How much roxul in basstraps

Hi :D Hi I'm building 4'X7'X1' basstrap that will be against the rear wall of a creation room. I have 3 inches thick roxul mineral fibre. I have room (12 inches deep) to put one 3/16' massonite pannel roughly smaller than 4'X7', and staple each side of it of roxul plus another layer on the back wall for a total of +- 9 inches of mineral fibre. My question is: by adding this mass to the massonite (total of 6 inches thick) will affect the resonnance of the trapping. Is it good or bad? Should I put about half of thickness on each side of the massonite so it mooves moore freely or I can just apply the whole thickness? Thanks in advance. :wink: Nota: in inches the basstrap is 48 inches high by 83 inches wide by 12 inches deep.

I'm not sure what you mean exactly, any change of posting a drawing of your plans?

No I would say that it is a frame built of wood that is opened at the front and covered with fabric. Inside of this "box" is a massonite suspended under the top "shelve". This resonnator (thin massonite) is covered each side of roxul and at the back on the studio wall (gyproc)there is roxul too. The massonite is suspended about halfway of the deph (12 inches) so this resonnator is suspended about 5 inches from the front. I don't have a software to make a good presentation... I hope you understand with the new details :oops:

this link shows many types of room absorbers including rear room absorbers. http://www.johnlsayers.com/HR/index1.htm

I don't have a software to make a good presentation...

Try "SketchUp". Download it from Google. It's free! Everyone here uses it. - Stuart -

I don't have the time for now to study for good results but I've tried it anyway. This is a rear wall type basstrap that there is on the link you gave me (thanks petrovinski) except the way it works. Here is the link for the draw http://www.freeimagehosting.net/uploads/th.495b910022.jpg

Let me guide you to the stickies then first, please fill in your profile. Update your knowledge by reading this forum. I'll dig into your question as soon as I understand what you mean ;) As I understand you want to build bass-trap HANGERS. But I still dunno exactly what your question is, might be the language barriere here.. sorry.

Done for the profile :)

Ro wrote:

I'll dig into your question as soon as I understand what you mean ;) As I understand you want to build bass-trap HANGERS. But I still dunno exactly what your question is, might be the language barriere here.. sorry.

Yes bass-trap hangers! The suspended sheet of massonite (3/16" thick) is covered both sides of 3 1/8" of Roxul (mineral fiber) for a total of 6 1/4" of Roxul. This is a bit of a mass added to the hanger. Is it too much of Roxul? :) Thanks for your patience :wink:

Don't worry about the mass. Wool ain't THAT heavy. It's there to absorb. Hangers are fuzzy things. Haven't really been tested. Am I a hanger-kinda-guy? neh, too much work and too much unknown variables. I'd stick with wool filled cavities. BUT, I'm just an overnight expert and am sure John (the owner of this site) can tell you much more about those beautifull devices. Yes, he builds them. ..

I tell you that this hanger must weight at least 40 pounds because mineral wool is much heavier than fibreglass wool :shock: I Know that they are hard to predict but I've always been impressed(that's my second studio with hangers) with the results and combined with standard type broadband bass-traps. Thanks for your help!

check this thread freemidnight viewtopic.php?f=2&t=12365