it's the only setting I've seen be recommended.

also use an outside source for taking these measurments,

Avia,VE or Sound and Visions Tune Up,

the sound coming from your dvd player will be different then just using the tones in your preamp....

C and A weighting apply different values to different octaves. Can't remember for sure which is which, but one is based upon equal sound energy in each octave, the other is based upon the 'normal' human hearing curve. The slow response just keeps the meter from bouncing around too much, giving more of an average reading.

I did this once. I think I was lucky I didn't blow any drivers...

I read a THX document once that said you're supposed to point the mike straight up, and I've always done it that way since. Makes it easier because you don't have to change the position of the meter when measuring the surrounds, for example. Don't know if it makes a difference or not.



This is why when *anybody* says they can hear "etched highs", a "detailed midrange," and a "tight but robust low end," I don't put much stock in it. Human's hearing just isn't that great. And "auditory memory" is even worse. I want to see measurements darn it! Easier to compare components that way. Source components and pre/pros-receivers. Speakers are way different of course (interactions with the room, etc).


[This message has been edited by Kevin C Brown (edited August 02, 2002).]

Hmmm..
Kevin, I don't think a system's speaker levels would relate to your comments about etched highs or midrange.
That's usually releated to speaker's overall freq. response and associated equiptment sound quality -regardless of matching or unmatched surround levels.
I agree w/ the bass range though 'cuz then you can be talking about a sub's level being poorly leveled w/ the mains.

And I don't know Kevin... Human ears ain't that good? Specs are better?
I gotta disagree.

Most solid state amps all rate pretty much close to zero % dist. at normal list. levels, yet they do not all sound the same at this level to human ears. Are the lab tests wrong?

No, we just didn't also measure (probably many) other factors that our ears can easily hear when we switch one component for another.

Unlike our crappy human eyes that are easily duped into thinking we're seeing motion by still images switched as low as ~20 frames a sec. most (probably all of us) can tell very tiny changes in audio waves processed @ tens of thousands of times a second.

It may be possible to measure all of our equip. more accurately than our ears can hear, but these tests either don't all exist yet, and/or just aren't being done -hence the need for lots of human opinion reviews in add. to lab tests.

I really wish the human factor could be taken out of the equation, but it can't yet.
If it could then we'd be able to say the Outlaw 950 is just as good as pre/pro X and the long debates wouldn't be needed. We could just state specs and point to the winner.

This SLP meter thread's a great example.

The idea of perfectly setting all your speakers to the exactly same volume is a great idea, but 'real world' you see here all the probs that crop up in trying to do so...

The analog Rat Shack meter (prefered over the digital by everyone) is very inaccurate and needs correction after you (additionally inaccurately) read the meter.

Then do you point the meter up so it's more omnidirectional (though it's still not totally), or do you point it forward closer mimicing how are ears are 'aimed' forward?
Some say one way. Some say the other.
'A' or 'C' weighted?

Which brings us to the fact that identical main speakers placed behind you will sound different because of how your ears are shaped (muffling the high end in simplistic terms) so matching their volume isn't ever going to be totally accurate anyway.

Then you just calibrated w/ your pre/pro's test tones, BUT when you play a test DVD like V.E. or Avia, etc., you find it's calibrated differently, so you have to choose which to calibrate to 'cuz they both can't be 'right'.

And then you have the fact that after you do your very very very best you can to minimize all these inherent flaws in the calibration method, you have to contend with assorted DVD soundtracks that have diff. surround, sub levels anyway screwing up your effort far more than any previous variable.
And these DVD/CD's are what you calibrated you system for in the first place!
Almost a cruel joke it seems.

I can play one DVD and feel the rears are too loud. Play another and their too quiet. I'm sure others have found this to be the case also.
Some might say -'Well at least you know you're hearing it the way it was meant it to sound', but I'd bet that's not really the case.

And let's say 'system x' is calibrated 'perefectly' to 75 or 80db being -0.-most people still choose to lower the volume from this 'ref. level' altering the entire calibrated system anyway.
Do you ever tap the volume during a flick? I know I ain't the only one who can't put the damn remote down and just watch the freakin' movie! -heh

All these factors have stopped me from getting an SLP meter myself and calibrating my system to an assortment of these personally chosen variables.

Instead I listen to reference point tracks of several DVDs and CDs and adjust the surrounds and my dual subs so they sound well blended in on all these varied reference points.

Highly accurate? No, but not any less accurate that the current 'technical' method.

Just a thought I wanted to throw out there.
(i like to play w/ matches. let the flames begin -heh)

[This message has been edited by azryan (edited August 04, 2002).]

I don't think the value of an SPF meter is that human hearing isn't very good. If it weren't, how would we hear better results by using one?

I think it has most to do with the different speakers sizes and types used in a 5.1 plus setting and most of us not knowing what a multichannel setup should actually sound like.

For example, like most I'm using towers for mains, bookshelfs for surrounds and something larger than bookshelf for center. Though they're all B&W, they sound different when the tone's going through and its harder to compare fine gradiations in loudness to sounds of differing frequencies.

Also, even though I did hear my left main was louder than the right, I never would have dreamed of setting them to different levels (a leftover old wives tail from 2 channel days). And the default of the 950 makes the voice tracks easy to hear by having the center louder, but it turns out to noticeably degrade the overall soundstage unless you set it even to the other speakers (which I think resulted in a center speaker setting of -6 in my system).

I don't think the problem is with human hearing ability, more with our not being familiar enough yet with what a multichannel system is actually supposed to sound like when optimally setup. Which is why the SPF meter works so impressively.

Judgements about how revealing the mids, etched the highs, bloomy the bass, size of the soundstage, has nothing to do with comparing volume levels. And if we weren't capable of discriminating these sounds, non of us would ever need to consider the extra cost and fewer creature comforts of seperates in the first place.

It's ok you are satisfied with your calibration methods,azryan, but for the rest of us (vast majority) using the meter is a much better way to go. After all, most, if not all manufacturers recommend using a meter for best results. Why does the meter give the best results? Probably has something to do with that thing found between our ears. I think you need to establish a good base to work from and the meter will give you that. Once you do this- go ahead and tweak the settings based on the material you're listening to- IF you feel it's necessary. A properly calibrated system should reproduce the soundtrack as it was intended for you to hear it- with the appropriate sounds and volume levels played back in their assigned locations.

A lot of those differences are *due* to differences in freq response, WHICH IS THE DIFFERENT LEVEL OF A PARTICULAR PART OF THE FREQ SPECTRUM AS COMPARED TO ANOTHER PART.

Plus, you could also say that hey, a lot of those differences are due to phase differences inherent in *most* (not all) speaker manufacturer's designs.

(Phase variance is also created any time a "filter" is applied to the audio signal. Crossovers, low/high pass filters, "cinema eq" etc.)

The problem? Only Vandersteen, Thiel, and Dunlavy, among a very few others, actually make "phase coherent" and "time aligned" speakers. So... if phase (and time alignement too) mattered that much, then people wouldn't be buying B&W, Paradigm, NHT, etc.

Speakers are a different matter annyway, simply because of how they interact with the room.

But, for source components and pre pros/receivers, I believe that the differences that people can actually hear between quality components are so small as to be meaningless. (DSP algorythms are different, just straight stereo, 5.1 DD, DTS, etc.)

And as for people who can hear the differences between *quality* solid state amp designs under normal operating conditions? More power to you, but I think you're fooling yourself. Now, if the amps are driven *hard* enough to detect the nature of their failure ("catastrophic" or "graceful"), that is also different.

A *lot* of people consider amplification a commodity. Not a lot of difference between quality amps.

And I know this from experience. Have had Acurus amps for quite awhile. 100x3, then 2 200x3's, and now 2 A200x3's. Liked 'em so much I tried their big brother the Aragon 8008x3. Big and bad and beautiful power amplifier. But after 30 days? Couldn't detect any difference so stuck with the Acurus.

This is a philosophy thing. I believe what I believe, and you entitled to believe what you want to believe.

Bottom line is that I don't go chasing component after component because I believe I'm going to get that much more benefit in sound quality. (Digital vs analog *does* matter. Analog rules. But differences between DACs in *quality* components *of the same technology generation*? Ain't going to convince me that matters. But I still want 24/192's... )

I go for ergonomics, quality of construction, manufacturer reputation, reliability, features, remote considerations. I put heavy duty consideration into the reviews I read, even if I don't believe all the sound "quality" differences that are noted. But because the professional reviewers out there do come across a hell of a lot more componenets than I ever will, so judgements of all those other items that I look at will be included. I also put heavy duty emphasis on audioreview.com. If a sizeable proportion of the actual *owners* of a product like it, more than likely I will too.

But of course, ymmv, and it will...

Yer foolin' yourself if you think you can reliably calibrate sound levels without a sound meter. Can't remember the source, but I read an article several years ago that demonstrated the need for this to be accurate.
They took a room, with two 5.1 setups. One was a high end speaker system (can't remember the brand). The other was a set of cheapo Rat-Shack small speakers. The RS speakers were calibrated to within 1 db. The others were left mismatched, but still within a small range (can't remember, something like 2-3 dB). Both sets were hidden from view by acoustically-transparent screens.
The participants consistently picked the RS setup as having the more convincing soundfield.

Note, this doesn't mean the best, most detailed sound. When watching a movie, you can have the most revealing setup in the world, but if pans change in volume or character as an object moves, say form left to center to right, the illusion is broken, and you hear the speakers instead of the movie sound.

So, if we can't even reliably calibrate speakers by ear to within 1 db, how can anyone be trusted to know that Amp A sounds 'more detailed' than Amp B, when they heard them on different days, different speakers, etc??

Today, any quality differences between high quality amps are largely neglible. The interaction between a given amp and a given set of speakers is far more important. All speakers have a widely varying impedance across the frequency spectrum. For example, my Martin Logan reQuests are 'nominally' 4 ohms. But, this impedance drops to as low as 1.2 ohms at some freqs -- damn near a dead short! This drastic change is enough to alter the performance of some amps, and even make some give up completely. So, even though an amp meets certain specs, it may fail when hooked up to systems like this.
So, while I might prefer Amp A over Amp B in my system, I don't think this applies to all other systems. Likewise, of the set of Amps that can handle difficult loads like MLs, I think the sound difference is very marginal, if audible at all.


[This message has been edited by bigmac (edited August 04, 2002).]

Good post Kevin. I'd have to say I pretty much agree with you.

I have to say I don't trust anybody's judgement on sound quality for multichannel output (even my own) without the use of an SPL meter.

And yes I completely agree with this statement:

I must say, that changes what I think about everything azryan has said up till now, and tends to make me take all his statements with a big grain of salt.

[This message has been edited by bstan (edited August 05, 2002).]

I see here, and on other boards, that users either "prefer" the analog RS meter, or go as far as saying that they are "better" or "easier to use" than the digital meter.

I have a digital RS meter, primarily because they were sold out of the analog meters the day I bought mine. To use it, I set the range at 70, the weighting at C, and the speed to slow. Then I simply adjust the volume until the inch high numerals read 75 for each channel - Pretty easy for me.

