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

[McMark]

So Ken, do you think adding some material to a stock rain tray would qualify as:

allow the sound to vibrate a mass. The mass is suspended on a spring (foam sheet or dampening sheet)) and the sound energy vibrates the mass, and the spring or (dampener material converts the vibration to heat and dampens the noise

[Katmanken]

So Ken, do you think adding some material to a stock rain tray would qualify as:

allow the sound to vibrate a mass. The mass is suspended on a spring (foam sheet or dampening sheet)) and the sound energy vibrates the mass, and the spring or (dampener material converts the vibration to heat and dampens the noise

Mark, the answer is it depends on the materal and what you hope to solve. If you hang the tray from dampeners (such as springs), then the mass of the tray will transfer the vibrational energy to the dampeners. If you do that, make sure that one end of the "spring" attaches firmly to the engine lid and the other end attaches firmly to the rain tray and there is no fastener coupling the lid and tray together. I also think the stock tray qualifies as a large vibrating panel so adding a layer of dampening material (on the bottom) would help with that. The tray also seems ideally placed for a sheet of closed cell (non water absorbing) foam on the bottom of the tray (or the dampening material) to absorb motor noises.

These EAR guys make great dampening material and now foam. The "blue" vinyl materials and grommets are awesome. One of the aftermarket vendors is selling them with their non stock tranny mounts and I spotted the blue color and thought that it was a great use. The grommets, if used correctly can be used for the rain tray.

EAR site

Ken