Rythmik / GR servo sub - shallow enclosure?

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wwh

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Rythmik / GR servo sub - shallow enclosure?
« on: 5 Nov 2012, 05:38 am »
I'm pondering adding a Rythmik / GR sealed servo sub (A370PEQ + SW-12-04) to my system, but due to space constraints I need something that can sit close to the wall and not intrude into the room too much.

I came up with the 1.8 cu. ft. design shown below, which is 38" wide, 16" tall and 9" deep (all 1" MDF), and has both the driver and the amp on the room-facing side.

If I understand correctly, the driver is 6 3/8" deep, so this leaves a little over 1/2" between the back of the motor and the enclosure. Also, this leaves relatively little space for damping directly behind the cone. Could this be a problem?



Thanks.

Bill

Danny Richie

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Re: Rythmik / GR servo sub - shallow enclosure?
« Reply #1 on: 5 Nov 2012, 01:52 pm »
The shape is fine and since this is a sealed box and only covering the lowest octaves then the shape will have no adverse effect.

However, those are some large panel areas with very little bracing. In our boxes I typically have a brace at least ever 3". It takes that much bracing to minimize any panel resonances. Those woofers will put a lot of pressure on that box.

jparkhur

Re: Rythmik / GR servo sub - shallow enclosure?
« Reply #2 on: 5 Nov 2012, 02:53 pm »
Add a third brace (like Danny said)  in the middle and maybe one on the other side of the speaker/amp.   also... cut holes in them for air flow.. round over all edges..

Looks nice.. 

JP

steve f

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Re: Rythmik / GR servo sub - shallow enclosure?
« Reply #3 on: 5 Nov 2012, 11:40 pm »
You don't have to round off any pieces. It's a sealed box. Bracing is important though. In narrow boxes, I glue a small ball cut in half that fits between the back of the woofer and the back wall of the box..just don't cover any back vent through the magnet structure. Squash & racquet balls work well. Mount the drivers with Tee nuts or furniture inserts.

jparkhur

Re: Rythmik / GR servo sub - shallow enclosure?
« Reply #4 on: 6 Nov 2012, 12:08 am »
Even sealed subs should if at all possible have rounded over internal edges

wwh

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Re: Rythmik / GR servo sub - shallow enclosure?
« Reply #5 on: 6 Nov 2012, 05:05 am »
Thanks guys.

Here's an updated diagram with more braces. I still need to calculate the resulting volume, but I can always extend the enclosure lengthwise to compensate. I should also probably add bracing for the ends.

I've guessed at the general shape of "Brace C". Is an engineering drawing of the SW-12-04 driver available?

Also, I was thinking earlier today (dangerous I know) if a two driver setup would be better for my situation. I know the SW-12-08 is no longer available, but is there an ETA for a Rythmik amp that can drive two SW-12-04s? This is for a music-only system (no HT), and I generally don't listen at high levels, but my mains are very efficient (Klipschorns) and the sub would be for sub-20Hz to around 35 Hz.



Bill

Danny Richie

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Re: Rythmik / GR servo sub - shallow enclosure?
« Reply #6 on: 6 Nov 2012, 03:40 pm »
Looks good Bill!

I don't have any engineered drawings of the drivers.

Quote
I know the SW-12-08 is no longer available,

I have three of them left in stock. I can hook you up with a pair of them. No problem.

And welcome to AC.