DeTomaso Mailing List: May 2000, Message #1

This has been discussed a number of times before. When the archives (
http://realbig.com/detomaso/ ) get fixed you can search them for more
info. Currently, a search seems to only find posts made in April.

Anyway, I'm planning extensive sound proofing for my restoration (
http://home.earthlink.net/~rbarkley/Pantera ). As Tomas correctly
stated, it takes mass and damping to stop the low frequencies . I'm
planning on covering most surfaces with Dynamat (or similar) materials.
I posted a couple of month ago I found an online source for the Dynamat
Super at about $42/ 12 sq. ft. roll (if I remember). There is a guy on
the net selling what appears to be a commertial waterproofing material
(I think it is WR Grace's Bituthene 3000) that is very similar to
Dynamat and a lot cheaper. Also, I'm installing a dual glass rear window
although I'm not sure how much of a sound source it is.

I also have a roll of Hall's "space age" material. My guess is that it
is used in sound proofing airplanes. It is a small cell plastic foam
with a face of aluminized mylar.  It is a great heat insulater but I
don't know how well it will damp sound. I'll be using it over Dynamat.

In doing my restoration I discovered a number of sound "stethoscopes" as
I called them. The most important ones are the gap between the roof skin
and the above the window structure in the corner just above and behind
the door opening. The gap is about 3/16 by maybe 2" on my car and it
leads directly to the area just behind the gills. Header and engine
noise goes right up there and directly to your ear. The hollow beam that
forms the top of the door opening extends back into the rear roof area
and is open at both ends, so sound can come right on in. I think the
rocker panels are also great conduits for sound. I plan to put dynamat
on them in the cabin and in the engine compartment and to somehow seal
off the hole with the wires.

How well will all this work? Don't know. But I made some recordings
before I started my project and also measured the sound levels with a DB
meter. I will be able to do spectral analysis and compare the
before/after levels.

Good luck with your project


Richard Barkley


> Anyone ever endeavor to reduce cockpit noise and heat through insulation or 
> sound deadening materials?...I would like to retain the sound of the car 
> outside yet make an extended trip potentially  less exhausting with a much 
> quieter interior..I thought of doing the ENTIRE interior 
> (firewall,doors,bulkhead and roof and even the roof posts!!) with Dynamat 
> material and perhaps the kit available from Hall Pantera that is some space 
> age material designed to reduce heat and noise...anyone attempt something 
> like this?..were the results significant?....Thanks in advance!
>