Why is it that once I perform a calibration on my Onkyo 875 that the maximum volume has been limited. Before the Audyssey calibration it was not limited but now the receiver will only go up to about -8db whereas the maximum volume goes up to +18db. Most of the time I find that -8db is enough but sometimes the input source is low and I need to extra power in the receiver.

Drew, if you really mean that there's a difference of 26 on the volume scale, that's very unusual. Whenever a calibration is done, whether it's manual or auto, the maximum volume setting possible is reduced by the same amount that the level on the trim setting in the receiver was increased. For example, on one of my receivers the adjustment on one channel was +4 and this resulted in the maximum +79 volume setting possible being reduced to +75. There's no actual difference in the maximum volume possible since +4 on the trim setting and +75 in the regular volume scale still results in the original +79 maximum setting. Your numbers are far outside the adjustment limits.

John, What do you mean when you say "on one of my receivers the adjustment on one channel was +4...". What do you mean by channel? Is this one of your speaker outputs? So this means if my rear speakers have a gain of 15 db and the fronts have a gain of 0 db then I will lose 15db of output from the front even if I switch the listening mode to stereo?

Drew, in the particular case that I mentioned it's the left surround that was calibrated at +4. If I set the receiver to show no surrounds the +4 adjustment isn't relevant. The +2 calibration on the right front speaker becomes the controlling factor and the maximum setting on the volume control is now 77.

Again though, if you're seeing a difference of 26 on the maximum volume setting, this can't be explained by the calibration adjustments. They can't be that big.

The funny thing is that my fronts are set to the highest value and this is -3.5db, so this should if anything increase the maximum volume. I should point out that the maximum setting on my volume control does not decrease. It always has a maximum of +18db regardless of what the channel gains are set to. The problem is that once I reach -8db maximum output is achieved. Increasing the output beyond -8db has no effect upon the output from the speakers. This is very frustrating.

Interesting (to me) that -3.5 dB is your highest set trim. With my Denon 1909 with old 90dB sens. bookshelf spkrs all (7.1) around (except in-wall sides), my max trims were fronts and sides 6+ - 7+. When I got my new (95dB) M80s they showed +7.0 & +7.5. I had assumed the better sensitivity would lower the trims.

Of course the trim levels don't really matter, but I am curious what factors do affect trim levels? Now I am guessing it may be room size and acoustic properties. It would be interesting to understand what affects trim levels. My room is 31'L x 23'W, with Aud. mic 12' from front speakers.

Drewy, do you have a smaller fully enclosed listening room?

Is it just the number that concerns you or is it actually quieter? Have you measured with an SPL meter?

For each speaker, list the trims that were set after running Audyssey. Also describe how you ran Audyssey setup (how many positions, did you use a tripod, etc.).

My Denon has a "maximum volume" setting that has nothing to do with Audyssey. Are you sure you didn't accidentially change something like that? You might post a question on the AVSforum to the master Audyssey thread.

When I run Audyssey it sets my M80's channel levels to +7.0 and +7.5. But if I use my RS SPL meter to set them manually at 75db I get +3.0 for both. This hold true for all my other channel trims also, about 2.5 times higher with Audyssey.

Might Audyssey trims set by two different brand (or even model?) AVRs in the same room differ (with mic. pos. and all else unchanged)?

Drewy, what brand/model AVR do you have?

I've never seen my 3808 or 2805 set the trims that high, I suppose it will vary from room to room. I think my 2805 went up to +20dB on the main dial, so even if the 80's were set to +12 for the trim level, it would still go upto +8db when cranked.

My Onkyo has an option to set the maximum volume electronically within the settings (likely to keep little kids or teens from cranking the volume to 100% and blowing the receiver). Audyssey may have turned this option on when the default is normally off.

Welcome to the world of "Odd"yssey.

Check your Onkyo manual for this option. You should be able to turn it off again.

Randy, you have a very large room. What does Audyssey on your NEW 3808 set all your speaker trims at? I know you know them by heart!

Audyssey changes distance and trims and set the EQ option. It ignores everything else.

OK I found the problem. I discovered that the tone control settings were set to +12db for bass and treble and I also have an intelligent volume control which enables the user to increase the signal volume if it is low. This intelligent volume setting was set to +12db as well. After returning both tone controls and intelligent volume to 0db I was able to get volume up to +18 db. Thanks for everyones help.
I also noticed with that with Audyssey cal. that my fronts are set to full range even though I have a subwoofer. I understand that this is probably correct as the frequency response of the M80's is within +/- 3db below 40 hz. I would have thought that it would be best to set the crossover for the fronts around 80hz so that the sub could do a bit more work. What have other people here done with this setting? I know that this will vary according to the room specifications.

Did "Odd"yssey change the tone control and intelligent volume settings to +12? How did they get that high?

No Audyssey didn't change these settings. I must have done it before the Audyssey calibration.

drewy, Audyssey does not set the speakers to small or large, it looks for the -3dB point for each speaker, and reports that back to the bass management for each manufacturer. Denon is now using 40hz, as the determination of making a speaker large or small. Audyssey company recommended that to Denon, and they followed suit. Some other manufacturers like Marantz still use 80hz.

In either case, the folks at Audyssey recommend to change those speakers found as large by the receiver, to the small setting. Also, you should adjust the crossover up from 40hz to 60 or 80 on the Axiom m80's. This is all spelled out in the documentation help guide, or in the Audyssey thread over at AVS.

Dave, here is what I have so far for trim levels.

Left M80 -3dB
Right M80 -2.5dB (Large/40hz cross, changed to small/80hz)
Center -2.5dB (Large/40hz cross, changed to small/80hz)
Sub(s) -2.5dB (need to figure out why distance is 27ft now)
Surround R +2.5dB (90hz crossover)
Surround RB +.5dB (90hz crossover)
Surround LB +1dB (90hz crossover)
Surround L 0dB (90hz crossover)

Yeah, Drew; what you later "pointed out" wasn't apparent from your first post, and it was thought that you meant that the volume number couldn't go above -8. As it turned out, this had nothing to do with the calibration, by Audyssey or otherwise. Good that you found the "intelligent volume" setting problem.

Yes, although Audyssey set the fronts to full range because the measurement showed that they were able to reach low enough, it's still a good idea to give the sub more work in the frequency range that it does best and take some of the lowest bass load off the M80s. Manually set the M80s to an 80Hz crossover.

John, as I mentioned, Audyssey does not set speakers to large or small, it looks for the -3dB point of each speaker in your room and reports that to the bass management of each manufacturer. Denon uses 40hz now to determine small/large, whereas Marantz is still using 80hz. Not sure about Onkyo or NAD.

Audyssey also recommends setting speakers to small as the resolution filters they apply work better for the sub to handle, as you mentioned.