Fire Extinguisher

[kaanage]

I've tried lining the wheel well etc with carpet underlay and the difference was minimal. I notice extra noise even with just the rear shelf removed.

[noone]

carpet unerlay is not a noise barrier.

Have a read on noise treatments, some absorb, some block. I used something like dynamat, but cheaper and a 6mm medium density closed cell foam, as a barrier. Made a big difference. Used it on the passenger side floor, in front of the doors, cover where the cables for the doors pass through, the hole behind the side mirror. I used the dynamat like stuff to add mass to large resonating panels and blocking cable access holes, etc.

Over all, made a huge difference, but I think to get a reasonable result, you've got to be willing to spend atleast a day and spend atleast $100 and well upwards to get it done well. I added about 6kg to my car, happy with the results, even the stock speakers in the doors sound better.

[kaanage]

It works fine for some frequencies but obviously not the ones in cars (and I'm using the heavy duty industrial stuff, not the cheap, çrappy eggshell $hit that they supply for free with your carpet install).

I have a friend who builds speakers as a business and he uses the same carpet underlay (amongst other materials) to dampen internal reflections in his cabinets.

BTW If you use a subwoofer and and head unit/amp that allows bass redirection, you don't need to line your doors. Nobody can understand the sound quality in my car after I tell them that the drivers are stock but the bass has been removed from them.