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Re: matching mic specs with recorder preamp -- thanks Rob D!

Subject: Re: matching mic specs with recorder preamp -- thanks Rob D!
From: "Rob Danielson" danielson_audio
Date: Sat Mar 29, 2008 9:09 pm ((PDT))
At 9:45 PM +0000 3/29/08, oryoki2000 wrote:
>In message # 32280, Rob Danielson wrote:
>
>>  Below is another chart with mic options for a
>>  Hi-MD recorder with its -124 dBu noise floor.
>>  <http://tinyurl.com/2uyox6>http://tinyurl.com/2uyox6
>
>Thanks, Rob! Your overlay of mics onto the chart from RANE really
>helps clarify who to match a mic to a recorder preamp.

Or to avoid a recorder that limits one's options!

>
>I have a couple of questions.
>
>1. On your Mics_16db.xls spreadsheet, I found specs for the Telinga
>EM-23: 14 dB(A), 10 mv/Pa. Do I correctly match it with a preamp
>noise floor of -118 dBu?

I believe the 10 mV/Pa figure was an early estimate. Gerry's test
suggested to me that the EMKS-23  is closer to 20 mV/Pa. I retain the
name "EMKS-23" to distinguish it Klas' first version and other
variations of the Primo capsule that are likely to come along.

I don't understand why the mics with lower sensitivity appear to have
lower effective noise on the Rane chart. I asked about this some time
ago; maybe someone knows.

I marked the mics in magenta that seem to fall on border between
having low enough self-noise" enough to use for ambience in quiet
locations and not (assuming a very good pre).

The charts can help one sense the relations between the mics and pre
noise but I wouldn't try to use the charts to project subtle
differences in noise performance.  There's a difference between
terminating a mic input with a 150 ohm resistor and listening to how
the noise sounds with a mic hooked-up, not to mention 25 mics
hooked-up.  I'm pretty familiar with the Hi-MD recorder and how many
mics sound on it so I was able to nudge lines on this chart and not
the others.

Its unfortunate that many low cost recorders can prevent folks from
enjoying the performance of the lower-cost, very low-noise mics we
know of.  I hope the charts can at least make this clearer.

>If this is correct, the EM-23 is among the best mics if you have a
>quiet preamp. Other mics in this category include
>
>Rode NT2000            -121 dBu
>Rode NT1A              -118 dBu
>Audio Technica AT 3032 -118 dBu
>Schoeps MK2 / CMC6     -118 dBu
>Sennheiser MKH-60      -114 dBu
>Sennheiser MKH-70      -112 dBu

Again, I wouldn't use the numbers deduced from the chart to
distinguish subtle noise performance differences-- especially for the
mics with very low or very high sensitivity. You would, for example,
be able to hear a large noise difference between a Rode NT1-A and an
AT3032, though the chart suggest the noise performance is very close.
The charts compound the errors and liberties we come across in
manufacturer specs too.


>Of this group, the EM-23 is the only mic that runs on low voltage
>"Plug-In Power" instead of 48V phantom power.
>
>2. Shouldn't the Schoeps MK2/CMC6 (-118 dBu) be in dark blue rather
>than medium blue letters, signifying its better performance?

I think the MK2/CMC6 is in dark blue, now. I might have changed it in
a revision I did earlier today. Refresh your browser. I wasn't trying
to make two blue values; just blue, magenta, red and brown typefaces.

>
>3. Thanks for including the Rode SVM in your chart I was unfamiliar
>with the SVM. It's a 9V battery-powered single-point stereo mic
>designed for use on a video camera.

If its based on their Video Mic (which the specs suggest) it should
be a nice stereo mic for the money. It should reduce self-noise in
the range of 5-10 dB(A) compared to the built-in electrets in the
point and shoot recorders. The only draw back is 6.3 mV/Pa
sensitivity and it features an X-Y array which isn't very exciting or
life-like as stereo goes, IMHO. Rob D.

>
>At a price of only $250, the SVM looks like a good match for "point
>and shoot" recorders like the Marantz PMD620, Edirol R-09, Tascam
>DR-1, and M-Audio Microtrack II, all of which have preamp noise
>performance around -110 dBu.


Thanks for your kind comments, Oryoki. Rob D.

>
>--oryoki
>


--






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