# Forum Home Renovation Home Theatres  Rythmik Subwoofer

## Sterob

I bought one of these amps and 15" driver a couple of months ago. I have yet to start building the enclosure. but  I was wondering if others had one of these Subs and what they thought of it.
Did you use the provided box design or use something else?
I'm sure it will do the job for my home theatre.....
Steve

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## Cecile

> I bought one of these amps and 15" driver a couple of months ago. I have yet to start building the enclosure. but  I was wondering if others had one of these Subs and what they thought of it.
> Did you use the provided box design or use something else?
> I'm sure it will do the job for my home theatre.....
> Steve

  I'll let Moondog know about this post.

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## Moondog55

Those subs have a very good reputation.
If it is the dedicated Rythmic driver I would use the box design they provide.
If you post the T/S parameters and the box design i could check it for you if you want.

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## Moondog55

IF THIS IS THE PLAN  http://www.rythmikaudio.com/download...s_sub_plan.pdf 
Use 16mm plywood and 20mm MDF for the second baffle on the front and you will not do better, although I would be adding 20*20 glue blocks in each corner if you plan to crank up the volume

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## Sterob

Hi Moondog,
Thanks for the input. I was thinking of using their Ported design. I'll have to convert their imperial dimensions to metric though as I am a metric baby..... 
Have you seen/heard any of their designs? 
 I bought the amp and driver purely from internet comments I have read and a couple of U Tube vids.   
Steve

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## Moondog55

Ported box usually has lower WAF due to the larger size but if you have the space it will give you +3dB and greater bass extension, just make sure you have the subsonic filter on the amp switched to the *ON* position

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## Sterob

> Ported box usually has lower WAF due to the larger size but if you have the space it will give you +3dB and greater bass extension, just make sure you have the subsonic filter on the amp switched to the *ON* position

  Ok...good to know. Thanks! I think I do have the room for it so it will be good. 
Steve

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## Moondog55

If using this design  http://www.rythmikaudio.com/download...v_sub_plan.pdf 
i would use the option of flared ports to avoid compression and chuffing, flared ports make a huge difference, I think Collo still sells flares.  Collo's DIY Subwoofer Enclosures 
 check out some of his monsters while you are there

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## Sterob

> If using this design  http://www.rythmikaudio.com/download...v_sub_plan.pdf 
> i would use the option of flared ports to avoid compression and chuffing, flared ports make a huge difference, I think Collo still sells flares.  Collo's DIY Subwoofer Enclosures 
>  check out some of his monsters while you are there

  I'll certainly be fitting flared ports, thanks for the info. How critical is the ID of the port? Is slightly larger ok ? 
I only went with the 370W amp as I don't think I will be wringing its neck in the HT duties.
Steve

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## Moondog55

ID of the port is critical to that particular design.
With ported boxes every aspect of the design is critical to design performance, if you change one aspect you have to recalculate everything else, if you go bigger with the ID of the port tubes they will need to be shortened. Same thing if you added more port tubes. It is why I usually only build sealed boxes, hard to make a suicidal mistake and difficult to make a sealed box too big, the extra bass extension and the extra 3db ( +3dB is equal to doubling amplifier power after all ) is worth it for most people tho and these days it is easier to get a decent driver designed and made for ported boxes.
3inch PVC tube ?? Just use 75mm for this application the ID is close enough and you can get it everywhere, even Bunnies sell it

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## Sterob

When building this enclosure, do you think it would be ok to just glue the parts together( with a quality wood glue) and staple with a pneumatic staple gun? (assuming I can use long enough staples? )
The notes for the Rythmik boxes say don't really need screwing together. Just wondering what your experiences are.
Maybe the stresses on the box will prohibit such a fool thing....

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## Moondog55

While I usually use brads to maintain alignment of the edges, I have never needed to use screws unless there was no way to clamp the box.
I use PVA wood glue, the outdoor grade unless my cut edges are a little rough in which case I use a mixture of that plus some "Quick grab", it is important not to clamp to tightly when using PVA which is why the IRWIN clamps are good.
Which material are you using for the box? If MDF make sure you use the MDF type of PVA glue. 
I am green with envy, I love deep bass LOUD

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## Sterob

> While I usually use brads to maintain alignment of the edges, I have never needed to use screws unless there was no way to clamp the box.
> I use PVA wood glue, the outdoor grade unless my cut edges are a little rough in which case I use a mixture of that plus some "Quick grab", it is important not to clamp to tightly when using PVA which is why the IRWIN clamps are good.
> Which material are you using for the box? If MDF make sure you use the MDF type of PVA glue. 
> I am green with envy, I love deep bass LOUD

  I'm using MDF for the box. Thanks for that. I should be able to get good fits as I will be using my triton table saw.
Will check out that glue.  I have stock PVA as well as a PVA from a specialised woodworking shop.

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## Moondog55

If using MDF you really do need to use the MDF specific MDF glue, it contains a solvent for the wax coating on the exterior of the MDF.  
What I have done in the past is use a mixture of plaster crack fix ( the stuff with the cellulose fibres mixed through ) and that PVA glue coated all over the inside where there are joins rather than sealing with silicon. Remember this has to be absolutely airtight to +11PSI for the box to work as designed

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## Sterob

> If using MDF you really do need to use the MDF specific MDF glue, it contains a solvent for the wax coating on the exterior of the MDF.  
> What I have done in the past is use a mixture of plaster crack fix ( the stuff with the cellulose fibres mixed through ) and that PVA glue coated all over the inside where there are joins rather than sealing with silicon. Remember this has to be absolutely airtight to +11PSI for the box to work as designed

  
I'll look into that .
11 psi...wow....thats huge. I didn't realise the pressures were that high.  
I think I'll buy a Brad Nailer. I don't think the staple gun will cut it and they are cheap enough. I reckon it will speed up the fabrication alot.

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## Moondog55

Well to be honest I got that figure from a different forum where the owner was using a 1500 watt amp with massive bass EQ, but it sounds about right. 350 watts might reach 3PSI

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## Cecile

Only another crazy speaker-builder would understand "WAF" 
Still makes me grin.  Moondog will tell you that he's got pretty good WAF (mostly because he had much of his gear before we met  :Tongue: )

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