Axiom Home Page Forums General Discussion Home Theater Speaker configuration with SPL meter--or not

Just this week, I received my new Axioms: M22s, VP100, and QS4s. They sound great. They are coupled with a HSU STF-2 and an H/K 230.

Even after reading lots of posts in the forums about calibration, I'm still somewhat confused. The H/K has a mic for calibration built into the remote. I did what the manual suggested: set the volume to -15dB and let the receiver do it's thing. Strange result: all five speakers were set to +10dB. This doesn't make any sense--it simply made everything sound louder at the same number on the receiver display. (Reminds me of Spinal Tap--"But our amplifiers go to 11").

So, I went to Radio Shack and bought the analog SPL for $40. At the levels I want to listen at, I can hardly get the SPL to register. I guess I have to crank the receiver way, way up to get 75dB on the SPL. But, it seems like I should configure at the volume I plan to listen at--unless the entire system (receiver and speakers) is linear over volume.

BTW, the receiver generates test tones and my Finding Nemo DVD has a THX setup menu as well. I will grab the "Home Theater Tune Up by Sound and Vison" DVD at my next opportunity.

Any advice?

BTW, all of my speakers are set to small, and the cross-over on the sub is switched out.

basically what your doing with the meter is setting a baseline where all you speakers are outputting the same spl. Yes you will probably set the level higher then what you will normally listen to music/movies at. But what your doing is caliberating it so when you listening at normal levels, all your speakers are putting out the same spl. So your caliberating the speakers at this level to get the same spl, at any volumne

Metier

Rjones, glad your speakers sound great. I formerly had M22s and STF-2; they are a great combination.

I don't know how the H/K cal system works. It putting all five speakers at +10db doesn't seem right. My Yamaha RX-V1400 automatically adjusts tone volume during calibration, since some speakers are much more efficient than others. You seem to describe a semi-automatic procedure where you manually set the volume, then the calibration mic takes measurements. I can't see how this would work consistently, since -15db receiver volume on some speakers would be drastically different loudness than others with different efficiency.

Getting the meter was a good idea. 75db pink noise calibration tones on the "C" scale isn't severely loud, nor should it require cranking your receiver way, way, up.

For music, I often listen at about 75db, which to my taste is "comfortably loud". 85db is very loud, and I only listen for short periods at that level.

Are you sure you used the meter properly? For calibration with tones, set it to "C" weighting, slow, and the scale to 70db. If your goal is calibrating to 70db loudness, the meter should read 0db when 70db SPL is present. For 75db, it should read +5, or you can switch to 80db scan and it would read -5.

For measuring music loudness it's sometimes useful to try "fast", not "slow", to see transients.

In general using a calibration DVD is better than receiver test tones, since that uses the entire playback chain. However receiver test tones plus a Radio Shack meter are a lot better than nothing.

It's possible your calibration mic didn't get the loudness it expected, so boosted all speakers +10db trying to compensate. Usually the max boost is 10db, so this may have swamped any attempt to set varying levels for calibration. I'd suggest re-checking your manual, trying it a few more times, contact the receiver mfg for any tech notes or support forums. If that doesn't work, just use the RS meter and manually calibrate to 70 or 75db, whichever you're most comfortable with. The main goal is getting relative loudness set properly between all the speakers and the sub.