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.
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.
