quote: "3. Since I don't really understand the +/- dB levels I changed the main volume control to absolute and stored "71" as the max volume level but want to crank it higher. Given the numbers up above, what would you say my max volume should be from 1-100 absolute? I have already blown speakers from over cranking the volume and having my channel levels to high."
my guess at the reason you blew speakers was because you wanted to listen at too high a volume; the amplifier went into clipping, sending too much power to the speakers including some harmonic distortion. whenever your source sounds a little bit distorted and you know the source is clean, it means you're overdriving your amps and it's clipping. this can kill speakers very fast.
muddy and distorted high level sounds is not very nice to hear; the M80's can take a whole lot of clean power and will reproduce sound clearly and cleanly even at very high volume levels. in fact, they can be so loud that you will not be able to stay in the room when blasting away at the full power they can take.
damage to speakers, according to an engineer at QSC, is cumulative.
if, when watching movies, you often need more volume than what you get with a setting of 0.0dB and everything calibrated with Audyssey, that means you should either 1: get a more powerful AVR or 2: use external amplification.
doubling the volume means you need 10 times the power (10 dB more);
going from 125 Watts/channel to 150 Watts/channel is very little difference, not worth the money. you would not hear the difference.
if you decide to get more power, i think you could use a high power amp for the front L and R, and use the Denon amps for the surrounds; the surrounds usually use much less power than the fronts.
of course, if you like to listen at insane levels, then you surely will damage your hearing and you might have difficulty getting the sound levels you want, whatever the amp power you use.
i used to know a musician who, during practice for a rock concert inside a cinema, told the technician that he could barely hear the monitors in front of the stage and he was telling him to get the volume way up.
the tech showed him on the spl meter that the monitors were playing (during his practice cession) at levels of 120 dB SPL.
he had lost most of his hearing for that reason, but he was blaming the weak sound system.
with the M80's, unless you have a very large room, 125 Watts/channel should be ample to get realistic sound levels, most of the time.
here's some numbers that you might find interesting:
in a small to medium room, where you sit at around 2 meters from the front speakers, one of those speakers will put out approximately:
91dB/1 Watt
111dB/100 Watts
112dB/125 Watts
When the 2 front speakers put out the same sound, then add 3 db to all those numbers.
the movie standards say that the max SPL for a movie is 105dB,
and 115 dB for the sub frequencies.
this is a standard for cinemas, as well as for HT.
Most of the time, when watching movies, the average power going to the speakers is less than 1 Watt total, but very loud peaks will demand much more power, maybe some 50 to 100 Watts (with your system) for a short time.
as you can see, you most probably have enough power for realistic levels, unless your room is very large and acoustically very dead .
hope this helps. :-)
Last edited by J. B.; 09/03/11 10:14 PM.
