Dual SVS PB-1000 Pro versus Dual Rythmik LV12F- does Servo Technology Matter.

I am still mostly sold on the SVS but I wonder if the servo technology of the Rythmik might give me somewhat better performance for music.

I have to say I agree with @artemus_5 that debating between these two subs is small potatoes versus the negative affect the AVR is having on your 2-channel sound (although I do wholeheartedly agree with you idea of adding two subs as they’ll greatly improve both your HT and stereo experience). At this point I’d say get the SVSes as they’re probably cheaper and offer better integration tools, and use the $$$ saved to put toward the eventual purchase of a good stereo integrated amp you can seamlessly incorporate into your HT system with the front L/R pre outs on your Denon. You’ve got good speakers, and I think you’ll be amazed at how much more they’ll give you in 2-channel performance fed with a good stereo integrated. Hope this helps, and best of luck.

AVRs and serious music listening are entirely compatible, provided you know what you are doing.

Uh, due respect, no. Just...no. And it’s not a matter of setup either. AVRs are designed to meet a price point the mass market will accept, which of necessity means more critical and expensive parts (i.e. power supplies, etc.) are of significantly lesser quality than those that can be incorporated into a good standalone stereo preamp, amp, or integrated. Not to say AVRs can’t sound decent and be entertaining to listen to, but no one who’s serious about sound quality uses an AVR. Period, full stop. Heck, even people serious about surround music will use a better quality AVP and separate amp, not an AVR.

It’s a myth propagated by purists unable to accept the digital era is a massive step forward over the limits of tapes and valves. It’s sad they seem unable to let go of the past and keep finding excuses why analog is superior.

Digitally-sourced and -processed music can sound fantastic, it’s AVRs that are inferior.

Also, if I ever ask a question again on Audiogon I will ask that people that believe in cables, power conditioning, the superiority of analog, etc to avoid posting.

Well, if that’s the way you feel about it then don’t say something like...

While the subs will almost certainly work hardest for home theater I do want something that also works well for serious music listening.

When you say “serious music listening” on this site people will always point to your AVR because no one here “serious” about listening uses an AVR, and if you don’t understand that then it is you, sir, who have the credibility problem here.  Either just say “music listening” or post your suggestion on an HT site where you won’t have to suffer people who truly are “serious” about music listening and are more on your level. But don’t come on here and tell us our intentions are misplaced the way you asked your question. It’s not our responsibility to somehow know we need to dumb our answers down just for you.