complicating bass traps

[doulos]

ok so I'm extremely broke right now and more importantly have limited time. I have a untreated room. I want to revamp the whole room and get some acoustic treatment in place. I can only get rigid fibrglass if i pay 30 bucks in shipping on every 6 panels and to me thats to much on my budget so here goes

the room is 13 1/2 long by 11 1/2 wide I have 2 doors on the right side of the room. main door and closet on the far front and back walls. Dead center on the left side of the room I have a window 39 wide by 35 high and I have a celing fan in the center of the room. I don't know how to measure the room. do I remove everything? do I leave the mix position alone? not sure how to do it

I have a db meter roomeq wizard and a rode nt5 microphone I can use

ok now on to the bass trap looking at the Absorption Coefficients it gets confusing 6 inch 703 is 1.19 at 125hz and Unfaced 12" r-19 pink fiberglass on the wall is 1.14 at 125hz here is where im getting confused

what size is the r-19 thats measured or does it matter?
another question can I compress the r19 from 12 inches to 6 or even 4 without ruining the acoustic properties of the material? and 2 more and ill be done

does it have to be r19 or can i use r30? will faced or unfaced matter?

and the main question If I build a 12 inch thick r-19 fiberglass panel compressed down to 6 or 4 inch wood frame 2 foot wide by 4 foot long will it work similar to a 6 inch 703 panel for a bass trap?

[CIRO]

Originally Posted by doulos

and the main question If I build a 12 inch thick r-19 fiberglass panel compressed down to 6 or 4 inch wood frame 2 foot wide by 4 foot long will it work similar to a 6 inch 703 panel for a bass trap?

Take a look ( post nº 5)
http://www.gearslutz.com/board/bass-...roperties.html

Ciro

[doulos]

My conclusions:
- More is not always better.
- It always depends (i. e. on the frequency range, the absorber width and position, the gap width)

Somebody who does not know what he/she is really doing may end up spending much money with mediocre results. Cruel but true :-)

Hope this helps

no i already knew that and it doesnt answer my question to well lol

I know i can screw something up im trying to AVOID That by asking questions

[oblackmer]

First thing, are you sure you cant find any RFB anywhere else? Did you get your quote from a local HVAC supply company because that is where I have always gotten it. It is expensive, but worth it.

You may be able to squeeze a decent amount of resistance into loose fiberglass by putting it under pressure. Ideally you still want to have RFB over the surface but when we build absorption we usually start by building a very stiff wood frame 6'' to 12'' from the wall and compressing loose fiberglass between cut lengths of Armstrong ceiling tiles; the ceiling tiles are angled towards the sound source in order to diffuse sound back into the FG

The advantage to this is that if you do it right you can stretch a light cloth over the frame (usually with RFB behind it) and it ends up looking almost professional. For a small home studio this may be just the thing. And it may be within your budget.

I dont really know how to explain the process in a way that will be easy to replicate, I build these things all the time with Blackmer Sound but its hard to describe without visual aid. Are you willing to download Google Sketch-Up? its a REALLY simple design program that is FREE.

ALSO if you happen to be somewhere where you can easily buy batts of recycled cotton insulation, the cellular nature of the strands is much better for absorption than fiberglass. and it sucks WAY less.

[Supercreep]

Try to find mineral wool or rock wool instead. Find out if there's an SPI around: http://www.spi-co.com/

I'd say something in the 3.5 - 6 pcf range.

I'd use the Superchunk method if I were in your shoes: http://forum.studiotips.com/viewtopic.php?t=535

[doulos]

"Try to find mineral wool or rock wool instead. Find out if there's an SPI around: http://www.spi-co.com"

I can only get rigid fibrglass if i pay 30 bucks in shipping for every 70 I spend on fiberglass and to me thats to much on my budget i live near huntsville alabama so im 90% sure i cant get the materials locally

First thing, are you sure you cant find any RFB anywhere else? Did you get your quote from a local HVAC supply company because that is where I have always gotten it. It is expensive, but worth it.

oh yes i can order it if i order a case of 12 pannels for 180 dollars with a 10 cause minimum order so if i had an extra 1,800 dollars lying around they could help me out but i dont and wont in the near future

[doulos]

You may be able to squeeze a decent amount of resistance into loose fiberglass by putting it under pressure. Ideally you still want to have RFB over the surface but when we build absorption we usually start by building a very stiff wood frame 6'' to 12'' from the wall and compressing loose fiberglass between cut lengths of Armstrong ceiling tiles; the ceiling tiles are angled towards the sound source in order to diffuse sound back into the FG

my room is 13.5 by 11.5 diffusion is the very least of my worries

ALSO if you happen to be somewhere where you can easily buy batts of recycled cotton insulation, the cellular nature of the strands is much better for absorption than fiberglass. and it sucks WAY less.

the only thing i can get is this

http://www.homedepot.com/webapp/wcs/...3+90089+531841

or this which is paper based

http://www.homedepot.com/webapp/wcs/...3+90089+531844

and here are my issues with it what is there absorbtion coefficient per thickness?

what would i need to reach the magical 1.0 for 125hz?

[Supercreep]

Originally Posted by doulos

"Try to find mineral wool or rock wool instead. Find out if there's an SPI around: http://www.spi-co.com"

I can only get rigid fibrglass if i pay 30 bucks in shipping for every 70 I spend on fiberglass and to me thats to much on my budget i live near huntsville alabama so im 90% sure i cant get the materials locally

First thing, are you sure you cant find any RFB anywhere else? Did you get your quote from a local HVAC supply company because that is where I have always gotten it. It is expensive, but worth it.

oh yes i can order it if i order a case of 12 pannels for 180 dollars with a 10 cause minimum order so if i had an extra 1,800 dollars lying around they could help me out but i dont and wont in the near future

Mineral wool /= rigid fiberglass. Kthanxbye

/looks at your signature meaningfully/

[Jeff_D]

Rock wool is used in everyday commercial construction as soundbatts or firebatts. I guarantee someone around you (or the closest city of any size) has a shit ton of this stuff. It is not hard to find, but you wont find it at Home Depot or Lowes, so don't even bother.

You're not looking hard enough... Find it, and you wont be disappointed.