Rel Strata III versus Rel Britannia B3

The DD series subs from velodyne leaves the REL subs in the dust. The onboard EQ shows you what the sub is doing in the room. I have mine set at 6 out of 100.

Addressing the B series vs. ST series question of your post, when I bought my B1 the dealer told me that REL says the B3 actually falls performance-wise between the Storm and the Stadium. Hard to believe, but that's what he said.
Second, since I have owned both Velodynes and RELs (and now have the REL), Flemke is not wrong. The EQ function is a tremendous advantage. However posts like Nolitan's above get to the heart of the matter, which I believe is attributed to the idea that (based on my own observations -caveat - not backed on science but listening) the Velodyne 'shoots" the bass at you (and it is nice in its own way) the REL loads the room and the bass seems more natural and musical. That said, I could live with either. If you have an SPL meter and are willing to work with the set up of the REL you can mitigate the Velo's EQ advantage a lot.

Hi all, figured I would provide a few remarks as an after action report. I ended up with the B3 and have been listening to it in my primary system over the last 5-6 months. While I have not been able to directly compare it to other subs in this system, there are a few definite things that I have noticed. First, as others have mentioned (and when properly set-up) the B3 simply "disappears" in the room. Aside from the borderline small appliance size, you would never know it was on unless you actually turned it off. However, when it is off, you immediately notice the difference. Lack of depth, dynamics, and sound stage. Don't get me wrong, the S5e's can sing on their own, and are well known for their disproportionate "bigness". The B3 simply takes this to another level. After 6 months, I still simply sit here and listen to the music and marvel. For someone as OCD as me, this is a small miracle. Setting it up took sometime, but if you follow the excellent REL guidelines and are not afraid to experiment with various locations in your listening room, you will not be disappointed.

Thanks to everyone for your thoughts - definitely appreciated!

Froody,
That's real HOOPY!
I have had the same experience with the REL q150e,  t3 & t2 I own.
Maybe one day I'll get a B3 ;-)

Ive owned both and currently run a T7 Rel...IMO the Strata3 is easier to setup and run.The B3 seemed to me to be slower in responce.I ran both with Dynaudio,Focal.Having said that the new series is much better,much better IMO