Sound Deadening, A little more technical question Options

[r_towle]

Hi,
I have been reading lots on the Internet, and the more I read, the more I find that no-one has done any real analysis.

What type of sound does a motor make?
Is it vibration, or soundwaves?

I guess what I am looking for is not the Use Dynamat, Use Brown Bread type of answer.

What if I combined both the ceramic spray on products, and the peal and stick products?
Aside from throwing alot of money at the problem, am I really stopping any more sound waves from coming through?

Are there any discussions of what sound waves Dynamat stops, and what sound waves a spray on ceramic sound deadening system stops?
Are they the same waves?

It seems to me that when you use two of the correct products, each designed to stop a certain type of sound wave, you will get a much better result.

But, where is the info telling me which sound wave is stopped by what product?

Rich

[Twystd1]

Tony... You be one smart sunofagun.

I am a firm believer in using the two layer method. Any of the Tar like dampers. (Bitumen, as per Tony) for the first layer.

And where possible, a second layer of closed cell neoprene. Much like wet suit material but stiffer and having a smaller celled structure. I buy 2' X 3' remnants from a place called AA yardage in Santa Ana, California. They cater to upholsterers.
I install it with 3M spray glue #77. Works like a charm. You can also put dynomat OVER it if you choose.

If you have any neoprene at home... Go set it on the hood of a car and give it a tap. It will kill a bunch of resonance pronto. It both absorbs and deadens. And turns the sound to heat.

If ya get hardcore. You find EVERY hollow space you can, and spray in NON EXPANDING spray foam in hollow spaces. This really helps keeping the
sympathetic resonance effect to a minimum.

This has worked for me many times. Just more stuff to think about.

Clayton