I have just hooked a Feedback Destroyer Pro into my chain, and I am now flattening out my sub response (with a slight house curve). Here is my question: I have JM Lab Cobalt 816s as my mains. They play down to 40-50 Hz range. My receiver is set to small mains + sub. My crossover occurs at 80 Hz. When THX is applied while using DD or DTS, the crossover is also at 80 Hz. Therefore, when I set the sub with the Feedback Destroyer, I used the small setting plus sub. It sounds great, and is a very seamless blend now. My concern is what happens when I am listening to DVD-A? My universal player (Onkyo DV-SP800) has bass management applied when using SACD, so I would assume it would be close to my original settings. The DVD-A portion of the player does not apply bass management (although it does apply time delays). The question I have is what happens to my bass when I am listening to DVD-A? My sub now has filters holding back certain frequencies to tame peaks, but when the mains are set to large (6 channel analog input with no bass management), what happens? I can't seem to get my head around how it will play out. Will there be doubling up of frequencies, or holes? Or should it go unnoticed? Thanks.