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Re: Idea's for recording kit

Subject: Re: Idea's for recording kit
From: "Rich Peet" richpeet
Date: Wed Aug 16, 2006 9:53 pm (PDT)
I think there is only good caffeine, so I will go with that.

The way I visualize a parabolic is by focused globes of sound.
The highest pitch sound you can possibly hear will perform similar to
light from the sun and its focused pattern in front of your dish. If
that focused pattern is not larger than the size of your mic capsule
you should not have a loss with the amount of physical distortion your
dish is undergoing at any audio frequency. In other words an audio
parabolic does not have to be a good as the stuff used in camera and
telescope work.  With sound the size of the amplified focused globe
does change in size with frequency.  When the physical size of a low
pitch audio wavelength exceeds the size of your parabolic then don't
expect much of any amplification. 

The question I raise is if sound acts the same in free space when it
sees a barrier as it does in the amplified reflection within a
parabolic.  In my eyes putting a barrier next to the mic within a
parabolic dish makes the capsule only see 1/2 of the dish.  We will
see, I will try and play with this with different size barriers and
pink noise.

Rich Peet
Everyone here comfy with not having your electronics as carry on?  And
if no one has authority to tell you that you are considered a
subversive, then who has authority to confirm you are not?  Be sure to
hit your new passports with a good EMP.

--- In  "John Hartog"
<> wrote:
>
> It will be interesting to know what you find with your tests, Rich.
> 
> I'm wondering if the "no noticeable decrease in gain with a barrier" 
> effect is particular to less-rigid dish materials.  Because the dish 
> warps under its own weight a bit the focus also becomes somewhat 
> warped or stretched, thus the gain at any specific point is already 
> compromised.  A barrier might make up for this a bit by obstructing 
> the diffusion or by offering a pressure zone.  
> Based on this conjecture, would you say I'm on -  A:) good caffeine, 
> or B:( Bad caffeine?
> 
> -John Hartog
> 








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