Best way to attach cones with foam around screw holes?

Hey all
I’m nearly done with my 2 way speaker with x2 faitalpro 8fe200 and a hf100 CD with sth100 horn!
I’m decided on wood screws to screw the cones into the box, but I’m not sure if I should use silicone sealant with the hard foam around the outer circumference of my woofers, or just screw them in/ use blue tack? I’m assuming I should use it on my metal horn.
Photo attached of said foam:)
Thanks in advance!
image.jpg
 
diyAudio Moderator
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The foam surround is there for mounting behind a baffle. This is common with horn enclosures, but may also be done for protection or for aesthetics. There was a time when it went out of fashion to mount direct radiators behind the baffle, but these days it is accepted if certain conditions are met.

I suppose I wouldn't get messy with the surround unless I had measured the horn impedance and determined that it was not possible to get a proper seal.
 
Thanks for your response! I’m mounting from the front (for ease of assembly…) along with my compression driver. What would I be looking for in my impedance measurement to flag that I should seal it better? And should I measure impedance of my cd, woofers, or vent?
I might just silicone seal anyway for peace of mind, I think it’ll only touch the basket anyway hopefully
Thanks!
 
diyAudio Moderator
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Hornresp should help you with the target impedance. Peaks tend to be suppressed when there is a leak (eg such as to the rear chamber), and horn enclosures are more prone to this than more common types such as closed boxes. You might experiment by deliberately leaving them loose and measuring. You can often tell when left and right are not similar.
 
If the gasket on the rear of the driver in the photo you posted has the same shape as the one on the front of the driver then I don't think you have anything to worry about. As long as there is a continuous run of foam between the baffle and the speaker you should be sealed enough.

Rob.
 
The back foam gasket is somewhat thinner than the front foam one but still more than adequate for the task.

Just screw your speaker in front of, or behind, the baffle board and call it a day, it will work fine.

Don't overthink it and don't use any kind of putty or sealant either.

Some baffle makers used putty because they were mounting NO back gasket frames so they had to kludge something but not the case here.
 
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