I'm not trying to start a "Tastes better-Less filling" argument over preferences - Other than the analog meter being about $10 cheaper than the digital meter, what else, if anything, makes the analog meter "better" or "easier to use"? I'm sure some folks prefer the analog because it is more like the kind of equipment they are used accustomed to using, but I fail to see where that makes it better or easier to use for an inexperienced purchaser to use.

Any thoughts?

Thanks!

AHwww. Its a digital READout!
Your post made me wish I went digital. The numeric read sounds great and the way you describe the rest sounds like it works just the same. When I asked the RS employee to tell me the differences between the two.. He could not tell me stated he did not understand them and had never used them. So I went with the less-expensive buy, since I've spent enough lately and knew the analogue was in use to satisfaction, by many.

Since the analogue meter screen has no hash marks for smaller increments. Sounds like your digital would be more accurate.

bigmac,
One... since you don't know the source, I'm sorry but your example is totally pointless.
Who knows how that test (if it even existed as you wrote it) was set up?

I'm sure I would have picked the system that was set closer to correct over the one you said was set wrong on purpose if asked which had the more balanced/solid surround field.

This doesn't prove that the SPL meter calibration method was more accurate than by ear. This test has nothing to do with debating that issue. The test (as you described it) is only showing that a level matched system is important to a surround set up.

I totally agree with this.

Personally I use a 4.1 system w/ Newform Research speakers in phantom center mode (not that I recommend this set up for everyone, but more speakers doesn't simply mean better).
This creates an inherently perfectly matching center in both tone and volume to my mains. Panning is inherently perfectly seamless also in my system, and with my rear Newforms ~110 degrees behind dead center the surroundfield level matched by my ear is also seamless within the general 'sweet spot' of the couch.

Matching the sub is much tougher of course. I use dual DIY sonotube subs in the same corner of the room. I have the phase flipped on them to blend into the mains that are ~6' from the nearest walls, and floor to ceiling bass tube traps to cut up the standing waves (which would otherwise distort my ear's judgement AND and SPL meter's reading).

Since the rat shack SPL meter is so inaccurate on bass (and yes I know about the correction chart), I prefer to judge by ear the blend of bass on many diff. tracks of CDs and DVD's -which all have diff. levels of bass mixed anyway, so no 'one' level is ever going to be exactly right in any system.

I certainly would like to set this even more accurately if possible, but it can't be done.

Ever hear a combo DD/DTS DVD w/ diff. surround/sub levels on your system? One's closer to right than the other, even though both are on the same SPL level matched system. But which is right no one can say. Take your pick. Your 'preference' won't be wrong.

Look at the advice of steves (who believes he disagrees with me)...
He says level match w/ SPL meter (ignoring my point being that you can't know you have correctly done this), and THEN tweak your system by ear per source, defeating the whole point of claiming that level matching w/ the SPL meter is so critical!
He then explains how a properly calibrated system should generally sound. Which I think everyone here agrees with, and no one is questioning. Questioning his grasp of my debate points.

Wow,
Sad.
Ok, some of your disagree w/ me. Fine..., but then you neglect to actually explain how I'm wrong -making your opinions baseless and flaming. You can do better than that can't you?
bstan. You made just enough effort to post a generalized insult as to the quality of ALL my previous posts? Low. Very low. And quite without a leg (or fact based point) to stand on.

Here's the plain and simple version of my two main points.
"There's a TON of variables involved in level matching your surround system w/ an SPL meter, and NO consensus as to exactly how to do it."
and
"Beyond this, there's many other huge factors that more than counter any sincere efforts to calibrate you system w/ an SPL meter".

Many of the variables I posted have already been posted in this thread by others. By people who are very much in favor of SLP meter calibration, yet don't see these variables as any kind of a flaw in the process actually being accurate.

Like I said -I'd LIKE to be in favor of SPL calib. myself.
I've got a rat shack 5 min. away, and enough money for the meter any day of the week. I've thought for years about getting one because of all the recommendations.

Sadly, all these MANY variables that keep cropping up (and seemingly ignored by everyone as irrelevant) make the 'calibration method' highly flawed, or at best of little sonic value even if it were perfect. -unless your ears are just awful and your own judgement of the test tone's volume is way way off.
Someone could have mentioned this in a point against me.
I concede to this being possible though, so -'too late'.

Here's one more variable (and please go back and read all the others I posted if you want to debate this with me, and leave the personal insults OUT of it. You should be able to do that.)

Do you all calibrate w/ the meter dead center in the prime sweet spot? Great, but unless you all watch movies alone, or you insist on always sitting in that 'sweet spot' you just threw off your calibration in yet another way by sitting even slightly off to one side -(and screwed up your distance settings or digital room correction systems too which are diff. issues, but in the exact same vein).

And not to change the subject but as for you who think all amps bascially sound the same. You're just flat out wrong, and none of you should then own amps that are anything but the cheapest available, or you'd pointlessly be wasting money.

My new eARTwo digital amp was instantly FAR FAR better than my previous and long broken in Audiosource digital AMP7 -in every way. My wife and I were both shocked at the difference. It's incredible how much better my 950 sounds through it. And the 950 certainly not the best sounding front end in the world -great as it it.

And compared to my amp before that, my AMP7 had a much tighter/faster low end, slightly more recessed midrange, and faster, more transparent yet slightly less smooth highs. This is at at any point in normal volume range so don't fool yourself that level matching played any part in the issue either.

Azryan, Tsk, Tsk, is it because its Monday?
You know I am the first to declare (regarding myself) I DON’T KNOW NUTing hardly yet. But I’ll pick up the gauntlet for a quick point. I find it enlightening that you have never used a meter, and personally I think you should add that in as pertinent tidbit, when discussing the merits thereof. I see your theory, and I see very valid arguments for your points. Particularly in regards to all the variations using a meter has to account for. After all, we did make our first shots to the moon, all based on understanding parameters without having first hand experience of them yet.

But I’ll take it on faith that you and your wife hear a difference when you added in your new amplifier, (and I believe). If you’ll take it on faith that my husband and I heard a difference (for the better) after calibrating our speakers.

..these results may not be representative of everyone choosing to follow our diet plan, and did include a weekly regimen of exercise

You might want to re-read what I said, which was- IF you wanted to tweak the levels. I don't. Most folks only make small level adjustments to the center and/or sub. By the way, a phantom center is great as long as there is only one (or two of you close together) occupying the "sweet spot". Having a center speaker works much better as it will anchor the dialogue and central sound effects way better for people sitting "off-center". I do like a "phantom center" when I'm listening to two-channel music.

Gracious... All this furor over a little meter...

Azryan, I think much of the heat that you are taking is because, as Smart Little Lena noted, you haven't actually tried using a meter. Absolutely, there are differing opinions on how to "properly" use one, of that there is no doubt. You can always find one more unaccounted-for variable. Hell, you can probably find a dozen more without even trying, even beyond the ones you've already named. Anything can and will have an effect. Will the folded shade on the lamp next to the couch cause more distortion than a smooth lamp shade would? If you shave the cat, will the reduction in cat hair in the air help with airflow through the ports on the speakers? At some point, we all have to quit second-guessing ourselves and do some listening. If I'm reading your posts correctly, you have decided that the variables you've pointed out make using a meter pointless in setting speaker levels. Your decision is atypical, as most people find the meter a helpful tool for quickly getting their system adjusted, but we all do some atypical things from time to time. You did point out that steves had the right idea in his response to your original post -- allow yourself to tinker with it, don't take the meter's word for it. Since that's the approach I use, I will agree with both of you (steves in particular, as I use the meter to get my starting point). I know that you tend to get very "in" to what you are talking about, and I recognize what you're going for, but you are getting flamed (heck, you even predicted it in your original post!) because people get the impression that you are saying "don't use a meter, it's stupid!" when you haven't actually tried one.

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gonk -- Saloon Links | Pre/Pro Comparison Chart | 950 Review

Thank you Gonk, best laugh all Monday!. Don't think I'll mention this story to the boys...as I have a cat and he would be very offended. Plus he never stays in one place for long.....drat...another variable..and then they might think of the super glue....
Your a sweetheart Gonk.

-- Glad you enjoyed it! I have two cats myself, both long haired (a Persian and a Maine Coon), and I can guarantee that both would be highly offended at the idea.

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gonk -- Saloon Links | Pre/Pro Comparison Chart | 950 Review

Thanks Gonk. This thread was starting to drift or get too technical. Either use one or don't. Personally, I did and found improvement, IMHO. Just my 2 cents. Was it Monty Python? "and now, for something completely different..."
DMC

perhaps I should have said that we are splitting "hairs" here I respect everyone's opinion here.
DMC

Hello, I hope everyone is well.
In the professional realm,meters, from the most basic SPL through spectrum anylizers and TEF boxes and beyond, are used as a starting point when dialing-in rooms and gear. It gives you an unbiased reference. Then,the Engineer tweeks things to his/her own liking. Meters give you good, useful information and anytime I change any parameter in any listening space I always 'take the system back to zero' re-meter, and tweek the system again.
IMHO this technique gives a good reference that you can then adjust to your own liking. It keeps you from trying to adjust a horribly out-of-calibration system. When you start off very far from metered calibration, it makes getting good results just that much more difficult.

Az- Sidenote. I completely agree with using a phantom center for listening to music. When using a phantom center for surround applications, aren't you losing the artifacts that were specifically mixed for the center channel? If not, wouldn't one of the digits in the 5,6,7.1 formats be extraneous? Just a thought.
Until next time,
Mix

steves,
I DID read what you wrote. The word 'IF' in your statement doesn't invalidate my statement and I didn't miss it when I read it the first time.
It implied that you condone altering the levels after SPL calibration. I see from your later post that you do not. You needed to clarify that though to make that point.

Now you're not just disagreeing with me, but also all the other people who adjust their levels slightly per source after level calibration (by ear of SPL meter) -which I'd bet is most of us here. At least many.

Lena,

Why the "Tsk, Tsk"? You seem to be criticizing me for discussing the use of an SPL meter when I don't use one myself -as if I didn't mention that fact, or I don't know what I'm talking about?

Obviously I never hid that I don't use an SPL meter, and in fact stated it outright. That's how you knew I don't use one- 'cuz I said it!?
No deception or anything on my part.

I understand very clearly how an SPL meter works. How they're meant to calibrate the speaker levels. How the results -if completed as intended- will improved a surround system. Seriously "No offence",but most likely more than you yourself do.

Most importantly (IMO) I understand how lots of variables alter this method into inaccuracy.

I've yet to be told (civilly or uncivilly) how to take into account for all these variables (or ANY of them individually even) and factor them out of the process.
I'm prefectly willing to learn from you or anyone on this issue.
So far I think I just put thoughts in people's heads that they'd rather not think about.
Uncertainly often causes uneasiness which comes out as anger -which you see here from others who are ticked at me.

I coulda' posted nothing, or I coulda' posted "Yeah, SPL meters rule! Everybody hug! We're all right!"

I challenge people to think deeper and lots of people hate that. Some people learn something though. I know I have when I've been challenged in the past (and I'm sure in the future).

I certainly don't know squat compared to some of these elec. engineer / custom modification / DIY speakers building / super high end audiophiles who post on certain other forums.

I've said things in the past that I knew I was far from the first to say -things I thought were just 'understood facts', and they busted me by telling me the details of what I never thought or knew about, and I learned from it. And I've busted other people on it.

