Topic: Mic Suggestions for nature work - Low Noise, < $1000 USD.

[Church-Audio]

Thanks Paul, more interesting reads. 

digifish

If you want binaural I would check out a pair of DPA 4090'S they have very little self noise and they are perfect for doing nature recording. But you must have a good high pass filter on them.
They are very flat very natural sounding mics.

Chris

[spzkt]

If you want binaural I would check out a pair of DPA 4090'S they have very little self noise and they are perfect for doing nature recording. But you must have a good high pass filter on them.
They are very flat very natural sounding mics.

Chris

Hi Chris

The specs I've seen on the DPA-4090's give self noise as 23 dB(A) which seems pretty noisy in comparison with other mics that have been discussed [<16dB(A)].  Are DPA measuring differently to other manufacturers which makes the mics look nosier on paper than they actually are in use?

cheers
Paul

[Church-Audio]

If you want binaural I would check out a pair of DPA 4090'S they have very little self noise and they are perfect for doing nature recording. But you must have a good high pass filter on them.
They are very flat very natural sounding mics.

Chris

Hi Chris

The specs I've seen on the DPA-4090's give self noise as 23 dB(A) which seems pretty noisy in comparison with other mics that have been discussed [<16dB(A)].  Are DPA measuring differently to other manufacturers which makes the mics look nosier on paper than they actually are in use?

cheers
Paul

DPA always "averages" there specs out because they make so many mics.. for the price I dont think there are to many mics that have that kind of noise floor.. And the other main issue is how accurate are the specs that these guys are printing? I trust DPA's Specs because making measuring equipment is what they do.. They make the equipment that is the industry standard for microphone measurement and calibration and noise measurements.

[spzkt]

DPA always "averages" there specs out because they make so many mics.. for the price I dont think there are to many mics that have that kind of noise floor.. And the other main issue is how accurate are the specs that these guys are printing? I trust DPA's Specs because making measuring equipment is what they do.. They make the equipment that is the industry standard for microphone measurement and calibration and noise measurements.

There is a thread over at gearslutz which discusses the 4090 and the claims regarding it's self noise.

http://www.gearslutz.com/board/remote-possibilities-acoustic-music-location-recording/115897-dpa-4090-truth-about-its-noise.html

from those discussions it does sound like it's a really nice mic, just not especially quite. These guys are talking about classical recording and listening to the clips posted to the thread didn't really give much of an idea how suitable they would be for nature recording.  Based on comments made in the above thread I'd be hiring a pair to test for myself in the field before committing to purchase.

cheers
Paul
 

[wbrisette]

from those discussions it does sound like it's a really nice mic, just not especially quite. These guys are talking about classical recording and listening to the clips posted to the thread didn't really give much of an idea how suitable they would be for nature recording.

This is similar to the Earthworks QTC-1/QTC-40/QTC-50 mic. They are awesome for recording classical music, but when you look at the self-noise, it's just way too much for nature recordings.

Wayne

[Church-Audio]

DPA always "averages" there specs out because they make so many mics.. for the price I dont think there are to many mics that have that kind of noise floor.. And the other main issue is how accurate are the specs that these guys are printing? I trust DPA's Specs because making measuring equipment is what they do.. They make the equipment that is the industry standard for microphone measurement and calibration and noise measurements.

There is a thread over at gearslutz which discusses the 4090 and the claims regarding it's self noise.

http://www.gearslutz.com/board/remote-possibilities-acoustic-music-location-recording/115897-dpa-4090-truth-about-its-noise.html

from those discussions it does sound like it's a really nice mic, just not especially quite. These guys are talking about classical recording and listening to the clips posted to the thread didn't really give much of an idea how suitable they would be for nature recording.  Based on comments made in the above thread I'd be hiring a pair to test for myself in the field before committing to purchase.

cheers
Paul
 

Trying to compair an ecm 8000 to any DPA mic IS A JOKE. I have had the DPA 4007 and compared it to the 4090 now the 4090 and it was pretty close.. But the 4007 had much less noise at the same gain settings.. But again that's a 2k microphone... It was hardly a fair comparison.. But I dont know of many mics in the price range of $469 each that have as good of a frequency response and as low of a noise floor..

[spzkt]

16 or 17dB self noise can be pretty intrusive in nature recording, especially when coupled with low sensitivity.

[Church-Audio]

16 or 17dB self noise can be pretty intrusive in nature recording, especially when coupled with low sensitivity.

Show me a mic that costs $500 that has a REAL self noise of 17 db please

[spzkt]

Show me a mic that costs $500 that has a REAL self noise of 17 db please

i've never said such a mythical beast exists 

That said, the at3032 does seem pretty quite when compared to an ME66/K6 (10dBA) so who knows.

[digifish_music]

Show me a mic that costs $500 that has a REAL self noise of 17 db please

i've never said such a mythical beast exists 

That said, the at3032 does seem pretty quite when compared to an ME66/K6 (10dBA) so who knows.

Rode NT1-A

5 dB

http://www.rodemic.com/?pagename=Products&product=NT1-A

$199 Yes I know it's probably not what you meant

However I have been itching to do something like this with them...

http://www.uwm.edu/~type/audio-reports/Rode_NT1-A_Mics/NT1-A_index.htm



digifish

[spzkt]

Self-noise is in reference to an equivalent SPL signal at the capsule, and is thus independent of the sensitivity rating.  Also, given the variation in manufacturers' noise rating protocols, at a minimum the noise rating should be noted as unweighted, A-weighted, etc, where possible.

