| Re: Sound deadeners |
Subject: Re: Sound deadeners by BillH on 2012/11/8 14:40:39 Quote:
I'd come over to colorful Colorado, I spent almost 3 years there racing motorcycles, er, going to collage. The vettemod kit is worthless, no foil. The other 2 kits look pretty good. One of my jobs at Ingersoll-Rand was "sound control engineer" trying to quiet down construction equipment at a time when no one else was doing it, - not easy. I did use close cell foam with doublesided foil in the engine compartments, it worked well on higher frequencies, so I like these kits for some of the road/wind noise. I think you have to separate exhaust noise/resonance from the road noise. Exhaust is at lower frequencies and an exhaust system also vibrates thus the resonance. And I agree that the rear of a C4 underneath the car has a lot of spaces that will act like a base speaker cabinet. So, if you want to keep the current exhaust system, the only thing you can do is change the mass of some of those panels so that they vibrate at a different frequency - the bed liner Andy mentioned or maybe undercoating. Or change to Corsa, their engineers must a boatload of time working on the resonance thing. The exhaust thing would take a lot of experimenting. Your custom rear valance may be contributing somewhat, it would be interesting to pull it off and see if anything chances. |
