2 SVS PB-12NSD vs 1 PB12 Plus

Depends. A pair of PB12-NSDs could potentially deliver smoother response over many seats thanks to modal averaging. I believe the dual NSDs would also deliver slightly more output than the single Plus, although that can vary in the real world. Conversely, the single plus can be tuned deeper if that's your cup of tea. Moving into the non-sonic items, would you rather move two ~60 pound boxes around or a single 125 pound box? Do you prefer two plain jane boxes or a single bigger but more attractive box?

I think you're definitely better off with two NSDs, provided that you locate and calibrate them well. To my mind this means locating them equidistant to the MLP because you don't have any hardware to set different distances for your two subs.

There's an extension advantage that the Plus affords over the NSD, but I suspect (and the crew at SVSound have confirmed) that this extension advantage is easily outdone by the frequency response advantage of having two or more subs. Me, I'm about to add a second NSD to my own room; I was considering either a factory return-upgrade or repurposing my NSD to a different room, but the SVSound folks made a credible case that doubling up on NSDs would be a better move.

Having enjoyed a BASH-equipped PB12-NSD in my ~3,250 cu.ft basement HT space, I think duals would provide terrific output in your ~3,300 cu.ft. room, as well as smoother FR than a single sub.

That being said, the PB12-Plus is more powerful and more flexible overall than the PB12-NSD. Either way (dual NSDs or a single Plus), you really can't lose.

ALWAYS go with dual identical subwoofers in any HT setup.
You'll get smoother bass response in your room.
Going with a single sub is always a bad idea.

I'am rocking with four subwoofers in my HT, two of which are SVS PB12-NSD's.
Audyssey, with MultEQ XT32 and Sub EQ HT, did a superb job in calibrating my subs.

After calibration, I sampled the train wreck scene, from the movie Super 8 on BD.
I fully expected, that all the windows in my place and my neighbors, would shatter at any moment!

WARNING
SECURE ALL LOOSE ITEMS ON SHELVES IN YOUR HOUSE BEFORE THE TRAIN WRECK SCENE
Edited by coolcat4843 - 8/10/12 at 1:24pm

Hahaha. I came to AVSForum for the info, but I stayed for the passion.

Xt? Not really. You will need a y adapter. But it will be fine. I could be wrong, but having the subs ~equidistant from lp if room is pretty much symmetrical by design and furniture might help best. But there are lots of other factors. If a receiver upgrade is in the cards look for one with Xt32, dual sub outputs and sub eq if possible.

butter and jelly please.

Multi EQ XT32 with Sub EQ (Denon 4311, Onkyo 3009,5009) pings each subwoofer separately and sets delay, phase and level and then does a second sweep together after it sets them separate. XT does about the same but only calibrates the two subs as one it doesn't ping them separately. XT also doesn't have as many filters or resolution at XT32.

XT can still do a good job of eqing dual subs.