How to magnet mount a subwoofer

[thadman]

I've got four Aurasound NS15s I would like to use for a distributed sealed subwoofer setup (ie Geddes alignment). I'm interested in coupling the frame of the driver to the front baffle with screws (gasket in between) and rigidly coupling the magnet to an extensive network of internal bracing. I will "float" this box inside a larger box with a viscoelastic damping layer (probably Green Glue) in between the boxes.

Rigidly coupling the magnet of a traditional subwoofer appears pretty straightforward as most magnets are of the cylindrical topology. However, the Aurasound possesses a unique NRT motor, which is not cylindrical.

Here is a rear photo of one of my NS15s



and here is the PDF file

https://www.madisound.com/store/manu...4a51f856ee0d7d

Any thoughts?

Thanks,
Thadman

[Don Hills]

You would only need to mount a driver by its magnet if you were using it at higher frequencies, where the magnet mass could resonate with the compliance of the basket. It's the classic "weight suspended via a spring" scenario. (magnet=weight, basket=spring).

Subwoofer frequencies are far below the resonant frequency, so mounting via the frame (rim) should be fine. Mount the driver to a ring attached to the internal bracing. Use foam to seal the (small) gap between the driver and the front baffle.

[buggsson]

Very nice drivers. They were on my shortlist for a while, until I found out the cost, and my wife's view on the subject..........

By mounting by the rim you are then much more likely to set the walls vibrating than if you isolate the driver from the box as much as possible. This has nothing to do with frequency, it's just physics, it's just the membrane pumping against the trapped air affecting the driver. That is why some use for example rubber grommets when attaching the driver to the box by the rim. This is also valid for subs, and there are papers written on the subject. I would opt for rubber grommets and a steady grip on the magnet, that is what I plan to do myself. You can also do as Linkwitz (spelling?) has done on the Orion, where he has fastened the magnet and then just barely? tuches the inside rim of the baffle with the front of the driver.

As for fastening the magnet, the angle should be quite straight forward to find out. Then maybe a router could do the trick if there is a tool with similar angle available to do the hole? Otherwise, I think a poperly applied jigsaw (one of those hand held things is what I'm after) could do the trick if the angle is within range, even if you have to do it free-hand. A circular jig might also be possible to do quite simply?????