Single vs Dual Subs

I know I'm late to the party, but must chime in.
Bass below 80hz or so is not localizable. Unless your room is HUGE.
The advantage of double subs is reduction in standing wave peak/null situations.
Subs located asymetrically will tend to cancel out each others standing waves producing a more uniform in-room response and a larger sweet spot....which is important for HT duties where a crowd may show up.

Budget is around $2k (...) you could get a pair of new subs from Hsu Research...

That is the answer to your query, IMO.
Not perfect but good performance. Start with placement on the same plane as spkrs & take it fm there.

To Bob's point on EQ to 300 hz.
This is obviously room dependent. Every listening room I've had (and measured) has had obvious issues below 150hz. IME, above this point (including the falling treble response I usually get above 10khz), room effects are still present, but much less severe/troublesome. Between 80ish hz and 150ish hz, room treatments (hemholtz resonators or "Bassbusters") have proven very effective in my efforts to "clean up". Below 80ish hz, it's either soffit or EQ, unless your room is large enough to approximate an anechoic chamber.

My bottom line: I can usually live with the "bottom end" room effects between 150hz and 300hz, "resonate" them away between 80ish and 150ish, and EQ them below that. This is just my preferred solution. FWIW.

Marty

A-gon'r Kr4 has compared many of the available room correction devices (not sure about the SVS) in his work for Stereophile. You might want to drop him an e-mail.

I did. Unfortunately, he's in the process of reviewing the SVS/Audyssey right now, so he couldn't comment.

I think it's boiling down to this. Two identical subs from either SVS or Hsu, and see how well I can work things manually. The PEQ can be added later in several different ways. Leaving some budget for such future devices, I'm probably looking at a choice between 2 SVS PC12-NSD ($569 each) and 2 Hsu VTF-2 ($549 or $649 each depending on finish). I lean to the cylinder concept for subs, but I know my wife would prefer boxes. Hmmmm...

Thanks again,
Lou