Some like to learn stuff on forums, some just like to post to chit chat and be friendly w/ people who bought the same stuff they did.

You do seem to understand the points I'm making about the many many variables in the calibration method.
I believe you mentioned one yourself about pointing the meter up or pointing forward, but maybe that wasn't you who said that (I can't read the past posts while I'm making my own post -they don't show up on this comp.). No offence if it wasn't you ok?

I'm also NOT telling you that you did not hear an improvement when you used your SPL meter to calibrate your system. I trust that you DID. You misunderstand if you think I disbelieve you. I have no reason to not take you at your word. Nothing you've ever said has ever seemed untrustworthy IMO.

BTW, of all the mentions of rat shacks' SPL meters, 99 times out of 100 people rec. the analog over the digital, so I wouldn't worry about not having the digital model.
I believe the 'gist' of it is that the analog meter is more accurate since you directly see the meter needle w/ your own eyes, whereas with the digital model reads the analog input and tells you (presumed w/ less accuracy) what it thinks it read.
A cleaner reading from the cheaper model.

Gonk,

No need to worry about me getting flamed. I knew that I'd be in the minority on this issue, and I took a guess that some people would assume I'm telling everyone that they're wrong in using an SPL meter and turn 'mob mentality' on me.

I'm glad you can see what I really mean regardless if you agree or disagree w/ me.
Yes, I'm very 'forceful' a lot of times, I can't disagree with you on that. But you bring out the worst AND the best in others when you challenge them. I intend the latter (most of the time -heh).

Just as you stated all kinds of variables that are funny yet actually do effect things, you see my point about how you just have to accept variables that you can't correct for.

Let me ask everyone... how WRONG were you when you went from 'by ear' calibration to trusting the SPL meter results? And how do you know that factoring in some/any/all of the variables I listed, that you are still far more accurate (if any more) than you could get by ear?

Personally I'm just curious at how bad you all feel your ears are at listening to test tones and how accurate you think your specific method ('cuz no two people here do it exactly the same) of SPL calibration is.

It's not a big deal for me really. I would only be using a meter to level match my pair of rear speakers and my subs to my mains. My room is totally symetrical so I'm sure the mains and the rears as pairs are the same to eachother (meaning I don't need to guess about a left rear that's farther away than the right rear).

Since I hear a totally solid surround field and obviously specifically adjusted these levels till I fealt that's just what I heard, I really really doubt an SPL meter would improve on that.
Nor would I be confident in the least that the method I'd choose to use that meter would be without it's own equally bad flaws.

-and face it these very tiny flaws are would directly relate to just the sort of 'slight' db adjustments the SPL meter is intended to correct!

MixFixJ,

Since the downmix of the center chan. is totally in the digital domain you don't lose ANY of the information encoded in it when run in phantom mode. I'd be against it if it was a compromise like that.
The only 'red herring' you'll hear mentioned is a 'comb filtering effect' as the center chan. is being projected from two speakers. This you can hear w/ your own ears is not a real world issue (or you'd have heard 2 chan. audiophiles complaining about this effect for decades -where instead you still have some of the VERY best audio systems in the world being pure 2 chan. -not that I'm against multi chan audio).

I highly rec. you try a phantom downmix to at least hear how well (or poorly) it works in your system. You'll learn a lot no matter which you think is better for you since you still listen to 2 chan. CDs just like the rest of us.

I seen a lot of people who set their mains too far apart which isn't too bad when their watching movies 'cuz their center is more of a gap filler than the critical component it should be.

If the mains are too far apart the phantom center image will be more of a dull, cloud-like image than it could be. They mix the center speaker back in and say 'Oh yeah! It's a LOT clearer/sharper and more 'locked to the screen' and without a doubt... it is!

Thing is.. you should be able to get just as sharp/clear an image from your mains if you played with the set up more critically (improving your 2 chan. imaging on CDs in the process).
You won't have that 'locked to the screen' effect though.
But that's not what you should want.

That effect is mainly caused by the horizontal placement of the drivers (in most -not all- center speakers) which is ONLY like that so it can fit on or under a tv. It's NOT because that's a better position soundwise.
It throws more sound vertically than horizontally so the speaker doesn't sound as open or transparent by design (even with the best of components). Look at how Martin Logan has to use cones and domes in thier center speakers to counter this effect on their thin horizontally mounted 'stat panel.

In case anybody asks -"Yes I HAVE used center speakers in the past. Several."

There's just a ton of variables in this too though (you'll notice I'm keen on that word in this thread-heh).
Line source designs like long ribbons (which my Newforms are), Martin Logans, or multi cone/dome arrays are the best for a phantom center (I believe because the two vertical planes of sound blend easier than the circular outputs of cones/domes), but I have a set of Axiom Audio bookshelf speakers (cone/dome design) and find I can also produce an incredibly open and solid front soundfield compared to having a center in the mix.

Psychoacoustics are really massive big brained stuff. The vast details are beyond me, but the extent that I know and that I've heard, I much prefer the inherently perfectly matching phantom center to any center speaker I've ever heard (and I've heard several that cost far more than my mains combined).

The cool thing is that it's free for you to test, and if it's an improvement you just got better sound for free, and can sell that center speaker, save an amp, etc...

Kinda depends on the tv too. When I had a 32" tv and first changed to a 4.1 system to 5.1 it was VERY weird to hear the soundtrack smoothly pan across the my ~7 1/2' spaced speakers (and far beyond them) when all the action was taking place in a ~2' box in front of me.
For exam... someone walks across the screen. The picture shows the person walk across the small screen, but the sound has him perfectly smoothly pan across my entire room -exactly as the mix is designed. Super hard to blend a center speaker in as good, and impossible to blend better. And why add the cost if you don't have to?

Now that I have a 65" RPTV, this smooth/open panning is much prefered (though I prefered it from the begining).

As for surrounds. I use 2 rear monopole speakers 120 degrees behind dead center. Owning plenty of amps and plenty of loudspeakers I've tested 6 and 7 chan. set ups and found them to be less smoothly blended than just the two rear Newforms blending into the mains.

I was all set to sell the rear Newforms and get 4 all new side/rear speakers (when I compared the 4 identical speakers I own now), but it was just unnecessary to add more when the only goal is a totally solid surround field NOT any specific number -and 4.1 was enough for my 17 1/2" x 23' room.

If you have a VERY large theater and want the sound to be diffuse and as even as possible through out the whole room, you should add as many surround speakers as you can preferably dipoles throwing sound all over the place before it even hits your ears.

This is the design of a movie theater. They need all the seats to be about the same or everyone would kill to sit near the center of the room (which pretty much happens anyway), and this is one of the reasons why even so-so set up HT's sound far better than movie theaters. I don't use THX or movie theater in general as a reference point.

I think HT crazed answered that one when he started this thread! Myself, I did set levels by ear initially and wasn't very close (according to the meter). Wasn't very happy with the results either. If you use the SPL meter you will eliminate one of the biggest variables going- our inability to set levels by ear only. IMO most of us just can't do it. Go get a meter az and give it a try. The way I see it, I'm way ahead of you- I've already done it both ways

When I started this thread, it occured to me that there couldn't possibly be anything less controversial I could say than "use an SPF meter, it's a good thing." Especially since every receiver or processor manual has similar instructions on page 1.

Those following my posts in the past will know that being uncontroversial isn't a major motivation of mine. (And I did feel a bit ashamed.) But I just wanted to add some emphasis based on personal experience for those holding out.

If there can be hot debate on whether it's a good idea to use an SPF meter, I can't think of any other topic that could possibly go unchallenged.

Seperates sound better than receivers? Quality interconnects are a good thing? Bombing poor third world countries is a bad thing? OK I give.. Let the debates continue!!!

Az,
Interesting stuff on the phantom vs. actual center channel. For a change, I don't disagree with you! Although your method of 'challenging' others I find questionable. To each his own. I have listened to my system without the center using phantom mode. It works very well. My components are all matched and the levels balanced, so the sound field is seemless. At this time I'll continue to use my center channel as I like the way it sounds. I'm changing my projection unit in the next few weeks so my use of a center channel may change.
Back to the subject. I, personally, would advise the use of an SPl meter for the reasons that I stated above. You might be pleasantly surprised at the results. You could also then speak from direct experience with it's use rather than conjecture. This would only strengthen your argument and knowledge base.
Mix

I coulda' posted nothing, or I coulda' posted "Yeah, SPL meters rule! Everybody hug! We're all right!"

Thats a good line and your 100% right about the center channel. I use phantom mode all the time and its great.



[This message has been edited by e-dogg (edited August 06, 2002).]

HTcrazy,

Yeah, if it wasn't for my big fat mouth I'm 100% that this issue would be as completely uncontended as you assumed it would be.
Sorry if that upset you or anything. Not my intent.

steves and MixFixJ,

You both continue to rec. I use an SPL meter ignoring my list of variables as being any kind of issue.
(Please don't take this to mean I'm mad here or anything).
I assume then you consider all of these variables myself (and other before me) as irrelevant, and your position seems to be (correct me if I have this wrong) that no matter which way you choose to use an SPL meter you pretty much can't go wrong and you'll in fact be totally (or at least very close) to accurate and without a doubt end up with results that will surpass a 'by ear' setting of levels by hearing the test tones.

Is this correct?

And MixFixJ,
I don't mean to 'challenge' people in a bad way (like to make them feel bad or dumb or anything), but rather to get people to look further into an issue than they normally would (as this thread would have been), and possibly learn more than they knew the day before (whether from me of anyone else). Something I think far too many people don't challenge themselves to do these days.
I think some out there may agree with this point (esp. those in working in our nation's school system).

I certainly have been open to having someone explain to me the 'correct' procedure of using an SPL meter and/or explaining how it's wihout a doubt better than a 'by ear' method (A method I also 100% believe to ALSO be somewhat flawed -my debate being over which is more flawed).

No one's done so to my dissapointment. I've just gotten some people mad at me, and some people just repeating that 'I should use an SPL meter' -clearly not understanding my point of contention about it's use, and claiming 'conjecture' yet not able to technically make any points that contradict my previous statements.

