Originally Posted by mojomike
I was one of those people who couldn't wait and I gave up on that one a long, long time ago. I'm glad I did because there are too many great subs out there now to be waiting around for who knows how long. I'd be shocked to see that sub out by year's end and they've been talking about it for well over two years already.
I meant to say that "some people CAN wait to get their hands on the BMF".
I was not suggesting that the OP wait for a BMF. I was suggesting that the performance differences between a well designed passive radiator sub, a well designed ported sub, and a well designed sealed sub are not very significant.
For the sake of discussion if subs with passive radiators make a "thut" noise as our friend the REL dealer has suggested, than we can also say that ported subs produce "chuffing" noise when pushed at resonance.
Neither design is likely to make any rude noises when operated within design constraints.
More than a few people are into sealed designs. Sealed designs will produce more and more distortion when pushed, unless there is some form of limiter.
In sum, I was just trying to suggest to the OP that a well executed passive radiator design could be a prodigious performer, and that talking about "thut" noises out of context did the OP a bit of a disservice.
Perhaps Mark Seaton will drop in and update us on the progress of the BMF. Also, Mark Seaton among others has and can produce excellent subs that are sealed, ported, or have passive radiators.
I will leave you with this quote from Keith Yates an HT designer who spent 6 months testing some of the worlds best subs including the Genelec HTS6, and the Velodyne DD-18.
"If you have trouble believing that subs of different sizes, driver configurations, amplfier capabilities, cabinet makeup, countries of origin, and prices could possibly sound alike on challenging material, just take them outside, away from walls and the standing waves they create, match the levels, and listen for yourself."