Quote Originally Posted by blackraven
True words about room placement! Also, I've notice many people have their subs turned way up which is a matter of taste and possibly ignorance. I tend to keep my sub turned down to the point you barely notice it and then just a hair more when listening to music. For HT use I turn it up.
You should consider tuning your sub with a parametric equalizer sometime. One reason why people have to constantly turn up or down the subwoofer level is because the boomy room-induced peaks dominate what gets heard from the listening position. One moment it will sound anemic, another moment if the bass hits just the right note, your head's ringing.

Once you flatten out the in-room response with an equalizer and eliminate those low frequency peaks (which in a typical room can go +20 db or more), then you can turn the sub level up much higher than before, yet it will still sound very accurate. Do a search for some of the previous threads on parametric equalization and the Behringer Feedback Destroyer in particular if you want to read up on the subject. (search terms "parametric" or "Behringer" should suffice) Posts by Richard Greene and Sir Terrence The Terrible are particularly informative on this subject.