Azryan, I just posted I liked using a meter, I never advocate my cup of tea well blended for all.
I shouldn’t be brave enough post any opinion, as I am skating on the barest base of knowledge in A/V, and don’t I know it! Facts right now tend to slide away from me just as I'm reaching for new ones.
I agree completely with your challenge to think deeply, otherwise I would still be lining up for the latest Bose model demonstration at CC or I’d have my baby sister’s Sony HTIB in my Living Room. Or even more likely, - I’d probably be just rolling my eyes at my guy, saying just drop me at the clothing department if your going to look at those things again! Some part of me in my recent past, dug in my heels, and said, there has to be more to AV than THIS.!!!! I will never understand why I do the things I do, like becoming interested in a subject heavily dependent on knowledge I have no grounding in, - but for me, -‘The journeys the thing’, and unwisely or not I don’t’ have the sense GGM to be intimidated by that intriguing side-trail I see in the road. I was just surprised to read you had never calibrated. One of the first things I ran into was THE GREAT cable/interconnet debate. So typical to me, I said let’s pull out all the cable we can find, cause I want to see for myself.
I did not realize I had put on my flaming party hat, I am now posthaste to the kitchen where the fire extinguisher lives.
You asked: ‘how WRONG were you when you went from ‘by ear’ calibration to trusting the SPL meter results?
For JUST me, very wrong. I’ve always had personal preferences on how a sound system sounds to my ears, yet never bothered to learn, WHY a system sounded better to me?
Since I have not spent years tweaking the nuances of 2 channel, stereo, (CD’s). I was first playing in the DVD boom and bang range of predominately Home Theater type stuff. I think I made a newbie’s mistake of equating all surrounds working noticeably with how riveting or enveloping the movie experience would be.. Therefore I tended to keep pushing the surround db’s up. Many DVD’s really don’t make all that much use of the surrounds, so I’d push and push, and then put in Disc with DTS recorded. Whoop-see, - back to tweaking the other direction, to keep from waking the neighbors with the long distance effects mainly of LF through the mains and the SW.
Over emphasizing my surrounds would periodically land on a serendipitous blend with an individual recording where things opened up and life was good. Unfortunately, 90% of the time, since I did not tweak for every single thing I listened to, I ended up with my levels grossly out of whack.. I thought I was tweaking to an effect which I felt would be pleasing - more surround on movies. After calibrating, very quickly, it was clear…I had destroyed the soundstage for most of my listening.
Even though I had purchased a meter myself before my 950 came, it looked intimidating and I was waiting on my husband to sit down with me on this, I honestly felt at that time, how much difference can calibration ultimately make because I trust my own ears and had vague notions that I could create time delay effects using trim to account for my not so optimum speaker placements and other such thoughts on how to handle aspects and variables unique to my room.
Using my trim this way, for my level of expertise, was heavy handed and grossly inefficient lacking in finesse. Akin to using throttles to bank a plane if you were to lose aileron and rudder control.
Right now I only have my beginner’s ticket and if my plane is in balance (in this instance, calibration)
I need less pressure applied to get movement in any direction I want. You probably don’t need that central fulcrum to start from; since I am not seasoned, - right now I do.

Now If you ever need my expertise, my next classes will be held starting Aug 28, e-mail for scheduling:
A sampling of courses offered this semester:

Topic 1 – The toilet paper roll: Do they grow on the holders?
Round table discussion.

Topic 2 – Loss of Identity: Losing the remote to your significant other.
Helpline support and support groups.

Topic 3 – Is it Genetically impossible to sit quietly as she parallel parks.
Driving simulation included.

Topic 4 – Learning to let go of impossible tasks including keeping flighty brains on serious topics.
Shock Therapy sessions and /or full Lobotomies offered.

Lena,

How do you know that your spl meter readings you've taken are correct? Isn't it that -
1 -faith that it was done exactly right, despite a bazillion variables that can't be accounted for?
and
2 -to your ears, you find the surround field now much better than before?

1 -this answers itself. Too many variables to ever trust your results we're accurate (as I would mistrust my own readings for the exact same reasons).

2 -how can you trust what your ears hear now sounds more correct, when you were wrong about trusting what they heard before as more correct?

It sounds like (but correct me if I got it wrong) you 'kept messing' with the levels all the time (or frequently), and now that you have an SPL meter, you've set it to one exact set of levels that also 'to your ears' sounds correct, and now you don't mess with it at all -or 'not much', and then at least you know what the original spl settings are so you can change it back if you want.

I'm more than willing to trust your claim of improvement if this was the situation.

Have you tired to sit dead center (I assume exactly where you spl meter was) and listening to test tones judge for yourself the levels that they should be set at, so that when set -as you tap the 950's remote to quicky cycle through the speakers, they all sound evenly leveled... and then don't mess with that setting and listen to clips of assorted DVD's?

That's what I've done, but right off the bat I flaw my results... since I calibrate at dead center, but watch 100% of all DVD's with my wife next to me -so neither of us are sitting dead center.
How do you account for this in your home? Do you demand center seating at all times or ignore this proven error?

An SPL meter is incapable of correcting this flaw as it is w/ many other flaws that 'real world' just can't be gotten rid of.

I don't 'judge by eyes' my distance setting. I use a tape measure... but again from dead center, ending up flawed as I don't sit dead center when watching movies w/ my wife. I don't find this to be a big deal though.

Just like Gonk's jokes about 'shaving the cat' and all that (though I think that might have just been a 'Freudian slip' in his case -heh). You can't account for all sorts of variables, but you do the best you reasonably can.
I just don't find the methods people use in SPL meter calibration to be reasonably without major flaws.

I submit that my set up being a perfectly symetrical dedicated HT room and L/R speaker placement and only 4.1 is probably much easier to judge by ear than a system of varied speaker distances and several more speakers -which sounds like what your system is like (by your wording of it in your last post). You mentioned varied distances, and I assume you have a 5.1 set up at least, but probably 6/7.1. Just a guess though.

I believe an exact one 'correct setting' does not exist. I also believe that the methods people are using here w/ the rat shack SPL meter are too flawed to be deemed correct IF an exact correct setting existed.

I'd love for someone to prove me wrong. I know I've racked my brain on this issue for years.

Here's something you might like to try... have your husband write down all the (spl meter based) level settings (if you don't have them memorized hopefully). Then have him screw up all the setting so that they're obviously 'outta' wack'.

Then you sit down exactly where you'd put the spl meter and try to set it back to the right levels (using whatever 'variable' you used for the spl meter -950 test tones, Avia, V.E. whatever).
Now write that down and compare the settings.

There's a 99.999% chance the two numbers are diff. of course, but listen to a few diff. DVD's and try to guess which one is which (your husband would have to reset the settings) AND which you feel sounds more correct.
I bet you'll have a VERY hard time deciding -esp. if you're using DVD's with varied surround levels (which just throws the whole thing into an opinion question), and in the end you just CAN'T know you which is more 'correct'.

Most of my comments have been about main speaker levels (mains, center, surrounds).
I believe sub leveling is a whole 'nother can 'o worms...

The rat shack meter is progressivly inaccurate between 2-20db from ~80-ishHz down to ~10Hz (and worse down to 0).

I'm guessing no one here corrects for these faulty readings by doing some very detailed math, since the test tones you guage by are an equal output of all these tones at the same time, but then again... maybe they're not?
Are you sure what exactly the chosen test tone is outputting? Some of you may not be.

Then factor in room modes that change the bass level throughout the room beyond the tiny point you SPL metered at.

Then play a CD with weak bass and want to up the level. Then put on the DD intro on Phantom Menace and bottom out your sub.

'Real world' it just works/sounds better to guage by ear by knowing you system inside and out.

How many use wall 8' bass traps in the corners of the room to cut these standing waves? I do, and my bass is tighter and more accurate than it was previously.
How many have thought about how the distance from mains to the sub effects it's phase accuracy?

Now tell me you have have that sub set perfectly, or more prefectly than mine is.
At least think about it before you disregard my comments as being 'not what most people do'.

Most people use TV speakers. Or do you mean most 'HT users'?

Most of them use Bose. Or do you mean 'HT forum posters' like here?

Most of them use SPL meters in assorted methods that all (or 'all but one') must be at least somewhat inaccurate.
They judge with thier ears that this is more accurate than when they judge with thier ears. Odd ain't it?

The people with the most advanced knowledge and radical thinking about hi-fi are by far in the minority.
Note- I don't claim to be one of them, but just possibly more-so than some who assume the majority is typically correct just 'cuz they're the 'majority'.

Azrayan - Actually I don't think your comments succeeded in angering anyone. I should have figured that some of those that fancy themselves steeped in audio knowledge would suffer some phallic shrinkage at the thought of a $40 piece of hardware bettering their own golden ear.

Lena- You crack me up. Thank you!

Az- You keep repeating 'how do you know that the readings on your SPL meter are accurate?' and going on about variables. It doesn't matter if your meter isn't reading an exactly correct SPL when you start. The meter could be off more than 10% percent in either direction without becoming useless. (I can't believe that I have to explain this, but I will anyway.) I'll say it again. You are looking for a reference point in your mains to which you will balance your surrounds and center. Get it? Your meter could say 'x', and if you set your other speakers to 'x' your levels would be balanced. And all of the variables that you mention are relevant to varying degrees, but don't overcomplicate things. The meters have omnidirectional mics so pointing them at the ceiling while sitting in your listening position is a good compromise. As far as other listening positions, you are going to have those very same variables whether you use a meter or not.
The meter is a tool. It gives you physical representation of what you are just 'guessing at' by not using it. The variables remain the same with or without the meter. The thinking man uses all tools at this disposal.
Do what you will, but can we move on to something else now? See you on the next topic.
Mix

HTcrazed,

I never indended to anger anyone and I never claimed to have golden ears. I think you just don't understand my comments or maybe didn't read them all.

How do you know SPL ..Readings..are correct
I probably was not very good at it, but assume with repetition, it will become easier, (although it seemed easy enough) and more familiar.

Faith…despite a bazillion variables…
I would say I’m a control the things “I can change” kind of person, and “not worry about the things I can’t.” (or am not ready to attempt yet…).

to your ears, ..find surround field ..much better..
Yes, is that bad?

How can you trust ..your ears…when your were wrong..about trusting ..before..more correct
I was hearing what I thought sounded wrong, or flat, or dead spots frequently, I could affect it, but not with any consistency…again remember my unfamiliarity with several (novel to me) controls I have no finesse adjusting… and my current difficulties grasping all parameters that might effect how moving one setting can often effect 3 things related.
You might say, I highly recommend a meter for someone like me, and I would not be surprised if I am unlike anyone elseanywhere. I do see that many who appear to me to be at different levels of expertise or for whatever rational suits them, post satisfaction with the results they feel they get from calibrating. I don’t know how else to validate my personal liking for calibration other than the fact that I ponder what anyone has to say on any given subject… then if I have time or ability…test the waters myself..accept/discard and continue on.

..now you don’t mess with it at all-or-not much…
Less, since after calibrating the sound became more pleasing to me, over a broader range of recordings.
I try to be a mouse in those settings now instead of an elephant, for …however long into my future,…it continues to please me.

dead center (I assume exactly where your SPL meter was…since I calibrate at dead center but watch 100% of DVD’s with my wife…neither of us are sitting dead center….
Nope, I’m selfish, you see there is one area all try to claim first in this house, My husband and I sit close together, and we’re the alpha male and female..I let all other ‘ears’ fend for themselves.

I don’t judge by eyes my distance settings
This made me laugh (due only to family characteristics) when we set up the 950, I said to himself,..”Get the tape measure”. His response was in the same vein he treats directions, don’t need a tape measure, its this and this …just set it…..(He was in a hurry to power up). When I calibrated, I got out my tape measure.

have him screw up all the settings so that they’re obviously ‘outta’ whack and try to set it back
Just my kind of game, some long winter night…I love that stuff….when I’m more centered on what’s just right for me, and what works smoothly together to get it there.

guessing no one here corrects for these faulty readings by doing some very detailed math..
Do you mean measuring gain that occurs from the sum of the mains factored in with the SW combined? If I got that right, math is not my strong point and I don’t feel ready to go there yet. My understanding is the Radio S meter, is not the choice if you get into that amount of precision. I’ve seen a Sound Engineers rule of thumb for a +2 or +3 (I think) setting for the SW above the rest of your set reference levels. That this setting or close enough is used by engineers when mixing, and generally works best with many sources. I tried this but changed it back as it was too much for my ears currently.

