REL Subwoofer: Speakon or RCA?

@daveyf  
  
Not an opinion, based on pure performance, an equally priced sub from say Rythmik, SVS, PSA, JTR, etc. will easily outperform it. REL doesn’t offer deeper extension, louder output, better microdynamics, more musicality, etc. In today’s age, you can get better for your money, they may sound good, but not as good as it’s modern competitors.

REL SUB-BASS SYSTEMS are not designed for use in applications where the main speakers are externally crossed-over to eliminate lower frequencies from the mains, to substitute for poor bass performance of main speakers, nor to induce terrified responses to explosions while viewing the latest mindless action movie. In those applications, mzkmxcv is correct that REGULAR SUBWOOFERS provide better results than REL.

REL SUB-BASS SYSTEMS are designed to provide room pressurization of frequencies around and below 20hz and to slightly augment bass performance of full-range loudspeakers in that region. The net effect of a properly implemented REL is audibly improved soundstage and a solid bass foundation for music with near perfect integration with most full-range loudspeakers when used with the hi-level connections from the amplifier’s speaker outputs. If that is the intended application, nothing else compares to the RELs IME.

Dave

Over the years I've heard systems with various subs from old Velodynes to Vandersteens and others not having a V in their names, and RELs certainly hold their own compared to anything out there, including my 92 lb monster studio sub that's actually flat to 19hz...RELs are great designs, period. My 2 RELs cost 200 bucks each used and in mint condition by the way (Q150e I bought first maybe 5 or 6 years ago, and Q108 MK II I found maybe 2 years ago), perform perfectly and are musically transparent in the sense that when properly set up they simply disappear. 

@dlcockrum  
  
Nice breakdown.  
  
One thing I would like to touch on: 
  

REL SUB-BASS SYSTEMS are designed to provide room pressurization of frequencies around and below 20hz and to slightly augment bass performance of full-range loudspeakers in that region.

You would have to go really high up in their price range to get that low. The $1300 T9i is only be down to 28Hz at -6dB. And while we would are disregarding the benefit of the REL’s integration, the ~$500 Rythmik L12 (which is very musical for the price) is rated down to 12Hz at -6dB, for all those pipe organ lovers, something even the $7500 REL reference model doesn’t quite achieve.  
  
But it is true most music doesn’t go below ~30Hz, though it’s still nice to have a subwoofer that can still handle that without strain, as those specs are given at low wattage, and they very much so would have some compression on their low end when playing back at reference levels.