I finally got around to purchasing a Y cable, busting out my Rat Shack SPL meter & Rives test tones. I thought I'd post my "post purchase" impressions.
1) Hsu's "down to 25 hz" sub is very different that Infinity's "down to 27 hz" sub. The folks on this board that push Hsu are doing people a favor.
2) I've got it hooked up with a Y connector to my sub out, but if you don't have a splitter, hooking a second sub up through your main LR works pretty good too. My Denon receiver has a setting that will send LFE to both the sub and the mains.
3) 5.2 or 7.2 isn't something just for high end systems, everyone should add a second sub - not really everyone, just those that read Audioholics and don't already have more that one sub.
4) My wife helped me put it all in perspective. I was trying to explain the reason for the upgrade & she said "So just now & then it will make a few sounds a bit louder?"
I've been listening to a lot of music the last few nights, enjoying it all over again. A little bit more bottom does make a difference.