[Top] [All Lists]

Re: Shotgun mic Vs on-board mics

Subject: Re: Shotgun mic Vs on-board mics
From: madl74
Date: Thu Jul 17, 2014 4:06 pm ((PDT))
> I wouldn't think that impedance matching would be an issue with the
> PCM-M10. It has a very high impedance input (I think it's 20k ohms), so
> very little loss from  voltage division.


Think of it another way. A 200 ohm mic feeding into a 20K input is a 100
times impedance mismatch. If you fed the mic through a 1:10 transformer to=

get an impedance match, you would get a 20 dB rise in level (OK less 6dB).=

Life is not quite that easy, and the "noise optimum" match may be different=
but that has a long explanation. :-)

> I was thinking as I drove to work this morning that it makes sense that
> the overall signal would be higher using the built-ins on the PCM-M10
> because they are grabbing sound from all directions - they are
> omnidirectional microphones.
> Whereas the shotgun microphone (I wish we had
> a less violent word)

the director tube microphone

> is rejecting sound from the sides.

(trimmed neat description)

< '''
> But if the only sound source is, say, a single bird, and the "shotgun" is
> pointing right at it, then I would think the "shotgun" microphone would
> result in a higher level than the omnis, even if it is a little less
> sensitive.
> Does that make sense?

Yes, but it depends how you measure sensitivity. In a spec, it is with a
point source of sound. In the wild or in a reverberant space, we immediatel=
hear the benefit of a gunmic (UK term) but you won't see this in any tech

David Brinicombe

<Prev in Thread] Current Thread [Next in Thread>

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the naturerecordists mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU