Hello Bob,
You should know that I've never personally heard many of the subs discussed thus far on your thread, including any from HSU, ML, Syzygy and SVS. I have, however, personally owned and listened to many brands and models of subs from JL, B&W, M&K, Vandersteen, Klipsch, Polk, Audio Kinesis and REL. For years I experimented with these subs in various quantities and room positions in an attempt to attain the highest quality bass in my system and room, initially with single subs, then dual subs and ultimately my search ended very successfully just over 5 years ago when I tried the Audio Kinesis Debra 4-sub DBA system in my room.
I was pleasantly amazed at the immediate and huge improvement in the impact and quality of the bass in my room produced by this 4-sub DBA concept system as well as how seamlessly it integrated with my Magnepan 2.7QR main speakers that only had a rated deep bass extension of 35 Hz. I've been using this system ever since with outstanding results on both stereo music and on my home theater 5.1 surround sound system.
I've read statements from various acoustic experts that 3-sub DBA systems are capable of bass performance nearly as good as 4-sub DBAs if each of the 3 subs are properly positioned and configured. I don't doubt this is true but I've never personally bothered to verify this in my room. But I've read numerous Audiogon posts from members stating that 3 sub DBAs have worked extremely well for them in their rooms.
My general advice, based on my experiences, is that 2 subs perform about twice as well as 1 sub and 4 subs perform about twice as well as 2 subs. Based on what I've read, I really just assume that 3 subs will perform very well but perhaps not quite as reliably as well as 4 subs.
However, I'm certain that a pair of subs, properly positioned and configured, are more than capable of providing very good bass performance at a single designated listening seat in virtually any room. The benefits of adding subs beyond 2 in the room will typically be perceived as the bass having increased power, impact, dynamics and a sense of ease quality along with it being faster, smoother, more detailed and this high quality bass will be perceived throughout the entire room, not just at the designated listening seat.
By now it's obvious that I tend to sacrifice brevity for the sake of detail on my posts, Sorry. Finally, you asked:
"
If I am considering Bluetooth subs, how about this one from Martin Logan. 12” drivers with Bluetooth capability, and they look similar to other models costing more (which doesn’t mean they sound as good . . Don’t know):
https://www.amazon.com/MartinLogan-Dynamo-12-inch-Wireless-Subwoofer/dp/B002O3W2SO/ref=pd_di_sccai_1... "
Since discovering and installing the A K 4-sub DBA system, I'm no longer reading about, researching and listening to the numerous subs available. I still haven't listen to the Martin Logan 1000W sub but I did research it a bit and read a few very positive reviews. This sub has a rated bass extension down to 22 Hz, has the necessary separate controls for volume, cutoff frequency and continuously variable phase, has the correct L+R rca inputs to connect to your preamp, has an updated wireless system, costs less than the Syzygy subs and looks cooler.
What's not like? I think a pair of these to start seem like an excellent choice for your room, system and circumstances.
Tim
