[Polarbear]

I know the dipole woofer are quite directive in the bass area. Is it the same rule for U-baffle? Would it beneficial to point the U-baffle at the listener?

Cheers
Bjørn

[opnly bafld]

http://www.musicanddesign.com/u_frame.html


Lin

[Polarbear]

Thanks Lin

I have read these pages, but I 'm still confused.



From what I can see out of these charts (at left), the respons of the H-baffle is least on axis. And the U-baffle is at it's peak at +45 deg. Am I missing something?

cheers
Bjørn

[Rudolf]

Bjørn,
top of the diagram is on axis front, bottom of the diagram is on axis rear.
So +/- 45° from axis would be almost the same SPL for a U-frame. Not much directivity in that range. It is the difference between front and rear radiation you want in an U-frame.

[Polarbear]

Bjørn,
top of the diagram is on axis front, bottom of the diagram is on axis rear.
So +/- 45° from axis would be almost the same SPL for a U-frame. Not much directivity in that range. It is the difference between front and rear radiation you want in an U-frame.

Ahaa. Thanks Rudolf. That makes more sense.
So it's not much use to point the U-baffle at the listener for SPL purpose. Could be useful to control room-modes though?

bj

[Rudolf]

bj,
in the first place a U-frame will be useful to have better control over the rear bass output. If you can´t place your OB or H-frame far enough from the front wall, a U-frame should be helpful. As shown in the diagram, regarding radiation to the front a U-frame of certain depth is 6 dB more efficient than a H-frame of the same size.
Because the U-frame has less directivity than a dipole, in theory the U frame should excite more room modes than a dipole. But if a U-frame gives you more freedom of placement in the room, this could easily be more helpful to control room modes than the radiation pattern.