I recently have been unimpressed with the amount of road noise and the lack of solid sound my speakers produce.
i currently have Alpine type-s Splits in the front doors to be honest i just thought they weren't as good as they could be. so after some much research on trusty google and talking to some mates at work i decided it was time to sound dead my car.
going into a few shops and talking to some blokes i ended up with a 'Dynamat Extreme' door kit ( 135$ ).
and i must say after applying it to my front two doors the difference it amazing! road noise has gone down around 5-10% but the difference it makes to the sound quality of the speakers is brilliant! Ive noticed a cleaner deeper and more solid bass. before i was skeptical and thought sound deadening/proofing was just a waste of money/ time but how wrong i was!

i would recommend to anyone upgrading there system to use it! its great stuff and if you can get around the price its well worth it!

Yeah, it's not cheap, but the results are excellent.

Yeah its top stuff mate, really get what you pay for.
I got a bulk pack for my car, still have a sheet or two left over.

how much did the bulk pack set you back, im thinking about doing most of the car now

About $220 I think from memory, got it off ebay.
I have my front doors done and my boot and boot lid

http://cgi.ebay.com.au/CAR-SOUND-INSULA ... 19c13bb0cd

Bulk pack