Which REL sub, R528 or B2

Xti16, one more question, have you tried the SignalCable subwoofer cable?

Bo1972 you have confused me with the "slow" comment a bit. A reviewer of Tone Audio writes "B2 was more then fast enough to keep up with these speakers (panels)" and again "it was also a great match for the Manger Zerobox speakers and that is one of the fastest speakers I've ever heard"
It must be some setup issue...

My experience is limited to Velodyne SPL-1200R. I was not able to fully integrate it with the mains. I could feel some strange body in the system. Bass was to tough, not musical and tiring after long listening. I used hi level connection then. Maybe if I had used a better quality speaker cable ....
and reliability problem. I used to leave the sub in st-by mode. One day, after thunderstorm ... My electronic friend looked inside, no fuses, no protection, assembly quality like those from China. The authorised dealer said you have to replace whole electronics, can't replace parts. This is how it's designed. So I said to myself no more Velodyne.
The advantage of REL is it's connectivity, I'd like to use it in both, HT and stereo system.. I took a look what the guys from positive f use, mostly rel's if any. Unfortunatelly they are not available in my area for a test. I found some posts here, on audiogon saying a few persons used C1 and REL's with success hence the decision.
Thanks for your input, I'll have to rethink it....

Bo1972, it makes sense what you write but I'm looking for a sub that is musical first of all, I want to implement it in audio system and there are not many subson the market making "music" . Majority are just headbangers, exellent subwoofers for HT but not for music. Example, my Velodyne that I had. It's harness was to much for a long run. But it was great in HT, great.
Big advantage is REL connectivity also that makes them more versatile, useful. Again, when I got my Velodyne I thought why the heck I can't connect HT amplifier and stereo amp at the same tame. Maybe Rel is not the fastest in the world but all the virtues plus very good bass they produce make them one of the best options for my purposes.
Thanks for your comments anyway.

Xti16, what crossover frequency have you set up with C1? How big is your room?

My C1 is the original one, stands are filled with sand, actually "cats" sand, both posts filled. I've read good things about MKII. Better clarity and better at low level listening as you said.
33 hz makes perfect sense, I've seen frequency response to crossover plot of B2, quite interesting. The output doesn't prgressively extend towards higher frequencies when you change crossover setting but it acts more like tilt control.
You have kind of "Audio Physic" setup. They recommend speakers on the long wall. Your sub is not in the corner then, how far is it from the wall? the front wall I mean, not the side wall?
I've ordered a REL, and have some expectations...

Bo1972, you are kidding, right? you must be kidding, just having a good time on Audiogon. Somehow I recalled Forest Gump...

Bo1972, what is best for you may not be the best for everybody else. You write in your review taht you crossed over your sub at 120 Hz and you are using full range speakers? Do you use one sub only, corner placement, crossover 120 Hz? That's really interesting.

I have my REL sub. Seamless integration with the system, perfect. Bo1972, you made a great suggestion to use a calibration system (in my case Yamaha Ypao, yours audyssey)for setup... I have balanced speaker volume and the sub... sub's volume is only 5 clicks up.. I set it a little bit to high by hearing. Crossover 34Hz is fine.
Soundstage has improved, more palable or more "touchable" as Bo1972 says, kind of energized and obviously better bass, deep with great control. It was a good investment, great upgrade.

Wolf garcia, apparently you don't have idea what you are talking about. you are the man. that's for sure.

You should have stuck to the male stripper career, your EGO fits....

Daveyf, 100% correct.

I've ended up with B2. Looks better then the black cube, 528. A matter of taste. I haven't had a chance to compare them sonically. Perfectly integrates with the system.