Some Kind of Bandpass?

[Frank]

Hey guys! Anybody know what this type of cabinet called? Two drivers facing each other, with the output coming from the opening between them (or a port), a little like KEF's coupled cavity design.

[rone]

If the cavity does not have a port, you could call it a sealed slot loaded design - if the cavity is ported, it is a 4th order bandpass.

[Frank]

If the cavity does not have a port, you could call it a sealed slot loaded design - if the cavity is ported, it is a 4th order bandpass.

The slot loaded design sounds like what I'm about to try - for my car, using 2 8" subs. Is there any rule about how big the "slot" should be?

[MGrant1957]

Linear Power had something like that back in the early 80s called the 'Bass Vent'. A pair of 8" subs mounted face to face and driven into a slot vented chamber that measured 9x9x2 with a slot on the top that measured about 6x3/4. It was meant to mount through the back shelf/deck under the rear window and the bass would explode into the passenger compartment. They were sold along with the 2601 Bi-Amp, 2x30w + 60w to the Bass Vent. They didn't sound too bad but were kinda 'boomy' in the 40-60Hz range. It let you put a pair of 8" drivers in the rear deck without having to cut some big holes.

[cowtown]

Yours for only $1500, the Bang & Olufsen "Tulip" with 2x 6.5" drivers.

[abn1701]

Maybe I'm wrong but it seems that kind of loading was used in the legendary Muse 18 subwoofer .That was a high rated musical sub.
Cheers

[Frank]

Thanks guys!

[rone]

The slot loaded design sounds like what I'm about to try - for my car, using 2 8" subs. Is there any rule about how big the "slot" should be?

Really, most of what the slot will do is add a bit of mass. I haven't given slot loading much thought, so I am not sure if there is a way to "maximize" the design.

[billfitzmaurice]

Hey guys! Anybody know what this type of cabinet called? Two drivers facing each other, with the output coming from the opening between them (or a port), a little like KEF's coupled cavity design.

That's often called a manifold design. Probably the most popular examples were the EV MTL. They placed the drivers within the manifold, rather than the rear chambers, though acoustically it amounted to the same thing.

[Eurobob]

Compound loaded bandpass. 4th order. Trade box volume for efficiency.

[SpacePatrolman]

I'm no expert on bandpass subs, but I regularly read reviews where many such subs are said to be "one note wonders" and checking their charts does many times reveal a huge peak in their response. So while they use less power vs. conventional subs, they don't always sound that great. Though I suppose if the music one listens to concentrates its bass in the region the sub "specializes" in, this may be a moot point.