Thanks for trying that, John. I assume it might give more consistent result=
s to position one microphone at the focal point and ignore the other?=0D
=0D
Peter Shute=0D
=0D
=0D
--------------------------=0D
Sent using BlackBerry=0D
=0D
________________________________=0D
From: =0D
To: =0D
Sent: Sat Jan 07 10:34:48 2012=0D
Subject: Re: [Nature Recordists] Fuzzy Blobs=0D
=0D
=0D
=0D
Getting back to those interested:=0D
I tested a Sony PCM-M10 mounted a Telinga parabolic dish (the M10 mounted a=
s shown in the photos below)at 20 feet and 70 feet using a small speaker pl=
aying radio static noise and by shaking dried beans in a paper bag (David's=
"peanut" test) while moving across the direction of focus.=0D
This resulted in a audible split focus with a hole in the center. A slight =
change in direction of the parabolic dish a few degrees to either side from=
center relative to a fixed subject shifted the amplified focus to one caps=
ule or the other. When played back in stereo on speakers a drop in the cent=
er was quite apparent. However, when mixed to mono the center seemed to sum=
(?) in a way providing sufficient lift between the dual focuses so any dro=
p from crossing the center was no longer apparent. While the amplification =
at these, slightly off parabolic focus, dual focuses is certainly less than=
what could be expected at the true parabolic focus, it seems there still s=
ufficient gain (maybe 6 to 8 dB) to still consider the arrangement a highly=
directional microphone.=0D
=0D
This photo should give an idea how the M10 was mounted.=0D
http://rockscallop.org/test/20120103_m10-mount.jpg=0D
=0D
Here is a photo of the whole setup on tripod stand.=0D
http://rockscallop.org/test/20120103_dish-stand.jpg=0D
=0D
John Hartog=0D
rockscallop.org=0D
=0D
=0D
=0D
|
