andy2 said:
Generally speaking in 2005, afaik, you can't purchase *anything* with lead in it, except for solder - and that is going away too...
There are some materials that use a high lead content for x-ray protection, and these can be acquired from professional sources.
Why do you think you want "lead bitumen" sheet? And what do you think you want to do with it??
I'd say to consider some other solutions to your "problem" like constrained layer damping techniques (taking a guess at your intent)
_-_-bear
You can buy 6 lbs. sheet lead in almost any roofing supply store. Comes in about 30" square pieces and weighs a ton. It is used in bituminous built-up roofing. I've never heard of lead bitumen sheet. Can you elaborate a bit?
Cal
Cal
I've never used them myself but after reading from Troel's website, it seems like he uses them in his speakers. So I thought I might try it out myself as soon as I can find a place to purchase them.
If I understand correctly, they are used to pad the side panels to reduce vibration.
If I understand correctly, they are used to pad the side panels to reduce vibration.
... and they're nuclear radiation proof! 😀
you might do just fine using the sheet, assuming you can get it from a roofing supply still, and putting any one of a number of roofing adhesives or other adhesives between the sheet and the wall of ur cabinet, I suspect.
Roofing "mastic" comes to mind, as does one or more of the acrylic roofing "mastics"... a final coat on the outside of the lead (inside of the box) should make it work fine... (the acrylic/latex products clean up with water)
There are a number of interesting heat activated roofing materials that will also do a fine job of damping a cabinet wall.
Also, the double wall, sand filled method a la Warfdale is worthy of consideration too...
And the constrained layer method... which is somewhat less messy than most roofing stuff...
_-_-bear
you might do just fine using the sheet, assuming you can get it from a roofing supply still, and putting any one of a number of roofing adhesives or other adhesives between the sheet and the wall of ur cabinet, I suspect.
Roofing "mastic" comes to mind, as does one or more of the acrylic roofing "mastics"... a final coat on the outside of the lead (inside of the box) should make it work fine... (the acrylic/latex products clean up with water)
There are a number of interesting heat activated roofing materials that will also do a fine job of damping a cabinet wall.
Also, the double wall, sand filled method a la Warfdale is worthy of consideration too...
And the constrained layer method... which is somewhat less messy than most roofing stuff...
_-_-bear
Hi bear,
Lead sheet is still widely available (in Canada anyway)
Mastic's won't work as adhesives. You will have to mechanically fasten it.
Also, the solvent count in mastics is too high. The gas-off would be just horrible and possibly detrimental to the drivers.
Not familiar with the acrylic/latex products you are calling mastics. In my part of the world, mastics are asphalt based.
The only heat activated roofing materials I can think of are the modified bitumen roll systems like SBS and APP and the plastic ones like the TPO's ie😛VC or polyolifins. I can't see the value in these. Do you have some product names or descriptions?
I think your suggestion of the double walled, sand filled idea is the best.
I did use lead sheet in a system years ago but it has some holes punched in it and was hung down the centre of the cabinet. Heavy and impractical.
Cal
Lead sheet is still widely available (in Canada anyway)
Mastic's won't work as adhesives. You will have to mechanically fasten it.
Also, the solvent count in mastics is too high. The gas-off would be just horrible and possibly detrimental to the drivers.
Not familiar with the acrylic/latex products you are calling mastics. In my part of the world, mastics are asphalt based.
The only heat activated roofing materials I can think of are the modified bitumen roll systems like SBS and APP and the plastic ones like the TPO's ie😛VC or polyolifins. I can't see the value in these. Do you have some product names or descriptions?
I think your suggestion of the double walled, sand filled idea is the best.
I did use lead sheet in a system years ago but it has some holes punched in it and was hung down the centre of the cabinet. Heavy and impractical.
Cal
I use lead bitumen self adhesive panels in all my projects.
Great deadening properties and widely available here in the UK from Wilmslow and Falcon Audio. Another goodie is the Spectra Dynamics Deflex - expensive for what it is though and no more effective than the dedshete(lead bitumen) panels I use.
Great deadening properties and widely available here in the UK from Wilmslow and Falcon Audio. Another goodie is the Spectra Dynamics Deflex - expensive for what it is though and no more effective than the dedshete(lead bitumen) panels I use.
The heat activated roofing I've seen is thick, self adhering and looks very much like it will do well at damping... dunno what systems are out there, or how practical it might be on a wood box... seems possible.
Carpet felt is very effective at absorbing HF down to fairly low freqs depending on thickness and means of application.
I find it to be indespensible for midrange cabinets and woofer boxes that run into the midbass... ymmv.
Don't think it is optimal for LF cabinet wall damping.
_-_-bear
Carpet felt is very effective at absorbing HF down to fairly low freqs depending on thickness and means of application.
I find it to be indespensible for midrange cabinets and woofer boxes that run into the midbass... ymmv.
Don't think it is optimal for LF cabinet wall damping.
_-_-bear
andy2 said:
Carpet padding won't do much, if anything, to damp speaker cabinet walls.
Lead and/or bitumen are very good damping materials. I have not seen "lead bitumen" sheets here in the US but I have used both lead sheet and Aluminum foil backed "roof repair tape".
I agree that a double wall cabinet with sand between the walls is excellent sonically, though you'll end up with large and heavy cabinets.
I would like to know where to get lead bitumen sheets locally here in Ohio.
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