sound deadening review and stickied?

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.