Axiom Home Page Forums General Discussion Home Theater Reference Level

With typical total harmonic distortion levels (claimed levels) for consumer AVR's being about the same, "0" gets uncomfortably close to clipping. At that level, mine so overloads the room that I can't even tell if there IS distortion.

what Audyssey does, when you calibrate, is adjust the gain in all channels so the signal levels at the MLP is 75 dB for each channel individually. I've checked this after calibration with a precision SPL Meter, and the individual channels all play back at 75dB when using the AVR's test tones.
if your room is very large, then Audyssey will want more gain in all the channels so that the sound level at the MLP is 75dB SPL. it demands more power from the amps in order to get this level at the MLP compared to...

if you room is small, then Audyssey will want less gain in all channels so the signal level at the MLP is 75 dB SPL. it demand less power from the amps in order to get this level at the MLP.

Smaller space = less power for the same SPL.

this gain adjustment inside the AVR is like a preamp preset (for every channel) that supplements the master preamp volume control.

this has nothing to do with good or bad sound, only with individual channel levels.

in an uncalibrated system, there is no Reference level, but only Preference level. for someone with a good ear, the two will often coincide. it's more difficult to get right because one has to keep making volume adjusments until the right volume level has been found.

is your sub well calibrated or is it running very "hot"?
do you have some sound treatment or is the room "live"?
a live room will be worse sounding as SPL goes up and at a certain level it will not be listenable (horrible).
are your amps clipping?
are your high frequencies adjusted to "flat" or Cinema?
Are you sure that it's not the sub "pressurizing" the room?

any one of these, or other things, could be the cause of your room "overloading".

i have about 3000 Watts, some of which are used to produce sound levels up to 115 to 117dB SPL in my small room (about 1300 cu.Ft.)and the sound is crystal clear. obviously, only part of those Watts are ever used; the rest is insurance in case i move to a large room someday.

Thanks J.B. I was wondering if that wasn't the case since the first thing that Audyssey does is ask you to manually dial down the sub to 75dB...

You also make the same point that I suspected, that it bumps up or down the channel volumes to compensate for room sizes.

Maybe I'll have to pop in Super 8 tonight. I've been dying to see it and my oldest daughter has been begging to watch it, so it would be a win-win if I can get them to watch it at a louder level.

Bob, I can play "above" 0 and still don't get distortion or clipping. Granted, this is only for short periods of time, but I've tried it.

All great points, JB and Nick. I guess what I'm saying is that I have no pressing desire to "go there," not for a movie, anyway. I'm using 1/2 the total power of JB. I sit about 7 feet from the center, about 9+ feet from the mains (M60/4 QS8/ep500).

For movies, 14-17 does just fine. I listen to most pop/rock music at about 14-16 (2-channel 95% of the time), depending on the recording. It's not that I hear detectable distortion at higher levels, I guess I don't need more to rock my plimsole--- in the house. It just gets assaultive past that point, because we're not talking "peaks," but rather whole tracks at full throttle levels all the way through. It'll never be a rock show, so I'm not really trying to recreate it. Though I DO wish that the sound quality and gain of some classical recordings sounded like the orchestral parts do on blu ray.

Surround is awesome for movies, and merely OK to me for a concert video. SACD is against my R & R philosphy (belief system?). R & R live is a plain ol' 180 degree, full-frontal attack. Timbre and room acoustics don't have much to do with most places I would see live R & R, large or small, certainly not in a club-sized venue. I would love surround for orchestral music or jazz, but I almost never listen to either, because they're too soothing and all the pianissimo parts take too long. I'd rather listen to a ballet than sit through an opera.

By the early 70's, decorum and contemporary music parted ways for good and I didn't let that train leave without me.

It's the same feeling I get when I've got ye olde Snells blasting away in my shop. If I drop something near them and bend down really close to the speaker to pick it up, I almost get nauseous. That's because I'm almost always at about 95 db @ about 6 feet.

I guess there's another factor at play. When I had a Hammond and a Fender Rhodes and an ARP, I could tolerate any volume, as long as those brilliant sounds (obnoxious atrocities) were being gifted to the world (committed) by me. It's amazing how loud you can bear things when the one making the noisefest is one's self. It's the only thing that Blue Cheer got right!

I guess its time to reslut.

Do you mean + or -? I'm listening in the range of -14 to -17 as well. When I checked, reference was at around -12. This is after using audessey for level and distance calibration.

My daughter keeps telling me to turn it down when I get close to -14. She would be much happier at -20.

There is also Absolute volume(82.0)numbers go up until reference level, and Relative (0.0), I prefer absolute because it's closer to decibal and my Onkyo says when ref. level is on(lights up) but I agree....too loud.

On my Pioneer it plays pink noise (your wife would like that) at what is supposed to be 75 dB, you can adjust the individual channels trims so they read that on the meter, then the system is calibrated.

On my old Sony the main, left and right, didn't have trims, the center and surrounds were relative to the mains. So you'd enable the test tone, and turn the volume up until the left channel was producing 75 (or 85) dB. Then you'd cycle to the other channels to adjust them the same. The volume control didn't have a dB scale at all, it was just a big knob. So you'd never know when you were at reference level.

Sorry, Fred, yes, minus 14-17. I have 2 Onks, both w/ audyssey. The 7.1 reads from -82 to +12. The 5.1 starts at 0 and goes up to 82. Cd's also seem to be getting "louder." With new releases by some bands two years ago, I would top out at -14. Now there's new stuff that I can't listen to much above -18.