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Re: DIY Parabolic Dishes.

Subject: Re: DIY Parabolic Dishes.
From: "Klas Strandberg" klasstrandberg
Date: Tue Oct 3, 2006 5:18 am (PDT)
No, every parabol rolls off after 10-12 kHz unless you don't want it to,
and make acoustic or electronic EQ.
Electronic EQ will add self noise and acoustic EQ of the microphone itself=

is extremely difficult to do in a good way.

Speaking about parabols and "sound quality" is difficult.

Some years ago, we had a gathering at Telinga with four of the best sound
"gurus" in Sweden. After recording, looking at theory and listening, - we
concluded that a parabol "sounds too good" to perform only what the graphs=

describe.
I usually rest my case with "a parabol is a parabol."

What I can see and hear, Telinga owners usually produce a LOT more useful
recordings than people using other ways to record. Research has been made,=

which should not have been made without the Telinga. This means, among
other things, that the 5 new bird species of the world which has been
discovered during recent years, have been discovered using Telinga's.
It means that all the recordings I have of "odd" bird-song, (some of them
the only recordings in the world (?)) - are made with a Telinga and would
not have been made otherwise..

It means that Mark Constantine and the gang could do what is now mentioned=

here on the list as:
Dave Gosney reviewed "The book is a terrific read and deserves to be bought=

by any birders who want to take their sound identification a whole leap
further forward. I can't remember the last time I was so impressed,
entertained and enlightened by a birding product. Birders everywhere should=

get this."

On the other hand it means that the best Nightingale recording in the world=

is not made with a Telinga or parabol, but by a person who has spent half
of his life making recordings of Nightingales only, and tested hundreds (??=

wouldn't be surprised...) of microphones. (He was probably the first one
going "halfways digital", using a bus with a 12 - 220 volt converter and a=

VHS recorder. (I'm not sure that he want's his name mentioned here.)

Klas.

At 01:17 2006-10-03, you wrote:
>Thanks for the graph it is very useful, I suspect that your speaker
>fell apart from 8,000 to 20,000 cycles. Right?
>
>Rich
>
>--- In  Klas Strandberg <>
>wrote:
> >
> > if you don't know.... there is a picture at
> > http://www.telinga.com/gallery/picture_gallery4.htm
> >
> > Observe the difference between the omni and the cardioid.
> > Also observe the shadowed +/-3db "average" frequency response of the
> > inwards facing cardioid: You can see roughly 25db (!!) between 300
>Hz and
> > 10 kHz.
> >
> > Klas.
> >
> > At 15:17 2006-10-02, you wrote:
> > >--- In  "John Hartog" wrote:
> > >
> > > > Thanks for your perspective.  If it's not too much trouble, please
> > > > email me the Sten Wahlstrom pdf =AD whenever you get the chance.
> > >
> > >I checked out this article when Mr. Knapp mentioned it some time ago.
> > >  It is available at most large university technical libraries for the
> > >cost of a photocopy:
> > >
> > >"The Parabolic Reflector as an Acoustical Amplifier", JAES Volume 33
> > >Number 6 pp. 418-429; June 1985
> > >
> > >Highly recommended!  If you aren't up to the math, you can just ignore
> > >most of it (the hardcore stuff is at the back anyways) and simply
> > >absorb the results.
> > >
> > > > http://home.att.net/~rsl/APPR1.htm
> > >
> > >This is not as comprehensive, or useful, as the Wahlstrom paper.
> > >
> > >If there is a PDF file of Wahlstrom's analysis, copyright should be
> > >figured out and it ought to be hosted somewhere.  Telinga ought to
> > >include it with their products as a kind of technical appendix.
> > >
> > >
> > >
> > >
> > >
> > >
> > >"Microphones are not ears,
> > >Loudspeakers are not birds,
> > >A listening room is not nature."
> > >Klas Strandberg
> > >Yahoo! Groups Links
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> >
> > Telinga Microphones, Botarbo,
> > S-748 96 Tobo, Sweden.
> > Phone & fax int + 295 310 01
> > email: 
> > website: www.telinga.com
> >
>
>
>
>
>
>
>
>"Microphones are not ears,
>Loudspeakers are not birds,
>A listening room is not nature."
>Klas Strandberg
>Yahoo! Groups Links
>
>
>
>
>
>
>

Telinga Microphones, Botarbo,
S-748 96 Tobo, Sweden.
Phone & fax int + 295 310 01
email: 
website: www.telinga.com







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