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.