Subwoofer Choice

I own Sopra No2s

Congrats on the purchase of the No3s.  I have a fully treated room w/ bass traps and a JL F112v2.  I find that the Sopra's alone do a great job with a good recording.  If the recording is thin I'll activate the sub to correct the recording.  I don't pay attention to stats, they mean nothing to me.  From real experience, properly positioned and adequately driven, the Sopra's will make a ton of bass.  They are front ported and have a good deal of speed IME.  Be sure to match the speed with the sub.  Speed isn't about size, it's about quality of the driver and power/electronics.  I have two (2) SVS SB4000s in my HT room and IMO the JL is considerably faster.  I the JL makes more power and has a large toroidal transformer that the lower priced SVS does not.

Probably more than other speakers, the Sopra's are sensitive to the grip of the amp.  Pairing your No3s with an amp with a very high damping factor will give you crap ton of clean, fast bass.  

I would get the new speakers in place, run them in, and then decide what your needs really are.  Set up properly with a good source the No3s will be darn near full range.  Again, I always disregard specs and trust my ears.  Good luck and cheers.

Thank you for so much good information, this forum never disappoints and is always so knowledgeable!

So, after further thought (and contrary to my follow up post above) I decided to stick with the REL and buy up to the S line.  I picked up two S/812s.  Maybe the JL hits harder and lower, but hopefully I'll be just as happy with the 812s.  

Someone mentioned the JLA CR-1 which I was considering.  However, can i use it with my integrated amp (Michi X5)?  I don't think i can pre-out and then back in to the same amp can I?

Thank you

@james633 @ozzy 

HSU ULS-15 MK2

@bound4h , The JLA crossover is a good analog crossover however the best sub management systems/crossovers are digital. Check Out MiniDSP which makes several reasonably priced units. They also have room control features, Dirac Live I think. There are now several digital preamps that have sub management, room control and EQ built in, MiniDSP, Anthem, DEQX and Trinnov to name a few. 

All subwoofers that have only one driver are compromised by Newton's third law. Sub drivers are heavy and play low frequencies at higher volumes will cause the entire enclose to vibrate/shake. This creates distortion and compromises dynamics. It does not matter how heavy the enclosure is. You just raise the frequency the enclosure shakes at. Some manufacturers have taken this into account in newer designs that use two opposing drivers that balance each other eliminating this shaking problem. KEF, Magico and Martin Logan all make "balanced force" subwoofers.