I've already documented my work with optimizing sub placement and EQing to optimize sub response across all listening positions on my main couch in earlier posts: Official SVS Owners/Support Thread.
I've been watching a few movies and shows (Transformers, Transformers Dark of the moon, Gravity, Hunger Games Catching Fire, Super 8 Intro and The Pacific) over the last few days to break in the system and to gauge the audio quality. As my measurements have shown, the single PB12-NSD in a corner actually works quite well at my seating position (which is ~12 ft from the sub). I might be getting some near field benefit since the bass is certainly not as clear or well defined towards the back of the room (kitchen area), but I have to say that the single sub is more than adequate in my setup. Another sub would perhaps help smooth out response across seating spaces (but I have no room for another one) but I don't see it actually helping improve sub response at my sweet spot where I get pretty much flat response all the way to ~19Hz. This is with the gain setting at 12 o' clock position and receiver set to -7dB for the sub channel so I have plenty of head room even with a single sub.
Impressions so far have been simply WOW!
. The 20-40Hz bass really makes such a massive difference to the entire HT experience and the level of immersion when viewing movies. The 40-80Hz bass is nice, and that's what I was hearing/feeling previously with my Dayton sub-1200, but the real difference in immersion does come from the lower frequency content. I was watching an episode from the HBO series "The Pacific" last night and every explosion felt so immersive with very crisp/clear LFE content shaking my room/couch. With the first few explosions, I actually found myself shrinking back into the seat as if to try and get away from the explosions
. The bass also integrates beautifully with my budget setup (3 Infinity Primus P163s for LCR and cheap Logitech Z5500 satellite speakers for surrounds) and there is zero localization issues (Xover on receiver set to 90Hz - 90Hz gave a smoother transition to the speakers than 80Hz as measured by REW).
All-in-all, this has been a very satisfying purchase! I am certainly now a believer and supporter in the bandwagon recommending that a large portion of HT budget be devoted to the subwoofer. I think 4X more expensive speakers would sound nice, but would not add too much to my HT experience over my Primus speakers. But I know for a fact that a 4X increase in sub budget from the Dayton to the PB12 has provided a massive increase in the overall HT experience!
However, all my experimenting has also taught me the real importance of making measurements and spending the time to properly setup a subwoofer in your HT space. I think it is unfortunate that many folks seem to spend big bucks on expensive subs and then just place them in a single position, turn up the gain and run Audyssey/YPAO and call it a day. A sub crawl is certainly a step in the right direction, but even that won't tell you anything about specific room modes resulting in nulls at specific frequencies. For the amount everyone invests in these subs, I think they owe it to themselves to spend a day or two with proper equipment (mic + REW) taking measurements and determining the best subwoofer settings and placement for their seating locations. I have a sneaky suspicion that a subset of folks posting here who didn't bother to spend the time and effort to make measurements could have avoided more expensive/powerful subs or moving to dual subs if they had spent more time optimizing their setup with an existing sub. I know that if I had selected any of the other potential locations for the SVS, I would have been very underwhelmed with overall response and would have chalked it down to my large room size and the sub being insufficient for the room volume.