6th Order Bandpass Subwoofer (rear & front chamber size?)

[phase_accurate]

* For this reason I don't undertand why the 6th order bandpass doesn't have the same box in her 2 chamber

With a sixth-order bandpass you have one 2nd order bandpass (i.e. tuned box) in front of your woofer and one on the back.

The woofer outputs the same signal on its front and on its back. If these are summed as is then you will have no sound - they will simply cancel out. The same happens if you use any form of waveguides or resonators or whatever in front and on the back of the driver. If these are equal then the output is again nulled out due to the fact that you feed both of these contraptions with the same signal but 180 degrees out of phase.
It is getting interesting as soon as those resonators are tuned differently. Not only do you load the driver over a large bandwitdh (whatever large means) - the difference of the inherent natural phase-shift of these resonators adds another 180 degrees, helping to add the SPLs of the front and back efficiently.

Regards

Charles

[RobWells]

Try downloading winISD for modelling.

Rob.

[Thawach]

Hi nick

Two ports are difficult to tune it. I think you would like it when
it works for your HT. I had ever built it(8"). The spl is highest.
To be careful!! The cone has a good sound (POP).I know that
time. Oh wow it is funny.


regards