Sub Question. One higher quality sub or two lesser quality? (Rythmik vs HSU)

mapman

The Audio Research SP16 has two stereo main outputs. One goes to main amps which remains in stereo and the other to the sub.

I understand that. On many ARC preamps, the main outputs are internally wired in parallel. That would mean you'd get mono out of both outputs even if you only wired one for mono. It looks like the SP16 is an exception.

@cleeds

sp 16 may or may not be exception. As I indicated I am not merging output with a Y connector with the ARC as I mistakenly indicated initially so in fact I have not encountered that scenario.

I suppose one would know for sure pretty quickly if one tried that.

I looked a Rythmik before purchase two REL S2 SHO subwoofers.  I thought REL's high level connection made sense.  My goal was to have the best of two worlds, home theater and music.  I like REL's technology because it makes more sense to blend subwoofer's with the main speaker so they act like additional woofers to extend the bass seamlessly.  I also think two are better than one to help balance things out.

TWO..or more,HSU and SVS both good as I am sure the others mentioned are too.
SVS lets you have free shipping both ways..in case you wanted to send it back,
SVS Also has 1 year trade up policy.Example,
You buy 2 PC2000[Pro version Now but they have the PC2000's at this time]..
and if later in the year you want to go bigger then send them back
and
you get FULL credit towards the Subwoofers that are higher up the price line.'
Free Shipping all the way around.
Power Sound Audio seems to make nice Subwoofers also,
I have a friend that has one and enjoys it.
He[Tom] used to be Part of SVS some years back.

I'm a little disappointed to hear that with two 15" woofers you are even looking for subs. I am considering the CW's. I understand they don't get down to the lowest octave. Not going to derail the subject but could I ask how big your room is? Might have missed it.