John Sayers' Recording Studio Design Forum Archive

I'm a student of the SAE in rotterdam (NL) and I have to design my on studio. All is going pretty good, but I'm now at the point to calculate the transmission loss.

Althought this isn't the problem, I don't know how a calculate this over multiple goods at the same time. (concrete, rockwool, wood)
Do I have to calculate them seperatly and them count them to gether,
and if so how do you do this.
You can count dB like normal numbers.

Or do any of you use another calculation.

I'll give you my walls:

1 cm wood board for looks
5 cm wooden frame (in between the frame rockwool will be inserted)
9 cm concrete wall
10 cm air (vacuum)
9 cm concrete wall
5 cm wooden frame (in between the frame rockwool will be inserted)
1 cm wood board for looks

Thank you for any help,

Alex

Alex, the best thing you can do is join this forum

http://forum.studiotips.com/index.php

And talk to Eric - the simple demo program I use a lot is no longer available online, and the new version RANDOMIZES everything so it's USELESS for any real calculations. The full program (Insul) costs around $1000.

Eric's spreadsheets are free to members -

http://forum.studiotips.com/viewtopic.php?t=1414

HTH... Steve