Subwoofer Choice

First I'll admit I only have ownership experience (lots of listening time) with REL.  I'm sure other manufacturers also make fine low frequency speakers.  

I have the Sopra 2

I had an old REL, a later model Strata I believe.  For its time it had a marvelous tonality and seemed like good control.  Then last year I bought an S/510 and discovered that the technology has moved forward.  

You'll find the S/510 is a tight, fast acting low frequency speaker.  It delivers the texture of the instrument, the skin of a kettle drum, brass of a pipe organ, metallicity of a an electric bass and woodiness or a stand up bass with a palpable realism that brings the lowest register we hear to life.  I would have purchased the 812, the Carbon Fiber or maybe even the 212, but I'm space constrained and so I went with the 510.  I can assure you I do not regret the choice for a moment.

If you have the room, go bigger.  if budget is the constraint then two 510's would be preferable to one larger unit.  However, if you can afford the Sopra 3, and whatever else is in the kit, then I suspect you can reach a pair of the larger subs.  What about a pair of the 212's?  I'm seriously lusting after that config.

Also, don't be so concerned about roll off.  You can adjust the the gain and crossover and can quite easily end up with too much low drive at the very lowest end, as I suspect can happen with all quality subs.  I have mine dialed in to very nicely support that lowest end of the Sopras while delivering texture and the right amount of presence.

As an aside, when I replaced my older REL I immediately discovered new texture to almost all of my music.  I listened like that for most of a year, the older REL sitting in a corner, waiting to be sold.  Then one day it dawned on me that I was being stupid and should hook it up!  So now I have the older Strata crossover set to it lowest setting.  It really only comes to life at the bottom end but gives an extra drive down there.  It especially helps with the bass presence in live recordings of bands like Phish, Grateful Dead/Dead and Company, String Cheese, .Moe, Goose etc.  It's not the perfect set up, but it makes us pretty happy!

I find the REL works quite well with FOCAL.  Look at your space and budget.  Any of the models will work.

I submit the room and what speakers you have are just important as the subwoofer manufacturer. That being said, I prefer REL Reference subwoofers. I've found that sealed subwoofers work better in my room. REL reference subwoofers are the only subwoofers that completely disappear in my room/ system. 

In my view, Rhythmiks are just as good, cost less, and have variable phase which is critical for integrating subs with room, speakers, and one another.

Well, I am using 4 JL-F-113 subs in my room. I like the JL's built in room analyzer that adjust to the peaks in the bass within the room. Each of my subs is set individually. I also an using a JL-CR-1 electronic crossover for that final setting.

I have never tried Rel’s they get some good respect in the Audio Forums, so they are probably a good sub. But... I still like the controls the JL subs have.

BTW, I am using Focal Sopra 2’s.

ozzy

Why not Svs , sealed boxes are more accurate then ported or vented which Rel 

isit has a passive radiator on the bottom , I have heard  most of their models up to $3k

the most accurate which my brother has. Is the JL audio. Fathom 12 

whichhas full room correction built in. $5k retail which btw is Sealed 

the SVS ihad the SB -sealed box 3000 which was very respectable and great app for adjustment at $1k. I moved to to the SB - 4000. Which is a Big step up in output 

and tunefull accurate bass Rel cannot match especially in the $1700 range 

and  tons of bass slam not that big but very dense 102 lbs ,the driver alone os around 50 lbs , SVS gives free delivery , and a 45 day audition , plus a 5 year transferrable warranty the others Donot.  You have nothing to loose and a very good app to adjust from your chair , not the back of the sub .