Beaulieu 4008 Barney

Post by **paulcotto** » Thu May 29, 2003 3:04 am

Do I understand you correctly? The acoustic material makes the PVC conduct sound more readily?

Regards,
Paul Cotto

mattias wrote:
paulcotto wrote:What about a piece of PVC pipe
might be a good idea, but if we're to take the dead material thought into account i don't think it is anymore. pvc pipes are more acoustic than trumpets. ;-)

/matt

Post by **Lucas Lightfeat** » Thu May 29, 2003 3:30 am

No, I think Matt's saying that PVC is not a very good sound insulator, as it vibrates too freely.

I personally don't think it's such an issue with the noise levels we're talking about, however. If it were lined in thick felt, it would work fine. Infact, it's a great idea!

Lucas

Post by **paulcotto** » Thu May 29, 2003 3:35 am

Thanks, I try to think outside the box

I think about 50% of my ideas could work but they might inspire the next great idea, who knows.

Regards,
Paul Cotto

Lucas Lightfeat wrote:No, I think Matt's saying that PVC is not a very good sound insulator, as it vibrates too freely.

I personally don't think it's such an issue with the noise levels we're talking about, however. If it were lined in thick felt, it would work fine. Infact, it's a great idea!

Lucas

Post by **Scotness** » Thu May 29, 2003 1:35 pm

I don't think it's actually that hard to work out the wavelenght - correct me if I'm wrong though -- but I tried to work it out for my Beaulieu 4008 once - and I think it was one to two metres -- I can't remember the specifics but here's how I did it:

velocity = frequency x wavelength

wavelength = velocity divided by frequency

Velocity is the speed of sound which varies with atmospheric pressure/temeperature etc - so I just grabbed some standard quote for it

then got a sample of the camera sound and did a frequency analysis with it in Cool Edit (and took the fundamental not any harmonics)

and then worked it out from there

I don't have any samples or Cool Edit on this computer but maybe someone could try it and put their results down

Come to think of it the wavelenth might have been closer to 4 metres and hence the foam would be one metre - can't remember

Happy calculating!

Scot

Post by **calgodot** » Thu May 29, 2003 5:17 pm

Paul Cotto, thanks for the suggestion. The molding & casting itself is no issue: my friend is a makeup effects pro and has a fully equipped shop. Additionally, I've got about $1000 sunk into my camera, and am in no way inclined to experiment with it! I'm already going to have to take about 6 Valium when we wrap it in plastic and pour silicon all over it!

Lucas, we're probably going to try a plastic resin first. It's expensive, yeah, but so are my tastes. ;) My friend has worked with it before: I'm pretty sure it was his first suggestion. Thanks for the tip about lining it with felt: I was going to try an acoustic foam spray inside just to add extra insulation. I can put the felt on top of that and... oooh, geek moment! (Now who's laughing?)

I dig your idea about a rotating blimp for the lens. I was reaching the point where I was just going to blimp the body and make a simple barney for the lens. Your idea Lucas would allow me to make a separate mold for the lens that most people have on their 4008 (with that huge ugly heavy clunky auto shit all around it), should I decide to offer or sell this to others. (I won't make that decision until I have it working.) I may have to walk over to Birns & Sawyer today to look at an Arri 16BL.

Also, is it insane that I want to hand-hold my blimped camera?