So I now feel like I know more than I ever wanted to know about sound proofing versus sound dampening etc after a few hours on the web and talking to carpet people!
I have very loud mufflers/exhaust (Flowmaster Series 40) and trying to improve the internal noise before I decide to change them!
So spent time putting very heavy sound proofing under back seat , behind rear qtr trim panels and boot. Huge dissappointment in the noise reduction as it seems to be very small considering the quality of the underlay.
Anyone else had any experience at trying this?
Is there a favourite noise spot? Am I wasting my time? Does the sound come through windows/roof and sail panel areas or through the door?

Sean
some pics:

Good Day. Had the same problem. I ended up using a product called Damplifier. Installed in trunk area fender wells ,sail panels and inside quarter window panels also total floor area from firewall back. Result was less road noise and muffler noise. In all I was perrty satisfied with end result. Material has a sticky back and once put on is hard to remove. Install when warm and if possible leave it in sun to warm, heat gun works well also. Don't let this scare you,even I managed a decent job of it.
Where I ordered it from it was available in 80 square foot pck. This did entire above mentioned and I still have several sheets left. Use mettalic sheet metal tape to finish the seams and that does a nice job, as finish on the Damplifier is silver. Has good heat resistance and does not seem to hold moisture. I would post pics but can't seem to figure out how to do it. Hope this helps.

Thanks Dearborn,

Sounds like I should persist. I expect the product is not the problem as it is highly rated locally but I have not done the sail panels and only up to the rear seat on the floor. So this may be worth looking at.

The way I posted pics was the image button then http:... of hosting server then image button again. The text looks somethin glike:


Thanks for your info that gives me some heart to contniue

I used Dynamat. Its expensive and I have no way of comparing it to before & after. I only ever drove the car with it installed.
I've got to say I am impressed. My car is loud but not excessive and you can still have a talking conversation inside at 60 mph.
I didn't expect that. The heat side of things is OK but after 30 minutes there is some engine heat coming back to the cabin.

Hi Sean. Looks as if you have installed the felt underlay. Roughly 10mm thick. Not to disappoint all the Ford fans, I have just finished a 67 Camaro, running a B/B 502, 3" Pipes. The entire floor, firewall, inside quarters, basically any where that I could insulate, I did. The product is called Road kill. Looks very similar to the Dynamat shot. This is aluminum foil backed both sides sandwiched with bitumen. Works great, Google it. Cheers

Hi Guys,

Yep Slamming a bit of a mixed bag actually. Started with the felt and bitumen type underlay in some areas then got a heavy duty soundbarrier with underlay for under the back seat. Now that my carpet and seats are out (currently re-covering them) I have bought a product called DBKill which is similar to your roadkill and also dynamat. Just managed to get it locally with a better price. I will post some more pics once I have installed more.
I also used a sound dampening/speaker box type material in the doors. This was the biggest gain of all the work. It was very light weight but seems to have absorbed a lot of the 'booming' type noise so the doors obviously act like speaker boxes once exhaust noise gets in- don't miss this step as it was the best reduction so far

cheers

Sean