[Lemonsqueezer]

Originally Posted by SkiBum

I'm not a professional acoustician, but I have studied the subject enough to know there is some missing data in this long thread. I have a couple comments:

First, about the traps mentioned in the original thread, these are not bass traps. They are full range absorbers. If you use 6" of 703 you have a full range absorber, like an open window - all sound goes in and does not come out. To absorb bass only, you have to either use a membrane design or a Helmholz resonator.

You should be able to get bass absorbtion by putting them in your corners at 45degrees to the walls, where the bass builds up.

Another post said that you can leave plastic wrapped around the 703 and they work almost as well. Sorry, but that's illogical if you know how they work. The air pressure waves go into the material and are absorbed. If the waves can't get into the inside of the material they are not going to have any significant effect at all.

I would recommend studying more about the subject before building traps or you won't get the great results you are after for your hard work and money. Dalton Everest's books are excellent.

I made traps - 3 kinds: low mid and full range - based on his designs and with his calculations, and they worked beautifully in my old studio.

Also, hemp may have a sound absorbtion rating that is decent (although I doubt it), but I would want to actually know before I used it in my studio, although I applaud you for finding a healthier material than fiberglass (cotton batting works pretty well). I just hope it is really working for you. Considering how much you put up it might do OK on some frequencies. You can probably find an acoustic rating for it somewhere. Maybe the manufacturer can help with that.

I'm not trying to be a know it all or rain on anybody's parade. Acoustics is a fun subject. Understanding the science, it can be even more useful.

Would love some more info on your traps. Sounds interesting. Some pics would be cool as well.