I have a 990/7500, Axiom speakers (M80's-main, VP150-center, QS8-surrounds), and an Outlaw LFM-1 EX sub. I have an analog SPL meter from radio shack and I need some help. I think I must have done something wrong.

I set the volume on the 990 to 0dB and used the manual test tone option from the menu. I calibrated all the speakers to 75dB, but nearly all of my trim levels are set anywhere between -9 and -13dB, which doesn't seem right. I had to turn the sub trim level down to -15dB (it's lowest setting) just to get it to 80dB.

Does this seem right? Any suggestions for what I've done wrong? Might it have to do with the sensitivity rating of the speakers (which I don't know off the top of my head and, to be honest, what that really means anyway)? Also, should the surrounds be calibrated at 75dB as well?

On a related topic, any suggestions for crossover frequencies? I think I have the M80's set for 80Hz, the center at 120Hz, and the surrounds at 100Hz.

Any help would be appreciated.

Is the meter set for "slow" and "C-weighted"? Those are the two settings that aren't mentioned which could influence calibration. If it isn't set to those, it should be.

The M80's appear to be relatively efficient speakers (95dB in-room, 91dB anechoic), and if your room is small to medium sized it may be even easier on the speaker. The VP150 center and QS8 surrounds have the same efficiency numbers. You are also running a 7500, and I'm guessing that you're connected with balanced cables (yielding a slight increase in the level of the output signal over an unbalanced connection). That could go a long way to explaining why you are able to turn the trims down by as much as 10dB to get down to a reference level calibration. As for the sub trim, check the volume control knob on the sub itself and make sure it's not past about half-way before doing any re-calibration. You may need to dial the sub's internal amp down a bit.

What I might do in your case is calibrate for a higher reference level. In other words, do one of two things: leave the volume at 0dB and calibrate to 65dB, or turn the volume down to -10dB and calibrate to 75dB. The main goal of calibration will be achieved (all channels will be playing at the same level relative to each other), but you will typically have your volume set to a position about 10dB lower than someone else might. This will do no harm.

As for crossovers, your speakers' individual "-3dB" points are as follows:
M80 = 34Hz
VP150 = 85Hz
QS8 = 95Hz
Based on those numbers, I might actually swap your center and surround settings (go to 100Hz for center and 120Hz for surrounds) or possibly set both to 120Hz. You could probably try the M80's at 60Hz and see how you like them there.

I don't think your settings are off. I set for 80 db. I don't have Axioms but my settings are this.

FL - -9
C - -2
FR - -9
BR - 0
BL - -10
Sub - -8

(large difference in the rears is due to location relative to the sweet spot)

My fronts, center and rears are at 32Hz close to your M80's. I found I like them set at 80Hz for the crossover.

Oh and gonk are you sure about the "fast" setting. I've always heard you should use "slow" and C that is what I have been using. I'm not sure what the "fast" and "slow" refer to.

You're right, mzpro5 - it should be "slow" - not "fast." Editing previous post to fix the error...

Fredneck,
gonk is on top of it ... we would expect nothing less from him!!!!

Just turn down your volume. try -5 or -10 at 75db. This is what i do.

you should be golden.....

Thank you everyone

Oops, accidently sent the last reply before I finished. I'm glad to read I'm not necessarily doing anything wrong with the trim levels.

gonk, I did have the meter set on "C" and "slow." I'll have to play around with the sub setting.

One last question...should the surrounds also be calibrated to play at the same level as the front and center speakers?

Yes they should all read the same. Your source material or mode will decide what you hear from the surrounds.

I'm gonna have to give that a try and see how I like it.

As mzpro5 points out, all channels should be calibrated to the same level - that's why we are using the SPL meter in the first place.

Thanks gonk and all that responded, and to respond to a part of gonk's first response, yes, I am using balanced cables.

I can't wait to try this out!

Just wanted report I calibrated my speakers over the weekend and I am just flabergasted by the sound...my system sounds so sweet!

I ended up turning the volume down on the 990 to -10 and calibrated to 75db at that setting. It worked great. All of my trim levels are between -3 and +1. I do feel like I'm running my sub a bit hot though (Outlaw LFM-1 EX). The volume on the sub is at about 10 o'clock and the trim level is +1, but the db at -10 on the 990 is about 90db.

I admit I like a lot of bass, which is really a matter of taste, but 90db seems a bit hot. I'm thinking it is most likely a matter of sub placement. I'd like to move it around to see if I can get the calibration and sound a little more balanced, but my current sub cable is too short to move it anywhere. I'm planning to buy a longer cable, but can anyone tell me what the recommended max length of a sub cable would be?

