Standing waves are low frequency sounds that tend to "pile up" in a room because of its parallel surfaces (ceiling to floor, and opposing walls). Pioneer includes a feature to find the three largest bass peeks and attenuate (cut) them down.

EDIT: If you happen to have a room where two or more of the parallel surfaces are equidistant, you're really screwed. smile

Last edited by ClubNeon; 01/26/11 08:21 PM.
Pioneer PDP-5020FD, Marantz SR6011
Axiom M5HP, VP160HP, QS8
Sony PS4, surround backs
-Chris