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Originally Posted by itsfun
Thanks for the write up. I'm planning on deadening my BRZ doors and am using SoundDeadenerShowdown.com as my source of info. Understanding the difference between CLV vs. CCF vs. MLV was like climbing a mountain, altough in the end it's relatively simple stuff. I always thought sound deadener was a "one item conquers all" thing (no doubt due to dynamat marketing) so the biggest hurdle was understanding there are different items for different applications.
Sounddeadenershowdown talks about MLV (mass loaded vinyl) being the major sound deadening contributor. Is there a reason you didn't use any MLV in your setup? Was it weight savings since MLV is usually the heaviest of the three products (1lb per ft^2)? Was it because you aren't really trying to "sound proof" the door but "deaden" it? Not trying to poke holes in your plan just trying to learn.
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It's a lot to put your brain around... it's not the easiest thing to put into words either. maybe some analogies might help you with how they are working to block sound.
- CLD works as an absorber... it takes vibration and changes it to heat which is why there is a layer of foil to radiate the heat away from the butyl. It is the "Deadener" because it does not allow the metal to resonate or vibrate at the same frequencies.
- CCF works as a filter. It prevents certain frequencies from passing through it, but does not block or reflect sound.
- MLV is an actual "blocker" actually prevents a large range of frequencies from passing through. The way it does this is that it provides a layer that is so dense and elastic, that it doesn't vibrate except at a very low frequency.
So technically all 3 of them perform different tasks as far as sound proofing goes. The CLD dampens the metal panel so it does not vibrate in resonance with the sound and transmit it fully, the CCF filters a lot of the harsh higher frequencies that intrude into the cabin, and the MLV blocks the lower frequency. Each does their part, so even if you combine 2 of them, there is significant improvement.
With Mass being an enemy to these cars, taking a minimalist approach means that I wanted to get the best benefit for the least weight gain. Adding MLV such as Second Skin's Luxury Liner would've added another 7 lbs to each door and tripled the weight increase of my modifications.
Shankenstein, I like the Speaker Tweakers, I used them in my Si and there was a noticeable improvement after I added them, so I naturally just added them here. I think it helps to break up the back wave and makes the air compression by the speaker more distinct. I think it probably has a huge hand in cleaning up the "mud".