I've been usin 1/4" tile backer board made of concrete and using a thin layer of PVA glue to stick it on. Still being put together so I won't know for another week if it was worth it...
http://www.jameshardie.com/backerboard/homeowner/hardibacker.php
http://www.jameshardie.com/backerboard/homeowner/hardibacker.php
http://www.hsi-luidsprekers.nl/Kastmaterialenonderzoek.htm
Use web-translater from Dutch to your language like this http://www.freetranslation.com/free/web.htm
Use web-translater from Dutch to your language like this http://www.freetranslation.com/free/web.htm
try a couple layers of roofing felt instead -- tack it in there with a power stapler -- decades ago folks were making pads of roofing felt, sand and tar, then tacking to the side of the particle board cabinet -- unfortunately tar stinks when it warms up -- there are acrylic adhesives which will do a good job today.
i did the concrete thing with my second pair of KEF B139 Reflex enclosures -- used 1/2 " layer of Quick-Crete -- to get the concrete to remain in place just drill some #6 pan-head self threading machine screws into the interior of the cabinet -- these will anchor the concrete in place -- and just be patient with the concrete -- doing one side then waiting about 48 hours to do the next. these were the darned heaviest cabinets I ever made and I had to whack them apart with a sledge-hammer when we moved.
i did the concrete thing with my second pair of KEF B139 Reflex enclosures -- used 1/2 " layer of Quick-Crete -- to get the concrete to remain in place just drill some #6 pan-head self threading machine screws into the interior of the cabinet -- these will anchor the concrete in place -- and just be patient with the concrete -- doing one side then waiting about 48 hours to do the next. these were the darned heaviest cabinets I ever made and I had to whack them apart with a sledge-hammer when we moved.
Michail Bugaria said:http://www.hsi-luidsprekers.nl/Kastmaterialenonderzoek.htm
Use web-translater from Dutch to your language like this http://www.freetranslation.com/free/web.htm
I do not want to translate from Dutch to Dutch, but thx for the link now I can read russion sites .Ply wood attached to concrete or masonite board seems to work best. One thing what is not covered by the article is the way the board is attached. Martin only used one constrained sheet for his tests. For cabinets/ enclosures the panel is clamped at the edges.
PVA + concrete sounds like an old wives' tale, but maybe it works to some extent. There's a special epoxy based resin for bonding new concrete to old. It's about the consistency of latex paint when mixed. I used that for creating the final bends of concrete in a Fostex 108Esigma horn. I felt this was a good option to bond the concrete to the plywood (along with screw heads imbedded in the concrete for security) and prevent the water in the uncured concrete from soaking into the plywood resulting in problematic expansion right off the bat. I still maintain that even 1/4" of concrete is simply too brittle to be of any benefit except maybe as a constrained layer.
I've been experimenting with the acrylic gap sealant you get from builder's supply shops. Very cheap. Comes in big tubes. You mix this with builder's sand and a bit of water and you have a very flexible, dense, water-based medium which will stick to anything. You can trowel it on, give it texture etc - may be worth a try.
jackinnj ,
So howeffective iwas it in keeping the panels from vibrating?
"I still maintain that even 1/4" of concrete is simply too brittle to be of any benefit except maybe as a constrained layer."
If you mean constrained layer damping, it sure won't work for that.
The constrained layer needs to be viscoelastic, i.e., gummy,sticky, lossy, etc.
So howeffective iwas it in keeping the panels from vibrating?
"I still maintain that even 1/4" of concrete is simply too brittle to be of any benefit except maybe as a constrained layer."
If you mean constrained layer damping, it sure won't work for that.
The constrained layer needs to be viscoelastic, i.e., gummy,sticky, lossy, etc.
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