How much deadener??

[mrtopnotch561]

Not trying to steal the thread, but most ppl say about 25% coverage is all you need. So then why do I see people double and even triple layering their deadener? At that point isn't it just mass loading that any roofing product coul provide as long as the base layer is quality deadener? I just feel like u would be throwing away money doing that.

25% is a rule of thumb that will cover a lot of car audio enthusiasts.

There only becomes a problem when you try and use dampening material as a barrier, it does that very poorly. I will not recommend anything more than 100% coverage until I see detailed experimentation that proper sound proofing with multiple layers benefits more than it harms. The reason that 25% coverage is optimal is because at that point you get a large increase in vibration dampening, and if it so be that you need to remove the material to work on the car then you aren't out that much, as when the material is removed it will most likely be destroyed.

When sound deadening a car there is much more than just dampening the doors.

There are four steps in sound proofing:

1. Controlling the amount of vibration and resonance with CLD

2. Blocking the air borne sounds with MLV

3. Building a bubble out of MLV with a layer of CCF around 1/8th of an inch think in between the MLV and CLD.

4. Absorbing sound, a good material for this is 3M Thinsulate, the thicker you can make this the more frequencies you can absorb.

CLD: Constrained layer dampening

MLV: Mass Loaded Vinyl

CCF: Closed Cell Foam

Thanks for the detailed explanation.. Sounds like i got some learning and work to do on how to properly. lol