I've heard the REL B3 and it's not a musical sub IMHO. Just OK for movies but I'd never use one in a 2 channel system.
never heard the JL Audio.
never heard the JL Audio.
i have heard many great things about JL. I have heard REL and liked them...as with all the things the match is the key (in this case with your system, your speakers). Flexibility of crossover is important, and so is perceived speed of sub vs your speakers. I also like the DD-series subs, and have heard the current DD Plus series is far better. good luck and pls keep us posted.
I just went from a Rega Vulcan to a REL R-528.. I'm still trying to figure out if it's actually 'musical' the WOW factor is blowing me away.. this particular REL has much more reserve, plays with a sense of total control and lack of constraint or strain... and of course goes down ALL THE WAY but is it more musical? I think I would rather see a sealed air suspension enclosure instead of the downward passive radiator but who knows... I have not owned any other subs than these two. All the other subs I can recall hearing at dealers over the years do not come close to these two however.
Forgot to mention. Getting the timing/phasing right is the tricky part. I would assume the JL would be the same. On the Rel there is a phase switch 0 or 180 degrees. Then you have to physically move the sub closer or farther to get it right on. Once you get that right the crossover point and gain is pretty easy. You should not be able to hear where the sub bass is coming from.
for the Money the Emotiva 12 is very close ,and actually has better output from 40-60hz, under 30 the JL audio takes over
and the Emotiva is very decent at 1/4 the price that is saying alot , I would like to mention .I bought a solid aftermarket power cord from Signal cable a thick 10awg
and remember the cheap steel fuse must go , go to the Cable Co. and buy a Hifituning Silver fuse . Silver has 8x less resistance then a steel fuse .which means faster more articulate bass 100% guaranteed,the laws of physics don't lie with a sub current is very important !!
Kiza, I also have the M3 and two JL F110's with Usher BE-718 monitors. It works really well with the bass management feature built in to the amp and now I don't worry about the woofers in the monitors getting damaged when I play loud electronic music or other stuff with trumped up bass. It was a "set it and forget it" procedure when I put it together. I let the JL automatic adjustment system run its course with the supplied microphone and run them with their volume at the neutral or middle volume position and no other adjustments. I set the high pass filter on the M3 at either 60 or 80 Hz and after that no fussing necessary. Too easy.
Saw your post on F110 thread wanted you to know I tried the F112 I thought they would be perfect but they couldnt keep up with my electrostatic speakers settle on the F110 although I would like a little more bass they integrate perfectly with detailed bass as you mentioned. Recently purchased Crystal Clear Audio Master Series and they brought it up another level. Good Luck you have a great system and to me it looks like you already hit the lotto.