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Re: Mic cables and mic impedance

Subject: Re: Mic cables and mic impedance
From: Vicki Powys <>
Date: Sun, 02 Jun 2002 15:08:13 +1000

Syd and All,

I only know the basics here, but low impedence equipment usually has those
3-pin canon plugs and sockets and is "professional" style equipment, while
high impedence gear uses mini-plugs and sockets and is "consumer" style.

If you use shielded professional Cannare cables you should be fine unless
the bush rats eat it.  There was some discussion in WSRS about powering the
mic at one end of the cable, or the other.  Can't remember which was best.
But if your mic is to be placed close to the lyrebird, you should get a good
result either way.  Powering the mic from the recording end is preferable so
that you don't disturb the lyrebird.

Klas will have to advise you about a separate power supply for the Telinga
mic, I am sure it would be possible.

But you might be better just to sort out more power options for the Tascam?
Mics don't take much battery power to run them, in my experience.


Vicki Powys
Australia



on 1/6/02 9:03 PM, Syd Curtis at  wrote:


> 
>  I'm so technically ignorant that I
> don't even understand what impedance is.
snip
> 
> When I started recording bird song (06:00 hrs Oz EST, June 21, 1968) I had
> the good fortune to have been well advised on the recorder: I had a Uher.
> (Recently overhauled, and apparently working well.  How's that for a 30
> year-old piece of technology!)
> 
> I was also advised that to get a good recording of a lyrebird one needs to
> place a mic on a long lead, where the bird is going to sing, and for this,
> one must use a LOW IMPEDANCE microphone.  The Uher mic I got with the
> recorder worked OK with 50 metres of cable, and so too did a couple of
> Sennheisers I got later.  I assumed they must be low impedance.
> 
> Of the shotgun Sennheiser (MKH-815), a friend said that what the Sennheiser
> people  don't tell you, is that you can put the power supply at the recorder
> end of the long cable.  I have soldered up a few connectors, but I thought
> of the cost of the mic. and the depth of my ignorance of electronic matters,
> and didn't try!
> 
> A couple of years ago I got a Tascam DAT recorder and have successfully used
> a small Sennheiser ME 20 on the long cable with it.  But I now have the
> great good fortune to have a Telinga mic which is just so much better.  I
> feel sure that with the reflector it will be a definite improvement over a
> shotgun mic for recording lyrebirds at a distance - if the poor
> drought-stricken lyrebirds sing this year.
> 
> But can I use the Telinga mic. on a long cable?  Is it of low impedance - if
> indeed that is critical?
> 
> If so, is it a matter of getting a suitable cable and connectors and still
> using the Tascam's phantom power?  Or is it possible to get an external
> power source for the Telinga?  The latter, I would prefer: lyrebirds
> sometimes sing for an hour or more, and battery life becomes critical.  One
> doesn't wish to have to change a battery in the middle of a performance:
> Murphy's Law applying, that would be exactly when something unusual
> happened.
> 
> I would use the Services of Music Lab, a local electronics firm, to make the
> cable, and external power supply, if that is possible.   Tascam/TEAC are
> pretty big in the music industry, and I'm sure Music Lab would be familiar
> with the Tascam recorder.  But not the Telinga microphone.  And in the music
> industry they probably don't get much call for recording 50 metres away from
> the microphone(s) and kilometres away from any power supply - 240 V mains AC
> or even motor vehicle 12 volt DC.
> 
> It usually takes me a few days study of an individual lyrebird to get him
> singing at my mic.  And if I've gone to that much trouble, it would be great
> to be able to take advantage of the outstanding Telinga quality.
> 
> Any advice would be most gratefully received.
> 
> TIA
> 
> Syd Curtis (Brisbane, Australia)
> 
 



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>From   Tue Mar  8 18:22:25 2005
Message: 13
Date: Sun, 02 Jun 2002 00:24:52 -0400
From: Walter Knapp <>
Subject: Re: Re: MORE MOORE HHB

Walter Knapp wrote:

> Just to complicate it a bit, I only set the desired window as between
> the loudest part of the wanted call and the mic's noise level. But, for
> most environments if we are using quality mics the environment's
> background is noisier than the mic. For instance in the disk full of
> river frog recordings I'm processing from the trip, the insects form the
> steady background, and they are between -60 dB & -40 dB on the
> Portadisc's meter. The river frog calls I want barely get better than
> that. But come through quite strongly as the Telinga helps focus on
> them. I've got to send a clip to a couple folks, so will put up a link
> when I get it done as I'll probably have the clip up for a week or two.
> Just in case you are interested. The dynamic range of that environment,
> calls and all was very narrow, maybe only 30-40 dB.

Here's the link, it's about 800k and a mp3. Fairly typical of what I
got. There are bird-voiced treefrogs and green/bronze frogs as well as
the river frogs. From there you are on your own as to what the sounds are:
http://wwknapp.home.mindspring.com/naturerecordists/2002-002-17S.mp3

Telinga Pro V with Dat Stereo mic, HHb Portadisc.

Walt



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