http://forum.sounddomain.com/ubb/For...ML/000676.html

 

Wow. Very informative thread. BTW, I still have lots of the high-temp mastic sheets from McMaster that I will be adding to my car soon. And they also sell the lead-barrier sheets if anyone's interested.

Stereodude, I'm not very familiar with the comp stuff you are talking about, but I would say that a 20dB reduction in road noise is next to virtually impossible, if not downright impossible. I would say a 3dB reduction would be hella-impressive. I'm talking about driving your car down a certain stretch of roadway at a certain speed and taking an SPL reading of the road noise both before and after whatever sound deadening application you may choose.

If you really want to reduce all the road noise you can, use a couple of layers of the mastic sheeting against every metal body part you can find, with a layer or two of the lead-barrier sheets on top of that. Then use a rubberized spray (Noisekiller, etc) on top of that and it EVERY nook and cranny that may conceivably vibrate or make noise. On top of that, buy the quietest tires you can find (which, depending on how noisy your current tires are, will probably make a bigger difference than all the damping material you can fit in your car).

Anyway, just to set the record straight, unless you want to make a HUGE, HUGE, HUGE project out of sound deadening your car, you are not going to see any real significant drops in road noise. The exception to this would be obvious rattles that can be found and eliminated, and the aforementioned tire swap. Most all sound deadening materials provide you with stunning audio reproduction (when installed correctly) because they reduce vibrations and resonations that add unwanted noise to your music. Think of it as making a speaker box out of your doors, trunk, or whatever else you've mounted your speakers to or in. How good would your home stereo sound if you replaced their speaker enclosures with a thin metal box?

Tony

 

I think you missed and got the wrong thread. Either way no one in that post addresses a material like Lcomp or Vcomp. One guy hints at it when he mentions Defcon foam coated metal mass loading sheet. It works off a totally different method/principal than Dynamat or any of the other damping materials. Lcomp and Vcomp are acoustic decouplers.

I also know I'm not going to get a real 20dB-30dB of NR in the car simply because I can't isolate the drivetrain from the body. But I can cut down on the noise that's coming into my car from the trunk. Which is the goal. When I'm done I'll post some metered measuments of a stock 6 spd vs. mine on the same stretch of road.

Stereodude

 

Sweet. I'd love to see those results. I hope it works well for you!

Tony