sound deadening review and stickied?

Rockhound

That's probably because most of these products mentioned are just the dampening layer. I found that out the hard way in a previous car. Loading up on a dampener material is going to be disappointing as it is just one of three layers needed to cut down sound waves.

A three layer approach is the most effective at sound deadening; you need a dampening material first, which is what almost every 'dynamat-esque' product is. This layer primarily reduces panel resonance, but lacks the mass to effectively reduce noise, it's just the physics of sound propagation - and a little goes a long way. Second you need a buffer layer of closed cell foam. On top of that you need a barrier of something with some heft, like mass loaded vinyl - this is a crucial layer for significant reduction.

I did tons of research on this stuff anticipating needing it in my Z that was on order, but after owning it a year I've been fine with the noise levels. One helpful website I found for this stuff is Sound Deadener Showdown - this guy has put together a fantastic breakdown of each layer and the reasoning behind it.

http://www.sounddeadenershowdown.com/


Sent from my SGSII using Tapatalk 2

DrNumbers

While this website was an interesting read, I feel like it's a bit misleading at times and ends up being misinterpreted. This guy says that 25% is the optimal coverage for CLD tiles, but I think many people end up covering 25% with other types of products (i.e. dynamat, noico, gtmat) which are more akin to the CLD sheets that he sells. In fact, he notes that more CLD sheet is needed to match the performance of CLD tiles. How much coverage though is not stated, as his CLD sheets are meant for 100% coverage to protect from corrosion.

He doesn't show any test to say that 25% coverage is optimal. I watched the video on youtube, and pinging a steel sheet with and without CLD tile is not a real test. All he showed is that 25% coverage does something. I will say that the difference was impressive, but still nothing to back up the claim of 25% coverage being optimal.

I think the other thing is that his website is really focused on blocking sound as opposed to vibration/rattles. In that regard, I agree that layering sound deadener to reduce sound is not effective. I'm curious as to how well 25% coverage would reduce door/hatch rattles in the 370z resulting from mid-bass or subs hitting. I'm not convinced that using high coverage of dynamat/noico/gtmat is useless for mitigating rattles. There are certainly diminishing returns though.

This begs the question - Optimal for what? Is cost effectiveness part of that equation? If we don't care about cost, and our goal is for example, elimination of sub rattles, I think that optimal point changes. Maybe we don't need 100% coverage or double layering, but I think there's a reason most SQ/SPL competitors go heavy on the coverage besides being misinformed. Ultimately, I think going 25% coverage with most sound deadeners is not going to be very effective in reducing rattles. There was a clear difference in tapping on my doors with low coverage and high coverage.

All in all, still some good info in there, but I've seen a lot of people (on audio forums) misinterpret what is actually being said.

markesc

Agreed.

I'm going to just take the experimental approach, not like one cannot remove the door panels again and try something different/add later.

Just saw on this channel: https://www.youtube.com/user/CarAudioFabrication/videos

this video: https://www.youtube.com/watch?v=h3EXuHlBy4M

Looks like he uses different layers of different types, and custom plastic panels to cover the window service area opening, while still allowing them to be unscrewed/removed if the window ever needs replaced. Top notch work! (great excuse to buy all kinds of tools).

Off topic, but I read somewhere people complaining about the bose system, here is an Audio Control amp that is in my opinion future proof for any vehicle moving forward if you want to keep the stock deck. NO remote turn on wire needed and you get an extra set of line outs for future sub amp add ons: https://www.youtube.com/watch?v=flz6sq1dCuk&t=4s They also have a dsp that's just sweet!

The idea is it eliminates the need for a line/level converter, as everything is built into the amp. An INSANE amount of flexibility. Probably going to be the way everyone will have to go in the future with this hobby as oems come up with new ways to over complicate things and give us bs we don't need/want.

I found this helpful as well: https://www.youtube.com/watch?v=308ueFVOylU

markesc

wow 15 sq feet GTMAT Quadro Pro didn't go very far!!!

Upon advice from others, decided to tackle the rear trunk area first.

Before:



After:



Did whole sheets around the shock towers in hopes that it will reduce some of the freakin tire noise! Also did the back section not seen in the photos, but I'm positive that's where a lot of the exhaust noise comes from. Instead of doing the blanket cosmetic approach, I tried this time by focusing on areas that actually needed it as it's not a Ferrari/Bugatti/etc.

What shocked me most was just banging around and realizing that there are so many areas where it's simply tinny metal!!!!

So far I can tell an immediate difference just re-parking the car back into the garage!

Question:

I noticed there's a gap in the fender area that you can fit your hand in quite a ways on the drivers side, and not so much on the passenger side. Has anyone tried any sort of expanding foam sound deadener in these two particular places?

Will order some more and not sure if I should do that small area where people put their aftermarket amps, or if the doors would should take priority?

Appreciate everyone advice on this! I'm late to the party however, 3.5 years of ownership and just now doing this...

Attached Images

	IMG_2298 email.jpg (201.2 KB, 159 views)
	IMG_2299 email.jpg (380.4 KB, 174 views)