[Elecraft] Elecraft Digest, Vol 129, Issue 33

[CR]

On  25 Jan 2015 at 09:48 Jim Brown wrote:
> There are (at least) three reasons why an array of microphones is a
> really bad idea. First, really good sounding mics to work with our
> radios are widely available cheap. Second, a microphone is an
> electroacoustic device -- it collects sound at a point in space and
> converts it to voltage. A microphone at a different point in space
> collects different sound -- there is a difference in time

We've a more familiar radio analog; think of collinear antennas. If the 
difference in path length between any two  and the source is 1/2 
wavelength (*sound* travels 1100m/sec at sea level pressure) that pair 
will have a null at frequencies whose phase on arrival differs by 180 
degrees.   And that's only one thing we watch out for.

Interesting discussion, if a bit OT.

Cortland Richmond KA5S
KX3 1475