Some help on this soundproofing project

R

rockabilly

New member
Alright! So I am getting together materials to build a guitar amp isolation box to fit my little, but big sounding, Fender Pro Junior.

I am going to be modifying a design that this guy used. I may even make a box inside a box. And this thing is gonna be as air tight as possible.
http://www.amptone.com/diyisobox.htm

However, I know that foam does little to nothing to stop sound. I have been reading around here and everyone gets confused between sound proof and acoustics.

So, I am trying to figure out what SOUNDPROOFING material I should put on the walls of the inside of the box. Whatever I put, I will probably also put 703 rigid fiberglass over so that itll absorbe some bass from going back into the mic thats recording the amp.


Im guessing 703 rigid fiberglass does nothing to stop sound from going through. I think ive read something about wool??? Ive read about some of that soundstopping vinyl...but yeah, i dont need a whole freakin mega roll and i havent seen anywhere online i can buy it by the square foot.

Any suggestions for that SOUNDPROOF material?
 
Edit: I jsut read that you mention the box within a box, forgive me for not noticing when i wrote this goddamn book.

That design looks great, but i have a bunch of suggestions, having built an iso box myself recently and have plenty of thoughts of how i would do it better.

1. Soundproofing = decoupled mass. That design won't do it in my opinion, because the sound (LF especially) will go right through any absorbtion material and the walls of the box will turn into wooden speakers (I say this from experience). When i built my box big enough for my amp (blues deluxe, about 2 feet wide by a foot deep by a foot and half tall) it killed the highs fairly well but the bass went through the whole house anyway.

2. But build it anyway! Line with 703 or whatever, i woudl try to do 4 inches, but you might not have space. Then build a second box to house the speaker(s). This sounds like a pain, but it is a great idea. If you either buy some extra speakers and uset them for your box, or (as i did because i didn't have the $$ to buy new speakers) take the speaker out of the cab or combo amp, you can mount it in the smaller box, add some treatment in there and room for mic(s) and close that box up tight (add a trunk locking clasp to tighen it down nicely) and then put it inside your bigger box and shazam! you will have much better islolation. You will probaably still be bale to hear a cranked amp in the room, I can't imagine true isolation without some serious construction, but this is as good as it will get.

Note that since you will probabaly only be micing one speaker at a time, you only need to put one speaker in this box. Now, i have a mic cable and a speaker cable coming out of both boxes and running to my amp and pre's, which are conviently located outside the box, so as i am monitoring the recording i can tweak knobs and such. If you put the whole amp in the box it is a HUGE pain in the ass to open it all up and tweak something, close it back up and test it, then tweak again, etc.

3. If you go with that design, you can do some really cool things. In mine, I have mounted the speaker on a piece of high qulaity plywood, i have rigged mounting slots of sorts insider the interior box that i can slide the plywood into and I picked up a second speaker and now i can switch them out for different tones.

4. Build it so you can open the door from the front or side rather than the top. A big box makes a great table and it will quickly gather all sorts of crap on top and if you need to move all that shit every time you need to get into your box you will blow a gasket. I made this mistake myself and kick myslef all the time for not thinking it through first.

5. Leave plenty of room for the mic(s). I like to use an EV RE27 from time to time, and it is a big damn mic and space gets tight inside the box. The box also gives you a nice space to put multiple mics to A/B for the best tone, and if you screw yourself on space you won't be able to fit more than one in there.

6. Caulk the joints inthe boxes, and put clasps on the boxes to tightenthem down nicely, to improve the isolation.

7. My best opinin on your question is that 703 will be fine to provide SOME absorbtion, but nothing that doesn't involve lots of truly decoupled mass will truly soundproof, thus the box within a box. if you could put the interior box on something like a few nails from the bottom (so it is connected only by the points of hte nails or other something like that) it would probable help avoid sound transference through materials as one box rests on the botom of the other, but i find that it works pretty well with something like 703 between them.

That is all i can think if right now, hope it is helpful, good luck.

Daav
 
rockabilly1955.....yeah used to be Rockabilly Monthly.


daav! your my boy! Awesome suggestions. Wouldnt it be awesome if I could just find a coffin? Those things are air tight and NO sound gets through those! It would truly "Deaden" the sound....get it?

Cant wait to start building away.
 
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