Ok I know newbie question. What is this rigid fiberglass all about. I have heard alot about it but what exactly is it. I know they are for sound absorbing panels but I work alot around boats doing fiberglass work but there is no way fiberglass would absorb any thing after the resin and everything goes on. I have looked up some of the websites but cant really find a answer.
whats this rigid fiberglass all about???
- Thread starter stoctony
- Start date
how do they keep it compressed. also is the # the R value for it or what.??
As far south as you can get. I tell everyone South Padre Island because that where I work. But your from texas so I will tell you I actually live in brownsville.....I know, you dont have to cry for me..
As far south as you can get. I tell everyone South Padre Island because that where I work. But your from texas so I will tell you I actually live in brownsville.....I know, you dont have to cry for me..
pdlstl
New member
stoctony said:
I don't know how they keep it compressed. Maybe someone else will chime in.
The "number" is the NRC value. 1 = 100% absorption.
From the Johns Manville FAQ's:
An NRC (Noise Reduction Coefficient) is a single number rating that is used to describe how well a material absorbs sound. A material with an NRC of 0.70 would absorb approximately 70% of the sound and reflect the remaining 30%. The NRC value is measured according to ASTM test method C 423 "Standard Test Method for Sound Absorption and Sound Absorption Coefficients by the Reverberation Room Method" by measuring the reduction in reverberation time with the use of the material. This test applies only to materials that are exposed to the sound source as installed. Because fiber glass batts are typically installed within a wall cavity, the NRC rating would not apply. Generally speaking, unfaced fiber glass batt thickness' greater than 2 inches would have an NRC of 1
Brownsville is cool. We have an office there.
Earl
Michael Jones
New member
stcotony - it could be worse, you could be from McAllen!
(I went to 2 years of H.S. there)
(I went to 2 years of H.S. there)
Nope gotta say brownville is worse. Anyway, I was in the A/C business for awhile and this stuff sounds like the "glass board" that we would use to make custom duct work. I was yellow and has a foil backing. It was only like 12$ for a 4X8 sheet. Also it sounds like you could use normal batting like up in you attic if you were to put a backing on it. Does that sound like it could make sense to you guys. If the 2" batting absorbes 100% of sound is that what you want?
Also. Earl check your PM's
Also. Earl check your PM's
Like I explained before, I am doing solo acoustic. recording and listining room. I would like to have a room for just vocals but I will have to see what this one would sound like. i have 15X20 room. Gutted and wondering what to do with it. (acousticly) Tile floors though. what do I do with that.
RICK FITZPATRICK
New member
Creating an air gap between the 703 and a wall does not "trap" anything. The reason people do it, is to increase the distance from the face of the 703 and the wall, as the reasoning is this. 703 absorbs because it is a fiber material which has close nit "intersticies", which creates a RESISTANCE to the movement of air molecules. It is this resistance that converts the sound wave energy to heat, hence absorption. Since the velocity of the wave is greatest at 1/4 wavelength, the distance from the face of the absorber to the wall, determines the lowest frequency which will be absorbed. Since velocity is zero at a wall, there is no need for the absorber to be against the wall. Spacing it 1/2" to an 1" is recommended here often. A 100 hz sound has a wavelength of 11.3 feet. Therefore, 1/4 wavelength equals about 2.825 feet, which explains why resistance absorbers absorption drops off dramatically. If you only have 4", with 1" airgap, figure it out. What 1/4 wavelength equals 4.5". The the real eyeopener is doing the math. This will tell you the truth, instead of guessing. The equation is:the speed of sound
1130 feet per second(close enough)
divided by the frequency equals the wavelength.
Divide that by 4 and it will tell you the 1/4 wavelength.
But then, how do you know how MUCH you are absorbing in SABINES? How much absorption do you need? 1 square foot of open window equals 1 sabine.
fitZ
1130 feet per second(close enough)
divided by the frequency equals the wavelength.
Divide that by 4 and it will tell you the 1/4 wavelength.
But then, how do you know how MUCH you are absorbing in SABINES? How much absorption do you need? 1 square foot of open window equals 1 sabine.
fitZ
UhHHHhhhHhh. Thanks. Just kidding I understand. Math the universal language. this is how the spacing determines the freq absorbed. How can I tell which freq I need to absorb with the room setup that I have? Do I just get as many as possible and put them everywhere? What are the rules as to where I need to put them and how many.
Thanks is advance
Stockton
Thanks is advance
Stockton
Michael Jones
New member
You just missed it.stoctony said:
We covered that about a week ago.
Plenty of info on it here:
https://homerecording.com/bbs/showthread.php?t=120151
pdlstl
New member
RICK FITZPATRICK said:
Wow Rick! Great information! Thanks!
I went back and looked at some of your other posts and am quite impressed. Obviously you've done your homework.
I'd love to see some pics of your studio if you wouldn't mind posting them. Perhaps I can "steal" some good ideas from your set-up.
Also, if possible do you have anyplace where I could hear some of what you're recording?Cheers,
Earl
RICK FITZPATRICK
New member
Hello Earl, thanks for the vote of confidence. I've delved into the design, construction, and acoustical areas of studio ideals for quite a time, but have never been in a position to utilize most of it. I do have my own "recording and listening" room, but have not finished it at this point. Time and money dictates the rate to which goals are attained. Ha! Which in my case is at a snails pace. My room is actually a nice quiet upstairs room, with my console facing a sliding glass door with a view of Oregon nature, and my house sits at the top of a hill isolated from most noise, except the occasional train and or log ship. I have yet to do any recording here, as the room is not finished, although that wouldn't stop me if the inspiration hits. It's haveing the equipment hooked up, which at this point ISN"T. 
Soon though. My studio is mostly analog(2 MSR-16's synched via a Midiizer) but I also have a Lexicon Core 32 digital system with most of the current software. But I love the analog sound.
I do have a plan though. Mostly, this is designed to make me happy with my rooms enviornment, not to satisfy acoustical perfection. I'll never get there, so gotta get happy with what I have at this point. Anyway, here is my plan.
fitZ
My room is actually a nice quiet upstairs room, with my console facing a sliding glass door with a view of Oregon nature, and my house sits at the top of a hill isolated from most noise, except the occasional train and or log ship. I have yet to do any recording here, as the room is not finished, although that wouldn't stop me if the inspiration hits. It's haveing the equipment hooked up, which at this point ISN"T. Soon though. My studio is mostly analog(2 MSR-16's synched via a Midiizer) but I also have a Lexicon Core 32 digital system with most of the current software. But I love the analog sound.I do have a plan though. Mostly, this is designed to make me happy with my rooms enviornment, not to satisfy acoustical perfection. I'll never get there, so gotta get happy with what I have at this point. Anyway, here is my plan.
fitZ
