Subwoofer Basics Help

Iso-Max makes a unit (Model SP-2SX) that will take the speaker level out from the amp or speakers and convert it to a line input. Thus, being able to use any powered sub.

ozzy

My vote is for REL also.  Buy a pair if you can.  You will get a more uniform bass response.  Hook you amp up to the high level inputs.  

2 subwoofers seems to be popular. At what price point does a single subwoofer out perform using 2 subwoofers? Are there issues with subwoofers feeding AC noise into systems or grounding issues that impact the rest of the equipment? 

2 subwoofers seems to be popular. At what price point does a single subwoofer out perform using 2 subwoofers?

Two subs is popular for a very good reason.  Tough to answer your question in general because there are many differences within each brand’s lineup, but just to use one example I’d take two SVS SB1000 Pros at $950 over one SB3000 at $1100 especially if it’s primarily for music.  The SB1000 doesn’t go as deep as the 3000, but it still gets down to a legit 20Hz (-3dB) and you get the benefits of the subs not working as hard, providing a more even bass response, and dealing better with room modes/issues.  Just one example FWIW.

Yes the record out is full volume. As others mentioned your best bet is sub with high level connections like the REL. 
 

You could use the volume control route out of the record out but you would be doing a lot of fiddling with it every time you changed the volume.