Deadening Material

[daveskis]

I need to refine the design of my almost complete Westminsters.

One addition I think may be worthwhile is material for sound deadening of the rear baffle.(the rear wall of the cabinets)
I have noticed a few suggestions on speaker building threads. So what is the most current and best advice.
This Panel is large about 1265 x 880 28mm MDF with ply outer.

[Reid Malenfant]

Hi David, in all honesty it depends on what you want to damp frequency wise on what kind of material you'll be best off with ;)

I guess it's the rear of the horn but it could well be subjected to frequencies up to 1KHz going on the xover frequency of the Tannoy driver. If that's what you are thinking then Falcon Acoustics used to sell 5mm thick bituminised stuff that would certainly take care of things over say 200 - 300Hz upwards. Below that all you can really do is make the entire panel stiffer, but that raises the panel resonance frequency & makes it radiate midrange even easier :rolleyes:

Similar stuff is used to damp car panels to prevent them vibrating so it's easily available if that's what you are looking for :)

[Welder]

Dum Dum

http://www.ebay.co.uk/itm/400g-Eldro-Dum-Dum-Car-Sealant-Sealing-Compound-/320642456262

I filled my speaker panels with it. It’s a bit of a pig to work with but I haven’t found anything better. You have to build the panels from scratch though; its not a stick on solution ;)

http://theartofsound.net/forum/showthread.php?t=8016

[Wakefield Turntables]

Forgive my ignorance but would Sorbothane be any good??

[DaveK]

Forgive my ignorance but would Sorbothane be any good??

To complement/supplement this question, aquarium and fish pond filter dealers sell sorbothane(?) foam in various grades of foam but having a very two-way corrugated surface on one side - think of smoothed out egg box trays - which might be good at randomly 'bouncing' sound waves in all directions.
The same people also sell plastic matting in various degrees of coarseness, - think randomely uncoiled wire wire welded at each point that it touches - don't know what effect it would have on sound waves but very little would get through in a straight line :lol:
Forgive me if this isn't relevant - I know nowt :) - just thought it might sow a seed somewhere maybe :)
Dave.

[daveskis]

Well thanks guys for all the suggestions.......set my mind to the task.

Of course I could go with Eric's scroll cut jigsaw design, I like the idea of bitumised timber/panels.
I am inclined to try Bitumised Egg Cartons.........should help!