probably the best infrasonic mics ever made are the Sennheiser MKH-110. Now=
they are out of production, though you can sometimes find used or
refurbished units on eBay.
Other than being sensible down to 1 Hz, they are low noise with excellent
flat response to more than 20 kHz.
Most portable DATs can be used for recording. Normally DAT recorders work=
well down to 7-10 Hz. If you can use a laptop or a PC you can also use good=
sound cards.
As infrasounds are outside the specification limits of any consumer
equipment, it is important to check responses with a sound generator to be=
sure to be able to capture the frequencies you're interested in.
If you record with a PC it is easy to reveal infrasonic patterns by
speeding up the playback of your files. For example, you can record at
48kHz to get full audio bandwidth and the play at 192kHz, if you can, to
hear all those low frequencies normally not audible.
With suitable software you can speed up even more, 10 times for example, by=
filtering and resampling. This is also required for analyzing infrasounds
in detail.
Gianni
At 13.57 07/02/2004, you wrote:
>Hi Dan Dugan:
>
>I have written five times to enquire about the
>following. Will anyone give answer to it?
>
>Dear Mr. Dugan:
>
>Greetings from India. I recently joined for the nature
>recordist group. I am a wildlife researcher primarily
>focussing on large mammals. I am very keen to record
>the sound of the birds and the communication of the
>mammals especially the infras sound.
>
>I have written twice to this group to suggest the
>basic equipment required for recording the call of the
>birds and infra sound mic, recorder and to analyse the
>data later, or any other related accessory that I have
>to take.
>
>Would you kindly give me a feed back on what kind of
>equipment is required for my purpose of recording and
>what would be the approximate cost of the same. I
>would really appreciate it very much if you could give
>the feed back at the earliest.
>
>Many thanks
>
>Best regards
>Bhaskar
>
>
>
>__________________________________
>Do you Yahoo!?
>Yahoo! Finance: Get your refund fast by filing online.
>http://taxes.yahoo.com/filing.html
>
>
>"Microphones are not ears,
>Loudspeakers are not birds,
>A listening room is not nature."
>Klas Strandberg
>Yahoo! Groups Links
>
>
>
>
--------------------------------------------------------------
Gianni Pavan
Email
Centro Interdisciplinare di Bioacustica e Ricerche Ambientali
Universita' degli Studi di Pavia
Via Taramelli 24, 27100 PAVIA, ITALIA
Tel +39-0382-507874
Fax +39-02-700-32921
Web http://www.unipv.it/cibra
________________________________________________________________________
________________________________________________________________________
|