I have my PB12-ISD in the corner of my living room sitting next to the right main speaker and resting on a hard wood floor. I purchased it in January and kept it about 4" from both walls for around 2 months and it sounded great. Last week, I decided to play with placement a little and over the course of an hour or so ended up with the sub at 9" from the front wall and 6" from the side wall. With the new placement, the sub tightened up a little. During my experimentation, I listend to DVD's and CD's. I started out with DVD's but did not notice any difference between the different placements I tried (I was moving the sub out from the wall about an inch at a time). However, once I switched to music, I was able to hear the difference. I suspect the difference was there on DVD's also, but maybe it was easier for me to hear when listening to music.