They judge with their ears that this is more accurate than when they judge with their ears. Odd ain’t it?

That is a GREAT Line, well-said, it’s a mystery to me.

PS. I did contemplate why Outlaw would recommend “point to ceiling” Vs the Meter manuals direction to “point to each speaker”….My logic (not necessarily understandable to any but me, went like this) What I’m hearing is a blend somewhere out there in the sweet spot, so if the sound I’m aiming for is the best blend at that acoustical crossroad I’m concerned with. I want it measured THERE, I felt that pointed to each speaker would weight the results more towards their individual locations. That’s why I went with Outlaws recommendation. For kicks, I should try the ceiling (I meant, towards the speakers)


[This message has been edited by Smart Little Lena (edited August 07, 2002).]

Mix,

Yuo said -"The meters have omnidirectional mics so pointing them at the ceiling while sitting in your listening position is a good compromise."
A good compromise of what? Accuracy? Yes it is a compromise. IMO a big one, and one of many.

And I know that the mic is omnidirectional (well actually it isn't but you're already sick of be being technical), but your ears aren't omnidirectional so the readings taken aimed up wouldn't set the surrounds loud enough for your ears that (facing forward) muffle the rear output.

That's why some hold the SPL meter directly forward. That's why some others point it directly at each individual speaker.

Just one of the many variables you're sick of me mentioning. It certainly would give you very very diff. results though in each position.

Show me how you're right and I'll eliminate it as a variable. I'd be happy to.

You added -"As far as other listening positions, you are going to have those very same variables whether you use a meter or not."
Yeah... That's the exact point I made!

Adding -"The meter is a tool. It gives you physical representation of what you are just 'guessing at' by not using it. The variables remain the same with or without the meter. The thinking man uses all tools at this disposal."

A knowledgable man doesn't bother to use a flawed tool. Maybe you don't understand that the processor inside your skull and microphones attached to the side of your head haven't been proven to be less accurate a judging the speaker levels than the proven flawed SPL meter.

Lastly stating -"Do what you will, but can we move on to something else now? See you on the next topic."

Who's stopping you from moving on? What of weird thing to say.
You don't have to post or even look at the thread, and I'm not stopping the existance of other topics from being discussed. Not that there's anything really 'happenin' anywhere on the Outlaw forum right now.

Lena,

My question about 'how do you know your reading is accurate' in NOT a fault with you. It's the many faults in the method.

I guess I mentioned you 'meter pointing' question when I posted to Mix. See he rec. pointing it up. You didn't. That means if he calibrated your system with the same meter he'd set if diff. than you.

My point being that neither of you could prove you're right or more right.

Personally I think pointed forward would be more correct (kinda-sorta), so I would change it if I were you.

You're really open about being a newbie, but I think your willingness to 'look deeper' will quickly expand your knowledge beyond many here (forums in general) who "heard it one way" (whateverthe subject) and lock that into thier brains as the absolute truth.

The sick thing is the more you learn about the infinite variable of audio, the more you find that damn near anything 'might' be true... or false.
And nobody ever really knows for sure just what they just heard. You, me, anyone. It's crazy.

Az- I don't see what the big deal is. You argue from never having tried one.

I 1st tried without one. My system sounded "good" to me at that point.

I then got one, and *much preferred* the results after I had calibrated. Better imaging between any 2 speakers, better panning of effects between speakers etc.

I then used it to do such things are properly set the phase between my subs and mains. You can't argue with that one, because it's a simple comparison of the level of the sub alone, the mains alone, then the sub + mains. The latter must be higher than either of the former. I tried many time to do this by ear with the signals on Avia, VE, S&V, and I was always wrong.

Also got a BFD parametric EQ to mellow out some of the room induced peaks with my sub. Again, it sounds better to me with these changes than without. But you have never compared so you are arguing with theory that in theory (!) does matter, but in the real world, your "variables" don't influence the measurements enough to give you a *worse* answer with an SPL meter than without.

And as far as the SPL meter getting worse results at lower freq, that is true. However, the sub signals that are on test DVDs or even most pre/pro-receivers are still random white (or pink) noise (can't remember which) just at lower freq. So because of the *range* of freq that is included, the error is still less than 5 dB or so. That is *still* way better than most people can do by ear. Especially since the ear is less senstive to low freqs than higher.

You can still say, phooey on yooey, I've adjusted my sub by listening to a mix of movies and music to get the level I like. That would *still* be the last step I would suggest. Just that you'd be changing from a known reference point.

SLL,
In answer to your questions above:

1) the real question is not whether toilet paper rolls grow on the holder, but whether the natural state of the universe is to have the paper roll over the top or fall from the bottom.

2) the man must have the remote. always. otherwise we explode (and i understand it's a real mess to clean up).

3) yes. (some answers don't require a complex explanation.)

4) i have no doubt that a lobotomy would be beneficial for me. when can i sign up for the class?

Kevin,
Your post makes far too much sense for Az. I made some of the same points earlier, but to no avail. Az would rather listen to himself (herself?) talk than try the meter and know for sure either way.
Az.-Talk all you want. Until you try it yourself, all of your arguments are baseless conjecture and hot air. RAMBLE ON!
Y'all have a nice evening. See you on another topic. This one is used.
Mix

I don't like broccoli.

------------------
Matthew J. Hill
matt@idsi.net

Ah ha! Now we are getting somewhere. Matthew, I have never tried broccoli but I am going to tell you why you actually like it. You see, I used to be like you and all of you other uninformed plebeians. After hanging out at some very gourmet, probably too intelligent for most of you, forums I have come to the conclusion that you do like broccoli. I can't really dumb it down for you but chew on this (no pun intended) for a while. When you eat broccoli there could be millions of factors messing it up. For instance, have you ever tried changing the mouthwash or toothpaste you use to another brand? Do you live in a salty air state, polluted state, high elevation...? Are you positive you are eating fresh broccoli or non spoiled broccoli? What about the fork you use to eat it? Have you tried a different metal or perhaps a different dishwasher detergent? If you use your hands maybe you should ask to have someone who likes broccoli to hand feed you since their skin flavor may be better to handle broccoli. Have you ever done a DBT with broccoli and another food? I mean a real one, with scientists conducting it in an airtight, germ free, soundproof room? Another thing to think about is where are the planets aligned when you eat broccoli? Astrology and Astronomy changes our mood and taste patterns you know. I find it preposterous to make such outrageous claims and not even tell us under what type of sky you are eating it. I think you see the point I am trying to make, which is you do in fact like broccoli.

Alright, I've been gone for 10 days and I had to get all of my smartassness out of my system. Its good to be back. SPL Meters Rule!

Jed, you rule!

Everyone who keeps telling me 'I don't know what I'm talking about because I have never used an SPL meter' clearly are unable to grasp the points I continue to make about how the USE of said meter it wildly flawed -therefore by even the most rudemetary scientific methods of testing -totally pointless and invalid as it's results could NEVER be accepted as anything close to accurate.

And NONE of you have shown anything yet to contradict this F-A-C-T.
You all use diff. methods using the same exact meter, and in the end trust you ears that it sounds better, but you didn't trust your ears to find through 'by ear' experimentaion those exact same levels 'where is sounds the best to you'.

Kevin,

"I then used it to do such things are (as)properly set the phase between my subs and mains. You can't argue with that one, because it's a simple comparison of the level of the sub alone, the mains alone, then the sub + mains.

Sorry, but adjusting the phase of your sub is not that simple as taking sound pressure readings. You don't understand this subject if you think it is that simple.

In addition -the readings which are taken from the summed bass pink noise read by a meter that's progressivly more inaccurate as it reads lower and lower bass (all at the same time so you have to 'guess' at the average SPL), and also varied by the position of the meter being pointed up, forward, or at the sub (all giving ADDITIONAL varied readings), in addition to having diff. levels from your pre/pro and diff. test discs (MORE variations), in addition to you admitting to after all this ('technical' method) you still alter the final setting whenever you heck you feel like.

How can you possibly believe that this method's anything close to accurate?
How can you prove that your own previous 'guess' at a proper bass level is more wrong?

You said yourself you 'know you're right now' because it "sounds better".

Well, then you should have done more experimentation by ear till your original 'guess' sounded better and better till you reached the same point.

I'm not saying I have some golden ear. To be more clear (anf friendly), I'm saying that I bet YOU could calibrate my surrounds to my mains and integrate my subs by your own ear, and I bet it would sound very close to how I've done it myself.

Just can't possibly prove that your method of using the SPL meter in more exact since THERE IS NO TRUE REFERENCE POINT when actually listening to CD's and DVD's.

You can only prove you got "different" results than 'by ear' which I totally believe you did.

Beyond that I think you're just trusting that what you did 'looked more technical' than a 'by ear' (no matter how in depth and carefully concluded) result, so you just take it on faith that you're now right and before you were wrong.

Kevin writes -"I then got one, and *much preferred* the results after I had calibrated. Better imaging between any 2 speakers, better panning of effects between speakers etc."

I have 4 surround speakers in a symetrical room. The only 2 settings to calculate by ear or meter is L/R surround level and sub level.

If my surrounds and sub are 'wrong' (not that there actually is a 'wrong') there's now way I'm off more than slightly (+/-Xdb).

Based on the wide array of methods diff. people here use with their SPL meters (which MUST result in just as large +/- variations as 'by ear'), how do I choose ONE method and know that the final result is 'more correct' than any other?

I've been asking for someone to tell me how over and over again.
None of the people who are sick of me have been able to answer this, and after giving everyone more than plenty of time I'm sure no one here is able to.

My search for a method to more accuratly calibrate my system continues. It has NOT been found here.

I hope some of you bother to 'think' about the details of why you do a lot of the stuff you do. This 'lack of thought'is what leads to all the wacky 'snake oil' crackpot audioproducts that suckers buy because they don't look deeper in to 'how' it works... or doesn't.
Open your minds.

Az- If *you* had an open mind, you'd actually try a sound level meter before trying to come up with a whole bunch of excuses why it *doesn't* work.

I bet your the same guy who refuses to use a thermometer to measure a human's temperature too because:

1) Each person has their own inherent body temp, so how can you know what yours should be anyway?

2) Each thermometer is manufactured ever so slightly differently than any other (manufacturing tolerances) so how could you ever know that the real temperature is what you're measuring?

3) How do you account for the "contact resistance" of the thermometer against the object you're trying to measure? Each person's skin *does* have a different ability to cool itself which affects that variable.

4) As we all know, thermometers measure differently according to ambient temp, humidity, and barometric pressure. Hmmm... Got to take those into account too.

Yet in spite of the fact of how unaccurate I just proved a thermometer to be, they have been used for decades to measure a human's body temperature.

*Don't* use a sound level meter. Don't matter none to me, or the countless others who have gotten good results with one.


BTW, I like fresh broccali with a little melted cheese on top...


[This message has been edited by Kevin C Brown (edited August 07, 2002).]

I for one have greatly benefited from using an SPL meter, like 99% of you out there that have actually used one. I found that my sub settings were WAY to high (about 10 dbs)!

