Cardboard isolation box

[Guitarski]

Hi everybody,

So I want to make this isolation box, but don't fancy spending a lot or doing any carpenting. Hence I was wondering: why not simply use a cardboard box? Very strong in 2 layers and in 3 layers it's air freight proof, I'd like to see you diy THAT.
The kicker of course is, will it sound allright, padded with sound isolation, naturally. Clearly, the construction isn't stiff, is that a problem, in the case of cardboard?
How to mount the speaker? I'm into no-tech solutions, so I was thinking of a frame consisting of some wooden bars that will simply keep the speaker upright, resting on sound proof foam.

It's an idiot's approach, but that doesn't mean it won't work. What do you say?

Thanks/regards
- Guitarski
www.rocking.mobi

[Guitarski]

Or does a speaker need to be fixed in position in order to displace air like it should?
At high volume I'd say it does. Then I'd need it to attach to something heavy.

Thanks/regards
- Guitarski
www.rocking.mobi

[tvrgeek]

I am not getting the goal here. Something to stick you head into? Double-wall box will be acoustically transparent below a few hundred Hz. Above some frequency, it will reflect completely. Sound is carried by the air, sorry to be obvious, so that means isolation needs to be air tight.

"Padded with sound isolation". You are talking two different things here. Barrier and absorber. Let me suggest yo go hit some of the sound control products web sites and read up from the real engineers.

I am not sure, but I think what yo are looking for are noise cancellation headphones. Experiences.

[Guitarski]

Noise cancellation, I think I have that on my MP3 player. If you listen closely, you notice some of it and with some luck it gets you dizzy (what a rush). To be honest I don't how it can significantly suppress the sound of a high gain amp.
You make it sound like I'm the inventor of the isolation box. Thanks, but I'm just trying to invent the low budget - no carpenting iso box.
I like your suggestion that I was implying that double layered cardboard will reduce volume. LOL! I like it! We should have a beer together. I'm not a real engineer, though :-(

Thanks/regards
- Guitarski
www.rocking.mobi

[PlasticIsGood]

You need mass and/or stiffness, and cardboard has little of either. However, you could use the cardboard box to define the space and enclose the mountings, and cover the box with heavy blankets when you use it.

I would guess the result will have its own sound, as the cardboard will reflect some frequencies, pass some others, resonate with several, and invent a few of its own.

Stiffness and/or mass of the speaker mounting will have an appreciable effect on the sound too.

Experiments with cardboard are cheap, and a better way of learning than asking here, probably.

Wikipedia was a good laugh: http://en.wikipedia.org/wiki/Isolation_cabinet_(guitar)

[Guitarski]

I will certainly post the results here, but I would like to conduct an informed experiment. Isolation is (sort of) cheap, but not if you buy the wrong kind. So please bear with me a little longer, before I embark on my grand experiment.
On the net I find two approaches to isolation material:
1. That sound absorbtion is in the size of the pores of the foam.
2. It's mass that matters. Then any foam would consist of flakes rather than a uniform distribution of pores. Other materials than plastic foam are possible as long as it's heavy.

Does any of this ring a bell with anyone? I will certainly contact the shops that sell it for the same question.

Thanks/regards
- Guitarski
www.rocking.mobi

[picowallspeaker]

Go to some automotive parts shop, better a body shop
and get some of two layers made of tar foil + low quality felt (waste )
or just tar foils ( about 2-3 mm thick).
Those would form the constrained layer damping formed together with
the ( thick and dimensionally built to sustain the forces that happen in a box)
cardboard and the fancy cover ( I used PCV foils).
The knock test would give you the measure of it all

[Guitarski]

That's excellent info, many thanks.
So you pioneered the cardboard part? How did you mount the speaker? I realized it needs a stable, rigid platform, so I reckon I will need to use a regular 1x12 cabinet anyway.

Thanks/regards
- Guitarski
www.rocking.mobi