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1. Re: Decca Tree?

Subject: 1. Re: Decca Tree?
From: "Dan Dugan" dandugan_1999
Date: Mon Sep 8, 2008 10:12 am ((PDT))
re the cardioid response,

>  As we move
> around to the 180 degree point, the sounds captured by the rear of
> the bidirectional are reverse polarity to the sounds captured by the
> omni, and therefore cancel each other out, resulting in 6dB less
> level than at 90 degrees and therefore 12dB less level than at 0
> degrees. And these are the characteristics of a true cardioid
> response: 0dB on axis (0 degrees), -6dB at 90 degrees, and -12dB at
> 180 degrees. (Thus, the rear rejection of a true cardioid is only
> ever -12dB.

John Lundsten's correction is acknowledged. To amplify:

Adding two identical signals in phase increases the level by 6 dB. But
subtracting two identical signals nulls!

-Dan Dugan







"While a picture is worth a thousand words, a
sound is worth a thousand pictures." R. Murray Schafer via Bernie Krause


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