One thing that is slightly off subject, but not really - some of my friends (non A/V types) have occasionaly commented that they think my bass is too low. What they fail to understand is that when you turn the volume up, the bass also goes up. One of my friends inherited my first sub (Polk 10" - not bad), and he likes the settings WAY too high. He likes to hear his thumping bass, even at lower volumes. When he turns it up, the bass is out of control! So when he comes to my house, and puts on some bass-heavy music, he complains that it is too light. Then I proceed to turn the volume way up, and suddenly the bass is slamming!

I have noticed that in my A/V maturation process, bass has become quiter and quiter in my home. That is not to say that I don't like it, or don't have it - I have 2 15" subs in my family room! It's just that six years ago, I would have had the gain on the subs turned 3/4 the way up, and the sub level in my receiver at +5dbs.

When I measured my system with the meter, I found that at reference level (105 db peaks), my subs were putting out close to 115 dbs! I never (ok, rarely) listen to movies that loud (ok, once a week), as I find that smaller rooms like my 15' by 18' family room are uncomfortable at that volume.

The great thing about my subs, though, was that they were still cool, collected, and sounding great!

------------------
Benjamin King
benjaminking@yahoo.com

Dave
Regarding #2. You mean one last grand finale so that we will never forget mans' most endearing characteristic (messy).

Azryan: I should edit my post way back, but you got it. I meant to type trying it pointed at each speaker instead of the ceiling. And I will next time I calibrate to see what I can see.

Matthew, I really think you’re in trouble here. To save yourself from broccoli lovers you may need to resort to the presidential method. Acquire Secret Service Agents to police those florets right off your table!


[This message has been edited by Smart Little Lena (edited August 07, 2002).]

Az,

Sorry, he who speaks from conjecture and not fact (since you have never tried an SPL meter) doesn't have any standing regarding the accuracy of using said SPL meter.

Until you actually use one, nothing you can say will change anyone's mind, especially mine.

I also use a calibrated mic with an MLS based software system to measure many of my rooms acoustic variables so I have a baseline to evaluate any changes I make.

This gives me RT60 echo values, impulse response graphs, frequency response graphs, phase graphs, waterfall plots of frequency over time, exact distance from mic to each speaker.

With these I can identify surfaces causing early reflections, adjust my paramtric EQ to reduce room mode bass peaks, adjust the blend of my sub to mains through an active external xover (symmetrical L/R -24db slope), etc.

And guess what? I still use the SPL meter plus VE DVD to balance the output levels of my 5.1 speakers.

[This message has been edited by bstan (edited August 07, 2002).]

Bstan:
Well said. What software are you using?
Mix

My sound level meter has a silver ear- not quite golden, but close enough.

Has anyone else noticed that Azryan's posts tend to come in pairs? Hmm... Could it be a conspiracy?

------------------
Matthew J. Hill
matt@idsi.net

I tried to calibrate my system last night while pointing the meter in different directions. I tried straight up, down, at the TV, and at each speaker. Guess what changed? Nothing. I guess it really is an omni-directional mic. This isn't a guess, mind you; I actually did this in my house.

------------------
Benjamin King
benjaminking@yahoo.com

Mix,

I started out a few years ago with ETF4 and then upgraded to ETF5 last year.

etf website

This software is quite accurate, measuring to 1/12 octave precision.

Azryan: You´re a bad boy now. Go home!
But before you do, see here what fun you can have with some inexpensive toys:

http://www27.brinkster.com/jmag999/

Life is about playing with cool stuff, right?

Smart Little Lena: You´re so funny! Keep on it!

\\Anders

Hahaha! I registered JUST to respond to the comments made by Az.

I've tuned home and car audio systems for many years, by ear and by SPL meters and spectrum analyzers. I understand your point, Az, about the variables. But let's try this example:

Have you ever had your wheels aligned? The adjustments are very simple. You could even do it by eyeballing. And yet any respectable shop will do it by laser and computer. Why? What about the variables of the car, like tire wear and pressure, weight of the driver, full gas tank or half full? How about the rotational mass of the wheels? Road surface imperfections, wind resistance, humidity...it goes on and on. All of which can cause your car to drift after a perfect alignment, so you turn the steering wheel to correct it. Using an SPL meter is no different.

You use the equipment to set the baseline of what a reference point SHOULD be. There may come a time when you change it to what you WANT it to be. Sure, if your car pulls hard to the right you just crank the wheel to the left and it goes straight. But wouldn't it be better if it just went straight to begin with? If you want to align a car by eyeballing, you could do it - it might even go straight, after a few dozen attempts. But it'd be a helluva lot easier just to use the darn equipment!

!
!!!

Now thats some funny !#@$ Sorry !, didn't mean to include you in the expletive! There I go again
DMC

Oh well,
I'll give up. Some of you do at least see my very specific points and their validity as to how they lead to all sorts of diff. end results -though the meter's the same.

This is why my using a meter is irrelevant to my points.

I could go buy a meter today, as post here at least FIVE very diff. surround/sub settings (same meter/same system/all done 'correctly' only variable "choices" would be the diff.) and none could be certified correct.
None could be called wrong either.
No one gets this f-a-c-t?

This is not conjecture.

The variables I pointed out (and others have pointed out unwittingly before me) are real world facts.
Disprove any of them. You've had many days to come up with something.

Matthew, I don't know what you mean about my posts come in pairs? Is that a joke I didn't catch, or what? "Good thing come in pairs?" No, I supose that's not what you meant is it.

Actually I do this to get my post count up. Oh no..., they don't have post counts here!!! I guess this was all a waste of time! -heh

I seen your posts in the past and believe you have a good mind, and I think we often agree (or come close) most of the time.
On this issue, I hope you took the time to think about the almost endless methods you could use to SPL meter your system and wonder how you're sure you choose the right one.
'Cuz the whole point is to be far more accurate than a 'by ear' guess right?

I won't post in this thread again (which will no doubt kill it).

Actually, this is the very definition of conjecture: "I could go buy a meter...." I don't believe your conjecture, and I challenge you to substantiate your claim.



That, by contrast is a fact.

But I think part of the focus of this disagreement hits at the very heart of high-end audio. Do we want something that sounds "pleasant", or do we want something that sounds "accurate"? If the source is of very high quality, then most everyone seems to jump into the accuracy boat. But, as Az points out, esp. in home theater, different mixes have different amounts of bass/surround/etc. which may not be as pleasant as we'd like. And, of course, a meter isn't going to correct for differences in source mixing.

But I think you go too far, Az, when you scream "THERE IS NO TRUE REFERENCE POINT when actually listening to CD's and DVD's." Given a set of listening positions and a weighting of importance among them, you can define a true reference point: maximizing the *accuracy* of your system over those positions in reproducing what's encoded on the disc. Accuracy is a human-independent measure that can be objectively measured (by whatever instrument, human or machine). And that's what an SPL meter is useful for.

If you don't like what's on the disc, and want to tweak it, then, by all means, go ahead. I have no doubt that you can come up with settings for many discs that you would judge to be more pleasant than what an accurate reproduction of the content would require. But many people first want an accurate presentation of what's on the disc before adjusting their controls for the "most pleasant" setting for that disc. And, moreover, many people find the accurately reproduced soundtracks to be very pleasing.

Az:

1) in recording studios for movies, do the mixers/engineers use an audio setup that is
a) calibrated by ear to what 'sounds cool' or
b) calibrated by scientific measuring equipment?

2) You want a specific procedure for how to use a SPL meter? Look on either the Avia DVD or Video Essentials. They provide test signals, and very specific procedures for how to use the RS meter to calibrate accurately to those signals. They aren't ambiguous. They don't offer tons of choices.

3) You claim your room is 'perfectly symmetrical', therefore you don't have to worry about L and R speakers having slightly different SPL levels. Hogwash, I say. Due to many of the same variables you call on to put down meters, your speakers, at the same offset setting, may still be off. Why, you ask?

a) no room is perfectly symmetrical. Is it perfectly square (I do mean perfectly).
-- Are there any windows?
-- Where is the door? Is there an identical door in the same spot on each and every wall? Doors have different resonant and reflective qualities than walls.
-- Any wall art, like movie posters? Are they in identical positions on all walls?
-- What about your big screen TV? Do you have an identical set on the other walls?
-- your bass traps: where are they? Are they symmetrical throughout the room?

b) the electrical paths in your equipment may not be exact for each channel. For example, following L & R channels out of a CD player into a preamp, through the gain and maybe A/D and D/A stages, then out again to an amp, to the gain stages of the amp.... this path (especially amp gain) may cause variances in sound level, regardless of room interactions.

If your room and equipment do not meet the above criteria (and many others), it is NOT perfectly symmetrical -- and is therefore subject to variations in SPL, even from identical speakers in identical locations. In short, there is no such thing as a truly, perfectly symmetrical room.

Also, I personally disagree with your choice to go without a center channel. While this is more opinion than anything, I feel that a phantom center requires mains that can image very precisely -- which you may very well have. I do as well -- Martin Logan reQuests. With the center off, I also get a very clear, precise phantom center. BUT, move off center, away from the center point, and that strong localization starts to fade. Since you and your wife each sit off center, a center may give a better central image.
Also, phantom centers (and precise imaging in general) work much better with no obstructions between the two mains. Large objects, like your RPTV can degrade imaging focus. I have a FPTV setup, with nothing but open space between the mains.

On another point from one of your posts, you are incorrect about the design decisions behind Martin Logan center channels, like my Cinema center. The cone woofer and tweeter have absolutely NOTHING to do with trying to provide more vertical dispersion. In fact, the speaker is designed to do exactly the OPPOSITE. Ceiling and floor reflections can muddy dialog. The ML centers are designed to provide a narrow vertical dispersion to limit refelections, while providing wide horizontal dispersion to provide a clear center image across the seating stage.

The woofer and tweeter are there simply because of the size of the electrostatic panels. In very large ML speakers, the panel can recreate most of the sound spectrum on its own, negating the need for phase altering crossover networks. However, the panels in the center channels are too small to provide any kind of bass, or very high end. The woofer and tweeter fill in for these areas, while the static panel provides all midrange sound lending ML clarity to dialog (the most important part of a center).

[This message has been edited by bigmac (edited August 10, 2002).]

Ok, I guess I lied. I am posting here again, but only to answer the many questions bigmac asked me. I decided not to ignare him rather than keep my word not to post again. Hope no one flames me for that.

"1) in recording studios for movies, do the mixers/engineers use an audio setup that is
a) calibrated by ear to what 'sounds cool' or
b) calibrated by scientific measuring equipment?"

A). The final recording levels are preference as you hear for yourself in a DD/DTS encoded DVD and the various levels in music CD's. They pobably choose arbitrary 'set' output levels in their playback systems, but what they choose to send to playback play is whatever they feel like. They're mixing the music/soundtrack and decide how loud the surrounds should be or LFE etc...
Like the people who alter-to-taste their home system 'after' SPL calib, which seems like nearly everyone.

"2)-They aren't ambiguous. They don't offer tons of choices."

True, they like most other methods used, chose amongst lots of variables for themselves and tell you 'do this exact method'.
Upon playback of various sources you find a huge range of sub/surround levels -so many teak by ear post SPL meter.

