Shadorne's comment re: "sealed subs only" is probably, as a practical matter, good advice for a music only system, but it may be a bit of an overstatement. The SVS subs he mentions shouldn't be dismissed. Their top model, in it's fully ported configuration, outperforms most sealed boxes on group delay tests. This test usually favors sealed, highly damped designs - but the SVS Ultra shows awfully well. Also, like all ported subs, it offers more deep, clean output capability than a typical sealed box design of similar size and amp power.
That latter item may not be critical for most music (how much musical program material has deep bass info <30hz, anyway?), but it begs a question:
How do you intend to install the subs?
If you're going to roll off the bass to your mains and cross at or above 60ish hz, I'd say sealed boxes are safer bets. If you're gonna run the main speakers full range and "snug up" a sub below their natural roll-off, then it becomes a more open question. Many users on this forum run their subs in this fashion, often rolling off their sub's upper response somewhere below 50hz. In this configuration, a ported box (particularly a good one like the SVS seems to be) may make more sense.
Good Luck
Marty
