Dual subs and room size

Hi. I've been considering dual subs with speaker input to pair with my Martin Logan 35xt's and not sure what I should be considering in relation to room size. My room is 17' X 10' with the equip along the long wall. I've been looking at SVS sb1000s and HSU vtf 1/3. The SVS are 12" sealed vs 10" ported hybrid for the HSU. It was suggested that I go with no more than 10".  They will support 100% music. The speakers are pretty much an 9' equidistant triangle set up and would be looking to set the subs on the outer side of the standmounts. Any thoughts or advice would be greatly appreciated. Thanks, Dave

The number of subs has little to do with room size or volume. You want multiple subs to get a flat response by canceling room modes. (Two minimum and three preferred.) Read the stuff by Geddes. It is pretty well established science. Use attenuation to address volume to taste after you are flat.
Yes, two subs is better, but 1 sub with acoustic treatment and eq is very very good. My point was, for a room that small, 1 sub is probably enough. So much so that the second sub may not be worth the expense.

Buy a dozen subs if you want to but if budgets and floor space matters, and I'm not ashamed to admit they do to me, then starting off with 1 sub, with bass traps and EQ may be perfect.

Personally, I would take 1 sub with room treatment and EQ than 2 subs without any day of the week. I can get damn close to perfect. So much so I no longer care about the difference, and while I may merely reduce the worst nulls, my overall response will be much closer to flat, or my version of it than having 2 subs, no matter how well placed.

But again, the buyer should make themselves happy.


I have a pair of Hsu subs with EQ, and my office is smaller than the OP's room.
I think erik is correct, the OP would probably be very satisfied with only one sub. 
Again, assuming your quest is a flat FR and not just volume I disagree. EQ can't fix nodes only constructive modes (antinodes). You will be happier with two half price subs versus one full price subs all else held constant if your goal is flat FR. If you just care about volume one sub in the corner of that size room will rock your world unless you sit in a node.

Alone EQ's use with a sub is limited to reducing the worst peaks,  however with bass traps in place it gets much more effective.

I've tested this and there's online explanations for this. Bass traps de-energize the ringing, allowing EQ's to work better, and by reducing the peaks, you can actually reduce the decay rate. It's pretty awesome.

You also get to moderately fill in the nulls. Not perfectly, mind you, but damn better. :)

2 subs assymetrically placed are better, but again, 1 sub + traps + EQ is pretty remarkable, and my suggested STARTING point for anyone.