Is it so hard to understand that I go directly to these varied sources and by ear try to find the smoothest average between them. I can only swear to you that my surround set up is very smooth and seemless on avarage.
'Possibly' moreso than someone who chose to calibrate to Avia (etc...) and then listens to all the varried levels of the DVD's/CD's then own, but accepts that this set up's more correct.
I've heard other people's systems. People who have calibrated w/ a meter and have never found them strikingly more seamless or even any more seamless than in my home.

I can adjust my surrounds by ear on any source (as I'm sure anyone else can -I claim no magical gifted ear) so that the surrounds sound too loud AND so they sound too soft. This doesn't take more than a few db (+/-5 at most). If you split the diff. between the two you'll have at the very least -VERY close to perfect surround blending. At most a few db off 'perfect'.
Since diff. DVD's levels vary so much I do this several times and find an average of that. Between them all it doesn't vary too much though really.

Some DVD's will have surrounds too loud, some too quiet, but you all must hear this result too. Some tweak per DVD/CD because you can hear these level diff. for yourself.

"3) You claim your room is 'perfectly symmetrical', therefore you don't have to worry about L and R speakers having slightly different SPL levels. Hogwash, I say.
a) no room is perfectly symmetrical. Is it perfectly square (I do mean perfectly)."

No my room is rectangular. This doesn't bar it from L/R symmetry. Maybe you don't get what the word means?

"-- Are there any windows?"
Yes, two symmetrically set into the far wall behind my mains. They're currently blocked out though to block light and southern heat (damn hot in AZ), not that this is relevent to symmetry issue.

"-- Where is the door?"
It's actually slighlty off center. AH-HAH!! azryan's IS a liar!!! Right?
Well... it's a double door of MDF and is matches the rest of that wall which has additional bracing. It doesn't 'sound' diff. than the wall it's mounted in. At worst I would have to raise of lower my left main speaker one db to counter any diff., and it certainly doesn't sound like I need to, and the rat shack SPL meter couldn't tell me it's one db +/- wrong either.

"-- Any wall art, like movie posters? Are they in identical positions on all walls?"
No none. I could symmetrically place them in my room though if I chose to retaining L/R symmetry.

"-- What about your big screen TV? Do you have an identical set on the other walls?"

Yes, I do. -heh. Again, you don't understand L/R symmetry. Another RPTV behind me would be front/back symmetry, and certainly no HT incl. yours has this. Just look at your own surrounds. You're confusing the issue here.

"-- your bass traps: where are they? Are they symmetrical throughout the room?"

Yes. Bass traps go in the corners of the room to cut standing waves. I have them in all four corners.

"b) the electrical paths in your equipment may not be exact for each channel.-this path (especially amp gain) may cause variances in sound level, regardless of room interactions."

One, yes my wire lengths are symmetrical.

Two, despite this... they'd have to be tremendously diff. lengths to make even ONE db of volume diff. -which is the smallest I can adjust my system and I'd bet it is in yours too.

I hope you see that I did mean symmetrical. Probably shouldn't 've used the word 'perfectly' but it was more a figure of speech. Compared to most HT's (often living rooms and not dedicated areas) my room/seating/speaker set up is very very symmetrical.

About the phantom center... To clarify... my wife and I sit in on a centered 2-seat love seat, but I calibrate dead center (how I sit when listening to music alone). When I say we sit 'off center', it's certainly ain't by much.

I can sit farther off center and still have a fairly perfect phantom center though. The inevitable angle of the RPTV matches the slight emphasis of the L/R main speaker I'm closer too.

"Also, phantom centers (and precise imaging in general) work much better with no obstructions between the two mains. Large objects, like your RPTV can degrade imaging focus."

Very true. if my RPTV was inbetween my mains the phantom center would not work properly and I'd be a moron for setting my speakers up like that even if I used a center channel.

My RPTV getting in the way is an 'evil' I can't get rid of, BUT... it's 3 feet behind my mains, and I use a dampening cloth over the screen when I listen to music, and have a large sound panel above it on my wall 6' behind my mains to dampen reflections.

"I have a FPTV setup, with nothing but open space between the mains."

As I explained I also have 'nothing but open space between my mains'. But how far away is your wall behind your speakers, and how reflective is it? Almost certainly the area of the FP screen (esp. if attached to the wall) is very reflective, and I'll bet you don't have your mains nearly as far from the wall as I do (6'?). Most people think a few feet is enough, or don't have the room to pull them out as far as they should be even if they want to.

I think I've just shown how you challenging my phantom center based on my having an RPTV (and also compared to your FP set-up) was in error.

"The ML centers are designed to provide a narrow vertical dispersion to limit refelections, while providing wide horizontal dispersion to provide a clear center image across the seating stage."

Yes. You are exactly right. But that 'design' is exactly why they added domes and cones to their stat panel that alone has more vertical output than horizontal.

Ask around about why Martin Logan uses vertially alligned domes and also woofers in thier center. The woofers are to fill out the low end the panel just can't do, but ALSO are there because of the radial pattern of output filling out the horizontal output.
The domes are their to make a slight vertical array adding to this. There's no other reason the Martin Logan stat panel needs to be aided on the high end. Look it up.. their old center speaker didn't use and dome tweeters to aid it.
And that's why M-L curves ALL their stat panels -to aid in horizontal dispertion. Ask around. I'm right on this.

My Newform are very diff. They have a 3/4" x 45" monopole ribbon. They have razor sharp imaging and no strong center 'beaming' so the sweet spot of the phantom center if pretty wide. They also have a much flatter freq. responce than M-L do.

[This message has been edited by azryan (edited August 11, 2002).]

Azryan: yes, they do count posts here. You're at 150.

But I guess it should be 75.

(Sorry. Just had to get that in.)

On another note, I've deliberately avoided posting anything serious here because I know I'm not going to change Azryan's mind, and because I personally don't really care if he uses an SPL meter or not (Sorry, dude, I don't mean to be rude, but it really doesn't affect me in any way that you don't use a meter).

I personally think an SPL meter helped my system. There we go; my opinion is known. But my room is far from symmetrical; I do use a center channel speaker, my six speakers are of four different designs; I have different lengths of speaker wire going everywhere, etc. So maybe my way isn't best for all.

And, BTW, why is a phantom center better (if you can get it to image right) than a real center, other than taking up less space? I've heard lots of reasons why it can work, and I can believe that's true, but why not use one if you can?

------------------
Matthew J. Hill
matt@idsi.net

If you are piloting a land yacht of a rear projection unit, there's no place to put the center speaker. That's why, no matter what Az says, he doesn't use one. (IMO)
And yes, it's Monday after a useless post by the Outlaws.
Mix

OK, wouldn't that be an S - P - L meter? Visions of sunworshipers leap to mind with an SPF meter. ;-)

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"Veni, vidi, vino."
("I came, I saw, I drank wine.")

You wouldna be worried I'd be coming after ye now, would you Mr. Mix? tsk,tsk tsk….

Ryan: If you do not use an SPL meter or even any type of volume based analysis, how do you know which frequencies are impacted by room nodes and therefore, how to correct those room problems by using tube traps and other sound absorbing materials? If I remember correctly, you are a huge advocate of correcting the room and not using EQs to correct these room induced problems.

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Take Care,
merc

I don't listen to my system with a SPL meter, so why should I use one to tune it?

Why not trust your ears here as much as in other cases?


brianca..

/sarcasm mode
I don't look at my pictures with a light meter, so why should I use one when I take pictures?
/sarcasm mode

OK, that's an irrelevent comparison (mostly). But the fact remains that some people find an SPL meter helpful. Hell, even if it's nothing more than wishful thinking, it's cheap ($30) wishful thinking! Personally, I've found that I can get my system adjusted to a point that I like more quickly with some help from a meter than with my ear alone (which means I can be enjoying it sooner), so I use one. Personal preference. YMMV.

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gonk -- Saloon Links | Pre/Pro Comparison Chart | 950 Review

A sound level meter is useful for establishing a baseline level of the main LCR speakers, with the level of the surrounds. A $30 Radio Shack meter is all that is needed - in fact the daily level balance tests on movie dubbing stages is done with this very meter. If you want to make adjustments in the relative levels after that, then do so, knowing that you can always go back to the 'standard' setting. Keep one thing in mind though, and this is a big one; the pink noise tests on consumer DVDs (and the internal pink noise generator in components) is band limited to a narrow range of frequencies. If your surround speakers, say, have much different frequency response than the main LCRs in the range of the pink noise band, then your results will be skewed. Professionally, it is done with full bandwidth pink noise. In the end, some by-ear tweaking will almost certainly be needed.

[This message has been edited by soundhound (edited August 13, 2002).]

Brian: (Let me try to explain it to you.) Because, matching volume levels is a quantitative determination most easily done with an electronic measuring device. If you can design and build a $40 device which will simply tell me qualitatively, which unit I will like best and by how much, it would save me alot of time by not having to carefully listen to a bunch of different components.

Better yet, once you determine what easily measurable quantitative data can define the sound that I prefer qualitatively, then all I'd need to do is read those manufacturer supplied data and determine which unit I'd like best without even listening or measuring them at all.

Then again, this would turn a hobby into simply a buying club.


[This message has been edited by merc (edited August 13, 2002).]

Just a side note! I’m just curious, was anyone else told by the RS guy “you can not return this meter”? Apparently they have a problem with people purchasing SPL meters so they can tell the police exactly how noisy their neighbors are! Then they try to return the meter. I told the salesman I didn’t think that would be a problem.

Sorry, guys. It was just a joke. Back in the hole. I love science when it agrees with me too.


brianca..

PS-- I do use an SPL meter and I did do a blind test between the 950 and 1066. Call me crazy.

Brian: That's great. If you feel the need to do a blind test to convince yourself you heard what you thought you heard, and somewhat remove yourself from any bias you might have, that is a good thing for you. I have no problem with anyone doing a clinical trial for their own verification. It is just that most of the time, IMO, differences between components can be heard, preference can be determined based on those identified differences, and the need for any further verification of what you heard is un-necessary and a waste of time and money. This is expecially true if careful listening helps you determine that the cheaper unit is as good or better than the more expensive ones.

What matters to each of us is that we are happy with our purchases and that, in our mind, they were cost effective ones. How each of us comes to that calm conclusion is irrelevant to anyone else but ourselves.

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Take Care,
merc

I don't consider any time I spend with my theater learning more about the equipment and playing and tweaking to be wasted time. I love every second of it. Other that that, I agree with you completely.


brianca.

Brian: Okay. So on that one point we agree to disagree. I used to tweak alot more, but now I just want to buy a system that I think sounds as good as I can afford, get it set up correctly, and then simply enjoy it. Now, I'd rather spend my time enjoying music and movies with my family.

Merc asked, -"If you do not use an SPL meter or even any type of volume based analysis, how do you know which frequencies are impacted by room nodes-"

You have that a little wrong... I have a custom made test tone disc w/ full range pink noise @ 1Hz per track, plus tracks w/ frequency sweeps in the sub range and full range. The volume based analysis is my listening to these tones and sweeps and hearing any fluctuations (nulls and peaks).

