I wouldn't be so adamant on finding the answer to this If I hadn't heard what audyssey eq could do to improve my bass response in my bedroom setup. I am now an adamant supporter of room correction know if done for the bass frequencies because of this experience. It was not an easy integration with 3 full range towers and a sub. But Audyssey nailed it. You know I wasnt always like that PENG. In fact I was completely against any room eq at all. And audyssey multisub eq is done with 2 sub inputs wired independently on the Denon. This is done for a reason. Otherwise they'd just wire it parallel. Now Arcam is offering a prepro for over $5000 that does this same improvement on bass. For up to 4 subs. But it needs to be wired the same way Denon wires they're sub outputs for it be 100% effective.\n\nAudio Advice contacted me today and is going to check with they're installers of the Arcam units to find out the answer to this question. They said they will contact me back Monday I will keep you gentleman informed of what I find out\n\n\nI think we (even ADTG) are in general agreement that RC\/REQ are effective in the 10 to 300 Hz range, above that it becomes "it depends.....". My point is, as ADTG explained clearer than I could, that to time align each sub vs grouping identical ones that are equidistance is an overkill, and to EQ them individually is not necessary, may even do more harm than good when there is only 1 sub channel. DLBC may be perfect in this sense and can actually do good in the independently aligning and EQ'ing each subs up to 4 or more without grouping them but even then, is the effect audible, that's the question? That's why I rarely say I am running 7.5.4 just because I have 5 subs in my set up, because it really is just 7.1.4 even if I have 8 subs.:D\n\nAs I said I would likely purchase DLBC when it becomes available (for my simple 2.1 system) I won't tell others if they do that they will hear improved sound quality. I do those things because I am very curious about those things, and I can afford some of those things..:) But then I don't have golden ears, so ommv.