Peerless XLS12 box calculation with 2 PM and WINISD (1 Viewer)

[ClemensHelberg]

Hello,

Just saw, that a new release of WINISD PRO is available. Great program!

I have recently bought a subwoofer made out of 2x Peerless XLS12 and 2x 400g PMs fitted into one 32 Liter housing.

Unfortunately this enclosure seems to be way too small for this kind of subwoofer even with PM.

Now my problem:
I would like to remove one XLS 12 driver and fill the hole with an ARS500 subwoofer modul. I would like to simulate the box with WINISD PRO, but I have no glue how to input the TWO PMs into this program.

The data for fs and xmax of the single PM could be overtaken from single PM, but how to calculate the remaining parameter like Qms or VAS? Just double might be too simple!

Could anyone give me an advice how to calculate the enclosure in best way?

Bye
Clemens

 

[Jack Gilvey]

The data for fs and xmax of the single PM could be overtaken from single PM, but how to calculate the remaining parameter like Qms or VAS? Just double might be too simple!

Not really sure what you're asking. If you've got all the parameters for a single PR, then just choose put "2" under "Number of PRs:" on the PR tab.

 

[Janne Ahonen]

Yes, it is just the way as Jack just explained above. I must say that 0.50a7 is not officially released yet. So use it at your own risk. Multiplying the PR Vas with the number of passive radiators is what WinISD does internally. If you examine the electrical equivalent model of the box and driver, you'll notice that this is perfectly acceptable.

Note that passive radiator enclosures are not calculated to any specific alignment, so you have to experiment somewhat. 0.50a7 is better in this respect, because you can use mouse dragging for adjusting PR mass. Just enter some number for passive radiator extra mass, and then drag the enclosure picture to tune the design.

I still have to check and double check all the maths, because of the feedback I have received, I afraid that I have goofed up something (scaling on the multiple driver case). So stick with 0.50a6 if in doubt. Single driver case should work ok on both.

Regards,
Janne

 

[Jack Gilvey]

Here's a project you might be interested in, it appears to use the same parts you've got:
http://www.geocities.com/adrian_mack/index.html