Yes all that is true. I won't argue

The noise floor of the mic is obviously fixed by the design and doesn't vary with the SPL. The sensitivity relates to the level of output given a specific SPL.

So if you have two mics with the same self noise but different sensitivity, the mic with the higher sensitivity will give a higher signal to noise ratio than the mic with lower sensitivity. Turning up the preamp gain to compensate for the lower sensitivity raises the noise floor along with the signal.

If you match playback levels for records made with these two hypothetical mics, the self noise is going to be at a higher level and be more obtrusive on the recording made with the lower sensitivity mic.

and thanks digifish how could I forget the "locally made" NT1A!!

cheers
Paul



 

[guysonic]

AS mentioned, different mics have different sensitivities meaning preamp output level will vary for the same intensity of sound source at identical preamp gain. 

To make noise graphs meaningful, dB output level from calibrated sound source input at same preamp gain should be noted for each mic tested, and graph should be adjusted so relative noise comparison can be made for each mic.  Also, baseline plot of noise out of preamplifier loaded with ~100 ohms input at used gain should be shown on the graph. 

Without these considerations such graphs are meaningless to show which mics are indeed quieter over bandwidth.

Also, Eric Benjamin graph shows huge room 60/120 Hz electrical noise pollution occurring so at least lower frequency plots of noise over bandwidth characteristic is also meaningless.  These tests should be done inside 'screen room' environment that excludes such interferences.

[digifish_music]

AS mentioned, different mics have different sensitivities meaning preamp output level will vary for the same intensity of sound source at identical preamp gain. 

To make noise graphs meaningful, dB output level from calibrated sound source input at same preamp gain should be noted for each mic tested, and graph should be adjusted so relative noise comparison can be made for each mic.  Also, baseline plot of noise out of preamplifier loaded with ~100 ohms input at used gain should be shown on the graph. 

Without these considerations such graphs are meaningless to show which mics are indeed quieter over bandwidth.

...he did/does...

http://www.uwm.edu/~type/audio-art-tech-gallery/pages/page_38.html

[Church-Audio]

Show me a mic that costs $500 that has a REAL self noise of 17 db please

i've never said such a mythical beast exists 

That said, the at3032 does seem pretty quite when compared to an ME66/K6 (10dBA) so who knows.

Rode NT1-A

5 dB

http://www.rodemic.com/?pagename=Products&product=NT1-A

$199 Yes I know it's probably not what you meant

However I have been itching to do something like this with them...

http://www.uwm.edu/~type/audio-reports/Rode_NT1-A_Mics/NT1-A_index.htm



digifish

Um you cant do noise measurements like that.. They must be done in a vacuum or in an anechoic chamber.. But not in a "quiet room" and where is your baseline measurement that shows the noise of your preamp? how are you subtracting your self noise of your signal chain?

Chris

[Church-Audio]

So if you have two mics with the same self noise but different sensitivity, the mic with the higher sensitivity will give a higher signal to noise ratio than the mic with lower sensitivity. Turning up the preamp gain to compensate for the lower sensitivity raises the noise floor along with the signal.

If you match playback levels for records made with these two hypothetical mics, the self noise is going to be at a higher level and be more obtrusive on the recording made with the lower sensitivity mic.

I'm sorry, that is wrong.  Sensitivity is independent of noise rating.  It is true that there tends to be a relationship, because a larger diaphragm capsule tends to have greater sensitivity, and therefore greater signal to noise of its following circuitry.  But once you reach the level of reading a mics' specs, assuming two mics use the same noise rating, a direct comparison of noise ratings SHOULD be possible, without any adjustment for sensitivity.  If it is not, it has nothing to do with sensitivity, and everything to do with variation in manufacturer test methods.  If you have a noisy preamp, you would probably select a more sensitive mic, but that is a characteristic of your preamp, not the microphone.

Consider that sensitivity of a mic can be highly influenced by not only the capsule, but also the amplifier circuit.  I can take WM61A, for example, and make the sensitivity nearly anything you want, within reason.  Let's say -45dBV/Pa to -28dBV/Pa, without any following amplifier circuit, just the internal FET.  If I decide to add an internal amp, I could make it something completely silly like -10dBV/Pa.  Now those values will have implications for various parameters, but the noise will be the same (it would actually get a little noisier if I added the internal amp).

Take a couple of Shure mics mentioned already, well one anyway, along with another:  SM81, and KSM141.  The SM81 is rated -45dBV/Pa and 16dBA.  The KSM141 is -37dBV/Pa, 14dBA.  How much noisier is the SM81 (assuming a preamp quiet enough to stay well below those ratings) than the KSM141?  2dB, not 8dB, not 10dB.  Test it and see.

If you really need an extremely quiet condenser mic, you need a large diaphragm mic.  That's why I am suspicious of any claim that a small diaphragm mic is really 8dBA.  There are physical laws at play that make such performance difficult, to say the least.

I have to agree with you here Jon. Noise is Noise.. The output of the mic is not a factor in the mics self noise.. It is a factor in the flawed tests that were conducted here. Noise must be measured properly in order to be meaningful I dont have the gear to measure self noise of my mics I dont know to many companies that are my size that have that ability.. Its a very hard measurement to make. These guys are are right in saying that a mic with less sensitivity will need more amplitude to produce the same output level, and that in and of it self will mean that your noise will increase due to the increase in gain. But that's not what self noise is about.