John Sayers' Recording Studio Design Forum Archive

I was thinking about using Cork to cover the parallel survaces in my 12'x10'x8' room. I have hard wood floors and drywall walls and ceiling. I'm wondering if anyone here has experience with it and can tell me how they find it to be?

I already have bass traps in the corners but I want to reduce the flutter echo. People seem to think it's not very absorptive yet I've found that it's used as a sound absorbing material in industry underneath flooring. It's true it loses absorption if you laminate it. However, the stuff that is springy and used for billboards has different absorption traits.

It's composed mainly of tightly packed air filled cells. This structure is hard to immitate with foam. Air pockets are one of the best things for stopping sound waves.

Here's some information I found in Google newsgroups. 25mm is about 1 inch of cork. Not bad for 1 inch of material. I read somewhere that someone found 3 inch thick tiles of it. I'm wondering if you have to custom order this thickness because everywhere I looked the max thickness was around 1''.

Check out this information about Cork:
http://www.cerescork.com/whycork.html

Cork

> << I read about a product called "Quiet Cork" from Portugal that
> has an STC of 21 for just 6 mm thickness. Double that thickness and
> you should get STC 27 (6 more dB's for double the thickness). >>


> Actually the relevant data for this kind of product is going to be an
> absorbtion coefficient, not an STC rating, since for all practical purposes
> this is a surface treatment with no real sound transmission loss.
> Scott Fraser



I have some info on the absorption coefficients of 25 mm cork on solid
wall:

Freq: 125 250 500 1000 2000 4000
Coeff: 0.05 0.1 0.2 0.55 0.6 0.55


Almost like carpet but less absorptive in the highs. Someone
mentioned that cork has an odd sound and should be used with
alternating panels of wood and not as the only material.

I grew up with cork as an absorber, the first major studio I worked in in the late 0s used cork everywhere. It was 1" and 2" thick and was dark brown and every room using it had a distinctive cork smell.

Cork floors are excellent as with it's two pack bright finish it works like a timber floor except it's soft to walk on and dropped objects don't break as easily. It's also hard wearing and works well around the console area where there is heavy traffic.

cheers
john

Thanks John. So you would recommend it then? This is both a tracking and mixing room. My focus is on making a good tracking environment though. I was hoping to tame the echoes but not deaden the room.

also posted to http://www.recording.org/ftopict-24122.html

lex wrote:Thanks John. So you would recommend it then? This is both a tracking and mixing room. My focus is on making a good tracking environment though. I was hoping to tame the echoes but not deaden the room.

Taming the echos without deadening the room requires angled walls and ceilings.

I wouldn't go out of my way to get cork today as there are much better options available like rigid fibreglass.

I still recommend it for floors though

cheers
john

I think I will try your designs for slat resonators instead. I think this is exactly what I was looking for, thanks.