703 vs. standard R-13 fiberglass?

I've got a small room (approx. 9x10x10) that I want to deaden and use as a vocal booth and as a room to master in. The idea being that a dead room would allow me to hear exactally what's comeing form the speakers. I know this is not the best method, but it's all I got right now :-) Back to the topic: There will be a false ceeling with hangers above that should take care of 150Hz and lower. I need the walls to get rid of everything else. Can I build panels out of standard R13 or do I need 703? What would the difference be? How thick do they need to be? This is the look i'm going for: And ideas on construction would be helpfull to. THANKS! :D

Greetings! I'm presuming that your goal is to bring down the room's reverb time evenly across the entire sound spectrum. The hangers in a false ceiling are a good idea, but it probably won't be enough- the high freq's will be so easily absorbed that you'll have to do a lot to soak up the lows. Either that, or put up panel traps to absorb lows yet reflect mids and highs, but I don't know if you want to do that... Back to the original question- choosing between 703 or regular blanket insulation, for me, is easy. Both! The 703 will do the most work when it's spaced off the wall. So make a 4" or so gap, and stuff the spaces behind the 703 with blankets. If you have to go only one or the other, go with the 703. But if you can do it, they work great together. Kase www.minemusic.net

I do want to get room as flat as possable. It is carpeted, so there go a lot of the highs allready :roll: Right now the room is empty and no treatment has been done yet. I'm hearing a lot around 200-400Hz. What thickness do I need to be to asorb that range? I will have a better idea of what I need once the hangers are in. As far a insulation goes...the question is because 703 is hard to come by and I happen to have a bunch of R-13 laying around. Is there anything wrong with NOT useing 703? thanks!

Chris, > This is the look i'm going for < That room indeed looks great, but I'm sure it sounds terrible. Unless some of those panels are really "false" and don't absorb, that's way too much absorption. Worse, all the absorption is at mid and high frequencies. All rooms need absorption at low frequencies too, and thin panels like that mounted flat on the walls won't cut it. In your case, with such a small room and three nearly equal dimensions, you need way more bass trapping than mid/high frequency absorption. --Ethan

I was refering to the style of the panels. I don't want to absorb wall to wall like that. Hopefully I can make those think enough to absorb low-mids also. How thick would they need to be? thanks, -Chris Parsons

Hopefully I can make those think enough to absorb low-mids also. How thick would they need to be?

It all depends on how low you want to go. The BBC designed a new absorber panel that does pretty well what I THINK you want. It is 7.25" thick and has basally flat absorption down 100 Hz with a slight dip of .98@125 Hz when mounted on 1" furring. Make yours 8" deep if you are going to flush mount. The BBC modules were made with 2.5 pcf material. Home insulation is around 2.0 pcf. If you use your current fiberglass, you will get less low end absorption. OC 703 is a 3 pcf fiberglass. This will give you better low end absorption. The make is not critical. Just ask for 3 pcf insulation panels. Another option is to use equivalent rockwool, One trade name is Roxul. A nice thing you can do with rockwool is purchase 4 pcf material and get even better low end response. I strongly recommend reading the BBC Research and Development report on the development of the absorber panel. It is located at http://www.bbc.co.uk/rd/pubs/reports/index.html Go to"List of RD Reports" and then click on the "RD 1992/11" report. It is a quite extensive description of the design process and the acoustic effects of several different things tried with the module. For example: Too much high end absorption? Look at figure 16 to see what the effect of a 20% open panel on the front the unit will do to reduce absorption at high frequencies. Enjoy! Andre

Thanks for that link, i'm very interested in reading that report. The list of reports is a PDF file with no links. I must be looking in the wrong place. Could you clairify how I get to this report? thanks for you time! -Chris Parsons

Chris, Those PDF files include active links, you can recognize them on the color, which ones are active. If it doesn't work for you, you maybe must upgrade your Adobe reader. Eric