I use the border (or rim) approach as well. I use it when the
unwanted sound is to the side of the dish. Usually top center where I
can match time of arrival (jets are the exception).
The approach I demonstrated (mics next to) works best when the
unwanted sound is in front of the target or behind the dish.
And why is this approach important in the world of computer noise
reduction? Because, instead of working with "specific source" noise
reduction in terms of 4 to 10 db before artifacts comming into play, a
specific noise source can be reduced by the level that your mics are
matched. Under really good situations looking at a specific noise
source and recording in 24 bit I can reduce that source by all of the
16 bit end product or 96 db. If I have time, like a slow porcupine
and am careful.
Ok I like that, lets give the "dead" the credit as that makes it
clearly patent free.
Rich Peet
--- In Gianni Pavan <> wrote:
>
> Hi all, there are two more examples worth of consideration and
experimenting:
>
> - to record very weak sounds from insects it is often required to
> place the mic as close as possible, but still a lot of noise come
> from the surroundings. a technique is to use two identical mics, one
> close to the insect and the second at a short distance. then by
> subtracting the far channel from the close channel you suppress most
> of the general noise and keep clean the sounds captured by the close mic
>
> - while using a parabola with a mono mic in the focus, you can also
> place an identical mic on the border of the dish and then subtract
> the border sound from the focus sound.
>
> Gianni
|