This is getting complicated. The more I read on Ethan’s page, the more confused I get. My lil project is on hold till I can figure this crap out a bit better. I’m not even sure I can use the fabric I bought. Ethan says you should be able to blow threw the fabric with relative ease. The stuff I bought takes effort. So if I use it, it will reflect high frequencies. Not sure if I want that to happen, it doesn’t sound good.
There’s deep bass, mid bass, high bass, mid-high frequencies. All require different trap building techniques.
I had an interesting (to me!) experience at an NBA game on Wednesday. Sitting in the nosebleed section, I was able to see the speaker array used, up close. To my surprise, it was not of the normal rock band size. Not small, but not what I remember from Van Halen or Metalica concerts.
But, even in this massive open and hard sided arena, the bass at my seat was solid as a brick to the gut (call it bowel shaking
), with no thunder decay or muddiness at all. The more I paid attention, I was surprised that the music was very solid and clear, the announcer’s voice was clear, and there was no echo at all, despite the cavern of cement under a steel roof.
So I started to look for the acoustic secret – and I found it. First, human flesh. There was lots of it. But more importantly, I think, from the ceiling they had large rubber mats, suspended in a weak U shape. Lots of them. That was all I could see after close scrutiny. That got me thinking about some of our discussions here about the need to be able to blow through the material, the depth of insulation, etc. Relatedly, it reminded me of the well accepted use of sound deadening material on the auto side.
I know “those bass heads” have nothing offer true audiophiles (even if half the people on this thread have more subwoofers than 80% of those "mobile" bastards), but I have used several products to kill the road noise in my SUV, with exceptional results. Those products, like the rubber mats at the arena, use a rubber or tar based membrane to convert sound energy to heat. These products are less than a quarter of an inch thick, and the rubber mats at the arena were no more than an inch thick (and about 3 feet wide).
Why then, in the more heady home audiophile realm, are we constantly talking about compressed fiberglass 12 inches thick to kill a bass note or stop an echo? Has anyone seen a study of the acoustic properties of thin rubber and tar membrane products as compared to fiberglass? Please give us your thoughts on this, as we could all benefit from a half-inch solution to a 12 inch problem. . . that did not come out right.
Below are a few cites I have used to learn a bit about the tar based products for anyone interested: Tech Talk Jay Leno uses it B-Quiet Background