I'm replying just to keep you talking now. grin Excellent information Boom.

When you say reducing peak frequency are you meaning bumps in the in room response? (like 20db spikes or so?). I know one method is to reduce the ouptut at those peaks to reduce the significance if the null vs the mean. But increasing the sub gain to compensate usually just reinforces the null.

My fascination is how the standing frequency, the one responsible for the massive null in most rooms, is handled. This is dimension and placement dependant. No matter how much power you apply to a standing frequency the null will never be filled. This is why I speculate it must be masked out and replaced by some blending of harmonics and perhaps time (phase) shifting.

At both AVS and Hometheatershack, they have tested and shown before and after graphs. Quite impressive. The fellow behind REW ran some tests and it seems like a very good sub "set it and forget it" device. When he's impressed, its the real deal. smile