I've scanned the relevant 5 pages of the Reflectors chapter from John
B. Fishers "Wildlife Sound Recording" and uploaded to the files area.
Given the book is long out of print and the extract is small I'm
assuming it's ok to post this. If not please let me know and I'll
remove the file.
cheers
Paul
On 18/07/2007, at 9:36 PM, Paul Jacobson wrote:
> I'm not a dish user so I can't verify the veracity of this in
> practice, but I was reading John Fisher's "Wildlife Sound Recording"
> the other night and came across an interesting tidbit relating to
> cardioid and omni's in parabolic dishes.
>
> In Chapter 5 - Reflectors - Fisher discusses at length tests carried
> out by Professor G. N. Patchett of various 24" reflectors which
> showed a -7dB dip in gain between 600-700Hz. This was attributed to
> "... partial cancelation of the reflected wave by the direct sound
> waves." Several pages later Fisher states "As the cardioid has very
> little response from sound waves approaching from the rear, there is
> no cancellation of the reflected wave by the direct wave."
>
> The graphs accompanying the text show the cardioid+reflector does not
> suffer from the dip in gain displayed by the omni+reflector.
>
> The text is somewhat dated, but hopeful this information is still
> relevant.
>
> cheers
> Paul
>
>
> On 18/07/2007, at 7:07 PM, D Secomb wrote:
>
>> Hi all
>> I know this subject as been mentioned recently. It has been mentioned
>> that omni are in theory the mic to use in a reflector but several
>> members state a cardioid is the better type to use. Why?
>> What is the reason behind the preference? Is it gain, tone qualities,
>> low gain of sound outside the focus area or is there something else?
>> David
>
>
>
> "While a picture is worth a thousand words, a
> sound is worth a thousand pictures." R. Murray Schafer via Bernie
> Krause
>
> Yahoo! Groups Links
>
>
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