Cardboard boxes

[kikk]

Here is the thing.
My father just built a new room made out of concrete.
He also owns a store so he has a lot of cardboard boxes which he also stack full of cut up cardboard to burn them later on.

The thing was that he stacked up a whole corner with boxes and it was insane how much it absorbed the sound of the room.
I don`t have a chance to do measurements at the time.

But what frequencies do these boxes absorb?
The thought striked me that it could maybe be usefull in studio applications.
Probably not but what effect would they have?
What gas flow resistivity do cardboard have?
They are something like 8x8x10 inches and stacked with layers of cardboard.

If nothing they would be a good frame for insulation bass traps right?

[John White]

Originally Posted by kikk

The thought striked me that it could maybe be usefull in studio applications.

Sure! As a very inexpensive alternative to "proper" treatment, they can be filled with loose batts of insulation and then stacked randomly. This would benefit you with absorption and scattering. Perhaps try this in the back of your room. I'd be interested to see your results as well as your interpretation of randomly stacked.

[kikk]

Thank you John.
Any idea what frequencies cardboard boxes stacked with cardboard will absorb?
I`m just curious about it.
I wont use them as bass traps or something like that.

Did you work out the rew issues?
I had luck with using soundflower.

[DanDan]

I have used cardboard boxes for LF trapping. I filled them with bunched up newspapers. I'm sure insulation would be better. Seemed to work well audibly, never tested it though.
Must try SoundFlower.
DD

[John White]

No, Kikk. No luck yet. It seems to have something to do with the amplitude. It doesn't seem to recognize signals unless extremely loud. Same goes for other recording software. I think it's in the computer itself, though I don't know how to find out. Sucks. I downloaded Soundflower, but I don't even know what it is.

My guess with what cardboard boxes would REFLECT the high frequencies just fine if only in relation to what I've seen with absorption coefficients on this page: http://www.bobgolds.com/AbsorptionCoefficients.htm

If you look at the absorption coefficients of say OC 703 with FSK, you'll see a steady drop off of absorption in the high frequencies. (This may seem basic to you, but it's the only analogy I can think of.) In addition, bass absorption INCREASES with the FSK. Win win! I like it because it seems to be somewhat of a steady drop off within the STC range. Probably not quite as steady as we look for in the music range, but not bad for free boxes.

Difficult to say if the box cardboard will be much more reflective than the FSK, but probably a bit anyway. Fill those suckers up with attic insulation and you potentially have the making of cheap and decent absorption.

(I did notice the box sizes were really small. This may be an awful lot of work to fill all those boxes stacked high in the back of your room. The theory is cool, however.)

I wouldn't use them as absorption unfilled as my guess is it would probably take too many to make the space lost to a bunch of cardboard boxes worthwhile. I still like the idea, if only the idea, of stacking the filled boxes in a random order in the back of the room to give yourself absorption and a degree of scattering. You know, like some on angle, some straight on, etc.

[DanDan]

email me at the address on my website John and I will try to get you going on REW. The onboard I/O is the way to go.

DD

[John White]

Originally Posted by DanDan

The onboard I/O is the way to go.

Thanks Dan, I will in the next few days.

Just for the record for other readers, I have had good success with BOTH onboard I/O and USB-DAT so as not to discourage other Mac users. Stupid computers.