What is the best way to hook up a sub to the 2150 while keeping the main speakers full range? I'd like to augment my mains which go down to about 40hz and have a sub fill in the rest down below.

I'd also like to achieve a more seamless integration between sub and mains. This setup is mainly for music. Short of plunking down serious cash for an REL and using their unique hookup connections, should I:

1. Set the sub output of the 2150 to bypass and hookup a single interconnect to the line ins of a sub (split to L/R signals at sub end if needed)?

2. Use the pre-outs of the 2150 with 2 y-splitters and and run a set of interconnects to the line in's of a sub so the sub "sees" exactly the same signal as the mains. I will then not use the sub out of the 2150.

3. Something else I haven't come across or thought of.

I like option #1 for ease and less cables, but is the "purity" of the signal the same as using the pre-outs when the sub out is set to BP?

Full range speakers plus a sub can only be achieved if you don't use the 2150's bass management. You would have to set the bass management switch to bypass, at which point the sub output is unused. There are two ways to wire it to achieve full-range mains, although only one is guaranteed to do what you want.

The first option is to pull the jumper bars off, use y-splitters, and feed the pre-amp outputs to both the main inputs and the subwoofer. This feeds full-range to both the sub and the 2150's amps. Your sub's low-pass filter will control how much of the full-range signal the sub reproduces.

The other option is to run the speaker wires from the 2150 to the sub and then to the speakers. This one only works if the sub's low-pass filter is alone (no corresponding high-pass filter). If there's a corresponding high-pass filter, you end up with the same situation you'd have when using the 2150's bass management.

If your mains go down to 40Hz, I'd also at least try the 60Hz setting on the 2150's bass management. I say this because they probably start to roll off some around 60Hz and a little sub calibration (which has to happen anyway) could yield a very nicely blended match-up. It may not be exactly what you are looking for, but if you haven't tried it yet I'd suggest giving it a listen before ruling it out.

thanks for the info Gonk!

Gonk - I run my sub with bass management to bypass and get a signal to my sub no problem. I use the sub's crossover to match my speakers.

Am I misunderstanding you when you say the sub output is unused?

I was thinking that the sub output was inactive when "BYPASS" was selected, but I found the following on page 15 of the manual:

Based on that, you would get full range to the speakers and full range to the sub when in BYPASS mode - something that I did not realize...

That's cool. I don't think it's a sin not to have the manual memorized!