| | lsiberian
has a very good article on the subject and suggests using 30 lb. roofing felt.
I'm wondering if any of you have experiences with constraint layer damping in loudspeakers.
The gentlemen measured a 20db decrease in panel vibrations which I found impressive.
I remember the old Ludwig build, but hadn't read it in ages. My first thought reading your initial post was 'what the is 30lb roofing felt?'. Turns out we have a similar product here called Malthoid dampcourse which is about $A13 for a 100mm wide 20m roll so I think I'll give some a try in the speakers on the interior walls. Not sure what to glue it to the walls with though. I've emailed and enquiry over the w/e and hope I'll get a response.
Vann's post 2 is my understanding of CLD (better expressed too).
| | vann_d
I've also thought about using honeycomb sandwich panel construction but the cost seemed to outweigh the benefits. Maybe a foam core sandwich panel could be constructed DIY and really help reduce the weight of the cabinets while maintaining excellent panel stiffness. The foam core may act as a damping material in the process.
Many years ago, about the time of the SL600 Celestions, a friend built some speakers and subs with a Styrofoam core and Laminex skins. It was very light and stiff and seemed to work well but we had no way of measuring back then. Each skin was added over the 50mm thick styro and left to dry. Panels were cut and mitred and glued to each other to form the enclosure. The baffles had marine ply behind the drivers to give extra support.
The speakers were huge, a big 4 box sort-of line array a la Infinity IRS.