Need simple solution to decouple driver from baffle

Home Theatre Systems

Fiftyfifty

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Hi

I'm trying to build a single driver open baffle speaker using AN 12" Super Ferrite drivers. The baffle material will be 1.25 inch Steamed Beech. I'm convinced of the merits of decoupling the driver from the baffle. I was wondering if I could mount the driver on a fabricated mass loaded steel fabricated stand. The air gap between the rim of the driver and the cut out in the baffle could be closed with felt or double sided tape?Alignment can be tricky but IMO manageable.

I'm a beginner at this and would love to get design ideas to take this forward.

Thanks a ton in advance.

PS: Request you not to send your opinions on the merits or demerits of decoupling. What I specifically need are design ideas using wood and steel to achieve decoupling.

@yogibear @sadik @jmascreen @Kannan
 

Sumanta

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I think this idea will work.
Hold the driver on its magnet or basket, whatever works for you.
Use synthetic clay (children play with these clay) to fill the minute gap between back side of the rim of driver and front side of the baffle.
Additionally, only if the gap is really more than few millimetres, you can have a thick flex somehow cover the clay and also stuck on both back face of the rim and front face of the baffle will seal the gap nicely yet keep the resiliency to counter driver vibration movements.

I will think on it more, and will come back with a drawing if I can get it sorted in a better way in my head.
 

Fiftyfifty

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I think this idea will work.
Hold the driver on its magnet or basket, whatever works for you.
Use synthetic clay (children play with these clay) to fill the minute gap between back side of the rim of driver and front side of the baffle.
Additionally, only if the gap is really more than few millimetres, you can have a thick flex somehow cover the clay and also stuck on both back face of the rim and front face of the baffle will seal the gap nicely yet keep the resiliency to counter driver vibration movements.

I will think on it more, and will come back with a drawing if I can get it sorted in a better way in my head.
Thanks Sumanta,
I find a few people use Sorbothane, but couldn't find it on any Indian site. I was considering using a gasket made of 5mm cork. Do you think clay will be superior to cork, or clay + cork?
 

Kannan

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Cork will disintegrate. Some options include rubber gasket (check parts express), mutiple layers of rubber tube or a piece of tire cut to shape. Finally closing edges with rubber sealant (commonly called silicone)
 

Fiftyfifty

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Maybe I can just use rubber pads and stick them to the rim on one side and baffle on the other without screwing through. Multiple pads around the rim better than single gasket for vibration control
 
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Fiftyfifty

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This method from Hawthorne Audio appears simple and doable:
When building our production finished speakers we mount our drivers first to a plywood mounting plate. This plate is 16.5 x 16.5 inch and we bolt our drivers to this mount using 0.25-inch 20 bolts, washers and finally Nylock brand locking nuts. This seems to do a great job of arresting any ringing of the outer driver flange and stiffens everything up nicely. Very Rigid once mounted to these mounting plates. We then insert a thick, foam rubber gasket between these mounting plates and the back side of the baffle proper. We then bolt these plates to the baffle with this gasket serving to decouple the two pieces of wood. This does a good job of limiting the direct transfer of vibrations from the driver to the baffle.
 

Hari Iyer

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@Fiftyfifty
This is what I did for my OB speaker,
- stick double sided tape on the speaker rims (only one side of double sided tape was stuck, the other side was not peeled).
- placed the drivers on the baffle and while placing my screws, I isolated the drivers from the baffle by placing rubber washers under them. The drivers were already isolated below by the double sided tape. The rubber washers were one that we use for our water taps :)

This gave me close to 95% isolation, did not burn my pocket.
 

Fiftyfifty

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@Fiftyfifty
This is what I did for my OB speaker,
- stick double sided tape on the speaker rims (only one side of double sided tape was stuck, the other side was not peeled).
- placed the drivers on the baffle and while placing my screws, I isolated the drivers from the baffle by placing rubber washers under them. The drivers were already isolated below by the double sided tape. The rubber washers were one that we use for our water taps :)

This gave me close to 95% isolation, did not burn my pocket.
Simple and effective! I'm tending to go by the Hawthorne method - also quite simple
 

keith_correa

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This method from Hawthorne Audio appears simple and doable:
When building our production finished speakers we mount our drivers first to a plywood mounting plate. This plate is 16.5 x 16.5 inch and we bolt our drivers to this mount using 0.25-inch 20 bolts, washers and finally Nylock brand locking nuts. This seems to do a great job of arresting any ringing of the outer driver flange and stiffens everything up nicely. Very Rigid once mounted to these mounting plates. We then insert a thick, foam rubber gasket between these mounting plates and the back side of the baffle proper. We then bolt these plates to the baffle with this gasket serving to decouple the two pieces of wood. This does a good job of limiting the direct transfer of vibrations from the driver to the baffle.
As an extension to that, one can sandwich the driver between 2 layers of baffle with no hardware used to mount the driver. Only the sandwich with appropriate isolating material in between holds the driver in place.
If bolts/nuts/screws are used to mount the driver you're coupling it again. :)
 

Fiftyfifty

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Sold out

As an extension to that, one can sandwich the driver between 2 layers of baffle with no hardware used to mount the driver. Only the sandwich with appropriate isolating material in between holds the driver in place.
If bolts/nuts/screws are used to mount the driver you're coupling it again. :)
Absolutely agree! The only problem is that I have just a single layer of baffle. My board is 1½" thick
 
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