Which REL sub, R528 or B2

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...

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

Case reopened. My main speakers (Silverline Preludes) get thin around 50 and thinner around 40 (ignore the specs for these...they're kind of silly), so the REL sits at 50 ish with frequent level adjustments (a "chicken head" knob allows easy gain changes) relative to source material. It does "charge the room" though, so everything sounds better all the time. Building your own cable is easy and the angled Neutrik Speakons are great and sit better. Another note for naysayers...in the March issue of Hi-Fi + a reviewer (Alan Sircom) says about the REL R-528SE, "Rel subs are always fast - it's one of the reason they consistently score well in hi-fi magazines, they are some of the only bass bringers that can keep up with snappy little sealed box speakers with ultralight 100mm mid-woofers." He's just another dude...but still...

I currently use a REL T5. It can keep up with my Sonus Faber Guarneri
Hommage's! IMHO, any sub that can keep up with these speakers is anything
BUT slow!!
The set-up of a sub- and REL is no exception, is crucial in this regard, wrong
set-up and the results will be a mis-match with the sat's....leading to the
impression of a "slow" sub. Subs are NOT 'plug and play', particularly
when you are trying to get the blend with a quick mini to be seamless. IMHO.

YEAH! So now the "Fast REL" contingent is leading in the total point score...this could be a win.