I'm sure you could hear just as easily as I can where exactly where the nulls and peaks are and record what tracks what things happen at (track 54=54Hz for exa.).

The details of the exact db's of the nulls and peaks aren't that important to dealing with them to a great extent, in addition to the SPL meter not being exact enough to tell you those exact details if they were that critical anyway.

My main bass peak was ~69Hz-75Hz. I set my mains to 80Hz (best setting for the mains anyway -a brush of good luck) and then flipped the phase on my sub amp's output.

This cancellation countered that peak really well -flatteing it out. As would a bass e.q (I don't hate bass e.q.'s).
A bass e.q. could be even more exacting, but I find the cost of adding one and filtering the bass signal through it just to get an 'nth' degree of further improvement to be tweakin' overboard.

I also have a lesser peak @ ~150Hz but not much to do about that.
I'm just Not gonna ever add an e.q. into my main's chain. And the problem's fairly small anyway so no big deal.

"-and therefore, how to correct those room problems by using tube traps and other sound absorbing materials? If I remember correctly, you are a huge advocate of correcting the room and not using EQs to correct these room induced problems."

Yes, I very much believe an e.q. can't correct a room problem. I'm esp. against these new 'room e.q.'s that claim to fix your full range of audio by using e.q.+phase shifting ot counter room effects. The probs are that -
1)You can only correct (at the very most) one specific point of the room, making the phase and the e.q. change worse in the rest of the room.
2) So far many have said that these systems kill the detail ('life') of the audio by so heavily processing it before output.
Why risk it when room treatments treat the room directly and cheaply too.

Bass traps absorb standing waves evenly down to their limits (determined by the inner dia. of the trap). You don't really need to know the exact db's or the exact freq. of your bass peaks
to use them.

They counter whatever standing waves are present. They don't adjust speaker freq. response, or mess with your speakers at all -just the reflections.

Sorta like cleaning a dusty TV screen. You don't need to know the volume of dust present or what elements of the picture the dust most degrades. You simply clean the screen and gain full benefit from doing so.

Placing the bass traps in the corners of the room cuts the standing waves whatever they may be (unless they're below the trap's tuning). From there, if you need to use and e.q. on non-directional bass or to improve your speaker's freq. response, then you'll be in a much better position than trying to use that e.q. to fight strong room modes -a losing battle of apples vs. oranges.

Again, I claim no golden ear, but rather I think most here could do the steps I take to calibrate my system and effectivly calibrate it to end up w/ no lesser 'correctness' than picking amongst the assorted variables that must be chosen when using an SPL meter method.

An SPL meter's only $30-$40 bucks. It'not like I'm saying "$10,000 speakers are a massive rip off" (because secretly I can't possibly afford them). You must see that I only question the methodology and not the tiny amount of money I think it wastes.

I'd ask for everyone to stay civil about this and I'll continue to answer those questioning my ideas and methods.

I think the main reason I first posted was that it seemed like so many found they had their surrounds WAY too high, and sub somewhat too high.
I have no doubt that if my surrounds aren't dead on correct, that they're not more than a db or two off.
I popped in Cast Away where the ocean is washing front to back all around you and find it to be extremely even. I popped in Metallica S&M concert DVD where there are sections with even crowd noise in the mains and rears -again sounding totally even. No way this is very or even slightly incorrect.

As for sub level.
Look at a site like SVS where they rec. using an SPL meter, but only to get a general point and then rec. you tweak by ear to what level you'd like it to be (+/- several db above your mains/surrounds). And Cd's / DVD's vary so much there is no one perfect setting to match to.

Play a CD with no weak bass on the kick drum, then bottom out your sub on the THX intro on Phantom Menace. The sub level set w/ an SPL meter and not changed either time. I 've never done this, but I know people who have from online.

Matthew,
just for you I'm posting twice again! heh. I don't see anyone's post number on my screen (but don't care anyway). Do you have to look it up or what?
And for the sheer volume I write, would you really only give me 'half credit' for my 2 posts in a row?
I certainly wouldn't mind if Outlaw decided to 'dock my post count' though. -heh
I think it's easier to answer a few diff. people in sepp. posts is all.

Anyway... I think your situation of many more speakers than I have in an asymetrical arrangement (though I think your varied speaker wire lengths are effecting nothing on your levels) is just the sort of thing I mentioned (it seemed to be more like Lena's set up too).

Probably very good for you to use an SPL meter to help you even them up. Did you sit dead center and try it by ear though just to see how close you could get it to sounding even? I'd think you could do this very well (not incl. the sub level -a whole 'nother beast).

I question if you held the meter up, forward, or turned at each speaker. 950 test tones, or DVD players?
You could do Any method and (not to be rude -honestly) call it 'correct' SPL metering as have many here (and not questioning eachother).
Though you should get slightly diff. results. And which result's 'correct'?

Most seem to rec. using the DVD player (w/ V.E. or Avia) over the 950's test tones which makes the most sense to me, and I'm guessing that's what you did. And most seem to rec.the meter 'pointed up' 'cuz it's omnidirectional.
1) It's not omnidirectional
2) your ears most certanily ain't omnidirectional
so I'd have to disagree with 'up' and figure 'pointed forward' would be closer to how you hear (but that's still just a 'kinda-sorta' thing).
Your ears hear diff. behind you making an SPL matching surround tonally diff. than an identical main speaker.
It's more than debatable that you might tick the surround down or up to level match a partial bandwidth rather than full bandwidth that would never match.

This all gets very 'tweaky' though, but these are some of the details I've thought about and took into consideration when I calibrated my set up. Some who've used an SPL meter may have never even thought about all the variables that do exist.

As for a Phantom Center -first I'll adress Mix's answer
-"If you are piloting a land yacht of a rear projection unit, there's no place to put the center speaker. That's why, no matter what Az says, he doesn't use one. (IMO)And yes, it's Monday after a useless post by the Outlaws."

My mains are 3' in front of the face of my RPTV (as I've already described here). This makes it more than possible for me to place a center speaker on top of or below my screen (below being better) and keep all speakers equidistant like they should be (a curved plane).

LOTS (probably ~99% I'd guess) of people w/ RPTVs have no problems placing a center speaker in thier system. Ask around Mix.

Newform doesn't make a center speaker, but...
1) they're going to be making small monitors that could be used as such
2) I could fit a single Newfrom R630 speaker under the screen aimed up slightly if I raised my TV up a few inches (easy to do if I chose to).
3) Lots of people use a diff. brand center speaker that they find to closely match as I could do too

In short (too late!), Mix is wrong.

Here's what I posted recently on AVS when someone asked about Phantom centers...

"I personally use a phantom center (~2years now) w/ my Newform Research (45" ribbon/30" cone driver cabinet hybrid) speakers -having used a few diff. center/main speakers in the past.

I have a 7.1 pre/pro yet I find I have a solid surroundfield w/ a 4.1 set up. I'd argure that more speakers doesn't always = better sound. On a sidenote I'm against bi/dipole speakers in mains or surrounds. (That 'splatter' diffuse sound all other the place)

Your Rec. or Pre/Pro will downmix DD or DTS into a phantom center losing none of the information, so no compromise in that respect.

How well it works for you is dependant on a ton of variables though.

You'll hear people say "comb filtering" is a flaw in the method, but I think that the issue doesn't prove to be any problem in actual use. There's no blatant null or peak in my phantom center and it's far more open, clear and realistic than any previous actual center I've used or heard in dedicated hi-fi shop rooms.

The issue of how far off center you can sit w/ a phantom center is also dependant on speaker placement/type, openess, seating distance, etc... In other words..... it depends.

In my system I can sit fairly off center (~10' away from speakers, 13' from RPTV) and the phantom center still works VERY well. Further off center and it does pull somewhat (not in extreme at all) to whichever main speaker I'm closer too, BUT then the screen is on a distorted angle anyway so the sound still matches the screen, and the surrounds will pull to the side you're on no matter what, so you're just sitting in a 'poor' seat center or not.

I always watch movies w/ my wife, so neither of us are ever dead center and I'll never go back to a center speaker. (not to mention the speaker/amp cost savings bonus).

Diff. speaker designs work better than others, (line sources seem to work the best), but I have gotten a great phantom center out of a pair of $220 Axiom bookshelf speakers too.

A phantom center has certainly served 2-chan. audiophiles for decades. Many multi chan. hi-res audio engineers choose to not include a center chan in the mix. A phantom center is no crime, and I find it to sound better, and not in anyway a compromise or short-cut set up.

Proper main speaker placement is even more critical than in a 3 chan. front end -where often the center chan. is used as a 'gap filler' for mains that are too far apart.

Ever hear people say "I like my HT for movies, but it stinks for CD's"? Probably not the only issue, but mains too far apart is probably ONE of the reasons.

Too far apart (more than ~7-8') and you begin too turn what could be a sharp imaging phantom center turn into a dull 'cloud' of sound. Plop in a center and they say "WOW, it's so much sharper and locked to the screen". And it is, just for the wrong reasons.

If your screen is a 32" TV an actual center will probably be better... since it's good to lock much of that sound to the small screen area (since the center is often mixed as the prominent front speaker than mixed evenly w/ the mains. I mean "panning-wise" NOT "level-wise").

With a larger big screen or front proj. you might find (like I do) that the solid sheet of a front soundstage to be much more open and follow the screen action better/more dynamically/fluidly.

A phantom center is an inherently "perfect" matching center too.

There's just such a compromise to most centers that are called 'matching' (IMO) when they clearly aren't -mainly in that they're usually in a horizontal array for the sole reason that they've got to be able to fit on top of or below a TV. If a horizontal array was of any sonic benefit, you'd see more than the zero number of horizontal main speakers on the market.

They throw more sound vertically than horizontally making them exactly as 'unopen' sounding as a vertical M-T-M array main speaker sounds 'open'.

Most people use center speakers so if it sounds like I'm really pushing a phantom center, it's only because very few other people do.

It may be better for you, maybe not. I think it doesn't hurt for you to spend a good amount of time (and zero dollars) trying to get a tight, solid sharp imaging phantom center -if only for the sake of your CDs being improved by it.

Pull your mains away from the walls as much as possible and don't spread them too far apart. I just laugh when I see someone w/ mains 12' apart and highly towed in."


Matthew, have you tried a Phantom center? It will obviously sound diff. than using your actual center, but you should be able to get as tight/sharp imaging from it, and if you play something with L/R panning (like a car driving across the screen or something like that) I think you'll find the phantom center to give you 'perfect' panning unlike w/ your actual center where you'll hear the 'unopeness' of the speaker pointing itself out -distractingly so once you listen for it.

When you listen to something panning across the three mian speakers does it sound like one solid soundfield or can you point to the left, center, or right speaker at any time knowing exactly where the sound is coming from? Maybe somewhere in-between?

In my system the front stage it almost (though not 100%) disconnected from the main speakers.
If I had an acoustic curtain in front of it, you'd never guess there was no center speaker -most likely just 'assuming' I must have one, but if I actually had a center speaker, you'd know for sure I had one as it (by it's design) points itself out.

I've heard HT's from Linn, B&W, Revel, Martin-Logan, etc... and never heard a center that didn't point itself out or that I liked (and I like the mains from all those companies) better than when the same company's mains were well set up and disappeared.