Skin Effect.
Only significant for high frequencies - e.g. at 10k Hz skin depth is ~0.65 mm
At motor frequencies, 100-200 Hz max, skin depth is couple milliliters - nothing to worry about.
Yeah, looks like it got good reviews from people.
Though even at Lowe's price, dollar per pound, it's not that much cheaper than specialized deadening stuff - like 70% or so.
Deadening sheets are very heavy and that's their main quality that works.
The foam that you linked is completely different animal.
It's not my, I wish! :D
But I used that thread as my how-to back in 2012 and I like how it worked out and lasted all these years.
Foam is used mostly to fight...
Anything will be better than oem coffee filters even with all noise our cars make!
I have Boston Acoustics Pro60SE (now discontinued), only issue was freezing cones in cold Chicago winters.
In general, I'd suggest component speakers that have tweeters mounted separately in doors window corners...
Unlike standard heat range, one step colder NGK's ground electrode is just nickel and not platinum tipped, so they wear faster.
NGK specs say 40-50k vs. 80-100k miles longevity. So, for our upgraded cars you can use 50% of these intervals.
There is some daily driveability that may to be affected and emissions concerns - do your research.
If you do not see anything obvious, then you may try to swap that black control box that sits on the top of IM.
Many people have them laying around from deleting VTCS and will sell for just a...