Two Subs?

Bob - What do you mean when you say "standard REL speaker level connections"?

I suppose he means the REL recommended approach of getting the signal to the sub from the speaker terminals, then the main speaker amp and the speakers themselves are still reproducing the whole bandwidth.

An alternative approach places a crossover between the pre and amp to filter the frequencies the sub is going to reproduce so that the main speakers only reproduce above the sub. Most speakers increase distortion at lower frequencies, so that's one benefit pursued by this approach. Same for the amp: you save headroom for the "higher" frequencies.

Of course the approach also has a downside: an additional circuit in the signal chain (the crossover itself), plus interconnects, etc. Another downside is the main speaker woofers are yet another source for low frequencies, helping to smooth the room response in line with what additional subs do. So a tradeoff, like we usually find not only in audio. Pick your poison, I guess! :-)

Got it! Thanks for the explanation. Hookup of current REL is via the speaker terminals. Dealer did the hookup upon delivery of my monoblocks. He says I'm precluded from wiring to my amps because they have a floating ground. So, a second REL will be wired to second speaker. Apparently, not optimum.

You may find this article interesting.
http://www.harman.com/EN-US/OurCompany/Innovation/Documents/White%20Papers/multsubs.pdf