Once I get the new cable, I plan to place the sub in my favorite listening position and do the "sub crawl." I told my wife that the other night when we were enjoying a few beers and she laughed so hard she spit her beer all over the coffee table. Luckily, my remotes were next to me on the couch. She told me I'm turning into such a geek, which I take as a compliment!

Also, gonk, I tried the crossover settings you recommended for my Axiom speakers (60 for the mains, 100 for the center, and 120 for the surrounds) and man does it sound great. The difference is most evident in the M80's. I forgot just how much these speakers can handle and now that I lowered the crossover frequency, they really shine. I was listening to some music in stereo mode last night and I fell in love with my system all over again.

Sub cable length shouldn't be an issue - get what you need to put the sub where you need it, and be sure to avoid running it in parallel with the power cord (close proximity to 120VAC could yield a "hum" from the sub).

Keep in mind also that the standard Radio Shack SPL meter is not perfectly accurate at low frequencies. There's a correction chart out there somewhere to compensate for that, and if you haven't done so already you may be running hotter than you think. It's just something to think about. Once you get the sub into its final place, you might want to experiment some more with the trim settings.

Glad to hear that the new crossover settings are working well for you!

Thanks gonk. I'll have to see if I can find that correction chart to compensate for the SPL meter's deficiencies at low frequencies. When you say I might be running hotter than I think, is that necessarily a bad thing? I mean, doesn't it really boil down to setting the speakers (sub included) to a level that sounds best to me? Is there any harm with the sub running too hot?

Fredneck

Here is a link to the correction table.

Correction Table

Thanks mzpro5. Perhaps you can help me decipher what those corrections actually boil down to when I'm calibrating my sub. Specifically, when I calibrated my speakers, I set the volume on the 990 at -10 and set all the speakers to 75db from that reference point. The trouble I'm having is with the sub. I'm at work right now, so I don't have all my trim levels available, but if I recall correctly, most of them were set between -4 to +1. I set my sub up to my liking at +1 trim level and the volume on the sub itself is at about the 10 o'clock position. I like a lot of bass, but at this level, the db for the sub output is coming in around 90db (with the radio shack meter). Based on the chart you provided, how should I be measuring/calibrating this?

In the end, it is your ears (and your satisfaction with the overall sound reaching those ears) that matter the most, but calibration by ear alone is almost impossible (I've tried it, as have others, and it's inevitable disappointing) and subwoofer/speaker integration is a tricky matter. I'd at least try running the system with a lower trim setting on the sub to at least have something to compare to.

I'm curious what the meter readings would have been if you had moved the sub channel's trim down to around -10dB (and if you then liked the resulting sound when listening to movies and music).

I did try that at first. In fact, when I turn the trim down to around -10, the SPL meter reads around 75 db. However, the difference is very noticable...to wit, almost non-existance of bass. Perhaps that is what it should sound like, but I like to hear and feel the bass. Now, the other issue involved here is probably the sub placement. I'm going to order a 30 or 40' cable from blue jeans cable so I can really experiment with the sub's placement. I'm thinking my primary listening/viewing spot is right in the middle bass dead spot.

I'll have to say that my sub trim/setting is where I rely on my "subjective analysis". I will use the meter for the sub but always end up tweaking it to my personal preference. In fact I will alter the trim via the sub's controls for different media. I realize the practice probably wouldn't be considered "professional" but it's what I like. And I have a tendency to run a bit hot according to the meter, especially with movies (like the floor to shake

What are you listening to when you have that "non-existance"? For a lot of music, there should be almost no subwoofer output with a 60Hz or 80Hz crossover - very few instruments play that low. Tweaking the sub trim to get that distinct subwoofer contribution from source material where there is minimal content means you are exaggerating the lowest octave bands significantly.

SVS still has a long list of good subwoofer demo material in their FAQ (specifically here ), as do many assorted online forums (the "good subwoofer demo" debate is a common one, after all). I'd start with some of these, as they are specific examples of a source that should be placing strong demands on your sub. Running 11dB hot may make those scenes feel very "muddy" - sacrificing audio details at higher frequencies by drowning them in low end roar. You may still find that you prefer to run your sub hotter than calibration alone would suggest, in which case you will know that you've found the right setting for your needs, but my suspicion (without having heard your system, of course) is that you may be happier with the results if you give the system a chance at a more balanced sub output.