Converting a woofer into a passive radiator

[bentoronto]

Now I'm back to square one.

The problem is that this thread seems to me to be filled with people who think they know the theory of PR boxes but don't (myself included).

My guess is that we are talking about the usual box tuned to be anti-resonant to the driver's resonance in that box. The PR device does not alone determine the box behaviour, it is just one more factor that Helmholtz probably figured out 150 years ago that determines the box behaviour.

For any PR I've ever digitated, the device's resonance is well above the speaker working range. That makes it "mass controlled" by the box.

I sure wish somebody who understood the theory would post.

Ben

 

[tb46]

Hi bentoronto,

Post #41: "...For any PR I've ever digitated, the device's resonance is well above the speaker working range."

Maybe Jeff Bagby, or Dr. Geddes will chime in on this, and it's been a while that I have build a PR subwoofer system, but every passive radiator that I have used-or seen-ends up with a resonance frequency well below the system resonance, if for no other reason, than for the substantial added mass necessary to tune the system. The deep notch below system resonance in the response of a PR subwoofer is aligned w/ the PR's free-air resonance.

There is a nice FAQ section on AESpeakers website:

AE Speakers --- Superb Quality, Unforgettable Performance, Definitely.

Regards,