Here is the thread where I learned about Rythmik and about direct servo, if you are interested in reading it... http://www.whatsbestforum.com/showt...al-fast-and-accurate-subwoofer-you-have-heard
I believe that yours and mine quest for the perfect subwoofer might be similar. I too was looking for a sealed subwoofer, preferably with built-in filters. When I heard the Velodyne DD+ series, I was instantly sold on the tightness, dry punch and musicality.
Having heard and now using a DD+10 myself, it has really raised my expectations of how a trimmed subwoofer system should sound and performed.
I've visited a couple of pretty well-built home cinemas, and one very well-built cinema, and listening to the low-end performance in each cinema, all I could think of was "why didn't they go for the Velodyne subwoofer sound?". But that's my taste and it can of course differ from somebody else's taste.
Personally, the DD+10 was the best candidate for my room, because I wanted the fastest of them and figured that the smallest model would give me that. It still pack a lot of power, and I'm not close to using it all - except when listening to a DSD recording of a church organ playing one of its longest pipes.
I'm also using the JL CR-1 outboard crossover system as well. Honestly, the only other subs I've had in my system were Wilson, Focal and Velodyne.
Ah well, the Bryston will hopefully show up next week.