Mic noise is one thing - mic preamp noise is something else.
If the output / Pa of a microphone is low, - then you have to use a lot of
preamp gain to get the signal up, but then you will hear the preamp noise!!
- not the mic noise!
If a mic has a 23 db self noise, its still has a 23 db self noise, even if
the output is high.
In practice you could be correct: A low output microphone with a good self
noise might give a poorer result than a high output mic with a poorer self
noise. But then it is because of preamp noise, and could be improved by
getting a better preamp.
The word "sensitivity" is also used by the Japs to describe self noise,
instead of dbA.
It's very confusing.
Klas
At 16:24 2005-02-15, you wrote:
>Citations about actual places, their sound levels, instrument specs
>and associated sound files like Klas's would be a great addition to
>an FAQ page wouldn't they?
>
>Another key factor that might also be added to the discussion about
>self noise is "sensitivity." The MKH's have both low noise and high
>sensitivity. The KM-23, though it has a very respectable rating of
>16dB(A) self noise, also has high sensitivity. The Sony MS-957 has a
>considerably higher value of noise @ 25 dB(A) but the presence of
>this noise in the signal is more apparent because its sensitivity is
>only ~6 mV/Pa and the record gain in quiet locations must be
>increased for sufficient record volume. The Shure WL-183 has
>22.5dB(A) self noise but its high sensitivity of 40 mV/Pa allows it
>to take greater advantage of its moderate self noise. The ideal
>combination of low self noise and high sensitivity contribute to a
>mic's ability to perform well under "very quiet" conditions. So,
>high "mV/Pa" numbers are good and low "dB(A)" numbers are good. Any
>number above 20mVPa is very good; any number below 10dB(A) is very
>good. Mic manufacturers' testing methods vary considerably, so the
>published numbers should only be regarded as ballpark "estimates"
>until proven in the field. Many terrific recordings have been made
>with modest gear that is perfectly suited for the situation--
>including sound levels. The placement of the mics in the sound field
>can make the recording sing or seem dull. Rob D.
>
> = = = =
>
>At 11:32 AM +0100 2/15/05, Klas Strandberg wrote:
> >A general statement which is almost true:
> >
> >Considering "sound quality", all microphones today are as good as the best
> >ones 20 years ago.
> >So don't worry about sound quality, frequency response etc. It's good
> enough.
> >
> >Then the noise problem:
> >
> >Listen to "My Garden" on telinga.com, click sound gallery.
> >The microphones in question had an inherent noise level of some 8-9 dbA.
> >That's low.
> >
> >In this category of mic's you will find the Sennheiser MKH series, the
> >telinga MPS1 series and all those recently marketed low-noise mic's using
> >the same China-made 1 inch capsule, like the CAD 179 for example. (Those
> >China capsules are very different from one another! You need to match them
> >to get a stereo pair!)
> >
> >If you replay such a recording at a reasonably low level, like in reality
> >or a bit louder, 10 dbA will not be audible at a recording like "my garden".
> >16 dbA will be audible, but not disturbing.
> >23 dbA will be disturbing and something which you will try to filter away.
> >Roughly.
> >
> >Considering an owl, 50 meters away, deadly silent around - 16 dbA will not
> >only be audible, but also disturbing.
> >
> >Noise is related to size. The bigger the membrane is, the easier it is to
> >make it low noise.
> >All 5 mm electrets have a noise level about 30 dbA or worse. All 10 mm
> >capsules have a noise level at about 26 dbA or worse. (All except one)
> >All 20 mm capsules, like Sennheiser ME-series and Telinga EM23, make about
> >16 dbA noise, or worse.
> >The Sennheiser MKH and Telinga MPS1 are here exceptional. They have 20 mm
> >membranes, but a noise which is only 10 dbA or better.
> >
> >Hope it helps a bit.
> >
> >Klas.
> >
> >
> >
> >
> >
> >
> >
> >
> >.
> >
> >
> >At 04:33 2005-02-13, you wrote:
> >
> >>Im one those who Walter refers in a previous thread
> >>
> >>"It could be very easy for this group to become nothing but technical
> >>discussions. But that would not be very attractive to new folks to
> >>nature recording. We need to get them hooked before we drop the ton of
> >>technological bricks on them. You can record well without understanding
> >>the terminology, though it's easier if you do understand the
> >>implications of that stuff."
> >>
> >>Even after followering to the group for several months now I still
> >>having a lot of trouble appreciating what is a good mic and how that
> >>relates to the dollar sign. From recent messages I'm not the only one.
> >>Some of this is terminology and unfortunitly I can not access the link
> >>on the groups home page which may help. Then there are varous
> > >specifacations one reads for example self noise, is very important but
> >>the difference between a mic with 25dB and 40dB are still figures.
> >>Something that I could relate to is how much closer am I going to get to
> >>that bird for the same recording. The some for self noise (how much
> >>extra hiss I'm going to hear in the background with an extra 10dB ) and
> >>there is sound to noise ratio. Other specifications such as output
> >>Impedance and Dynamic Range are just figures.
> >>
> >>I have looked at a number of sites that has a general advise on tools
> >>and methods. Also there have been a number of references on what makes
> >>a good mic in this group but there is hell a lot of messages to read to
> >>get a grasp of it all. I'm asking the impossible, can there be a set of
> >>guidelines amongst the group that would make an ideal mic, one that
> >>would do the job and those that will disappoint you for individual calls
> >>vs ambiance recordings. There is no need to mention specific makes of
> >>mics or other additions such as barriers as one needs to get a grasp of
> >>the basics befor being side tracked down another path. Some one could
> >>explain in practical terms what the varies specifications are. This
> >>maybe a useful reference for the home page.
> >>David
> >>
> >>
> >>
> >>
> >>
> >>--
> >>No virus found in this outgoing message.
> >>Checked by AVG Anti-Virus.
> >>Version: 7.0.300 / Virus Database: 265.8.7 - Release Date: 10/02/05
> >>
> >>
> >>
> >>
> >>"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:
> >
> >
> >
> >
> >
> >"Microphones are not ears,
> >Loudspeakers are not birds,
> >A listening room is not nature."
> >Klas Strandberg
> >Yahoo! Groups Links
> >
> >
> >
> >
>
>
>--
>Rob Danielson
>Film Department
>University of Wisconsin-Milwaukee
>
>
>
>"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:
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