naturerecordists
[Top] [All Lists]

Re: Cardiod v's omni in a reflector

Subject: Re: Cardiod v's omni in a reflector
From: "Walter Knapp" waltknapp
Date: Fri Jul 20, 2007 7:55 am ((PDT))
Posted by: "no_mas_films"

> Paul, thank you very much for posting this file! Although the book is 
> long out of print, I think his conclusions are valid and will hold 
> sway in my choice of microphones for the parabolic I am currently 
> building. So far, I have purchased a used AT4041 from eBay and this 
> passage reinforces it's use. Thanks again, and could you scan and 
> post the rest of this book?  :-)    Chris

Parabolas back then tended to have longer focal lengths relative to dish 
depth. This placed the mic out in the interference pattern in front of 
the dish as described. A cardioid would not fully compensate for this. 
Also, placed out that far it's wide pickup would include sound direct 
from the side that was not part of the reflected sound. The real answer 
was to go to dishes that were deeper relative to the focal length, thus 
placing the mic within the dish. This is a better and more direct method 
of compensating for the interference patterns. And more or less removes 
this "advantage" of a cardioid. Most modern parabolic dishes are deeper.

To my mind the even better way to go is to set up the parabola as stereo.

Walt




<Prev in Thread] Current Thread [Next in Thread>
Admin

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the naturerecordists mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU