At 18:20 2005-09-03, you wrote:
>At 12:34 PM +0200 9/3/05, Klas Strandberg wrote:
> >At 17:41 2005-09-01, you wrote:
> >>Do you think we'll be able to get a sensitivity number or even an
> >>accurate range of mV/Pa : dbB(A) combinations that will apply to
> >>DAT/MD/HiMD mic preamp's in general? I tested the Rode NT-1A's with
> >>the Rolls phantom power supply with these recorders:
> >>
> >>NH900 HiMD
> >>Sharp MT-90
> >>Sony D-7
> >>Sony TRV-900 (video camcorder)
> >>
> >>and found that the NH-900 is significantly quieter than the other
> >>recorders with the Sharp MD being the noisiest.
> >
> >
> >That doesn't surprise me. Sharp got some stupid ideas from last years
> >models, the input PIP current regulator, for one.
>
>The MT-90 (and similar MT190) was still in
>production about four years ago, prior to the
>voltage regulator change. Whether the newer sharp
>models or quieter whether the other older
>recorders are on par is unknown.
I have never seen the MT-90 in Europe. I speak of Sharp in general. Perhaps=
they were the noisiest even before last years changes. As Telinga mic's
overrides the Sharp noise, I have never cared to find out.
> >
> > From my perspective: Many customers use a "Walkman" type MD. Sharps, t=
oo.
> >I want to provide a microphone which output is high enough to override t=
he
> >input noise of such a machine.
> >All Telinga mic's (without dish, of course) make about 14 db(A) noise. W=
ith
> >the capsules I use, and the FET-IC's I use, this comes free. Without any
> >complicated circuitry, all Telingas override the input noise of even a l=
ast
> >years Sharp. I know that, because I use the poor Sharp machines as "mini=
mum
> >reference".
> >
> >But when people here are choosing other mic's, I think there would be at
> >least some reference, at least referring to the NH900.
>
>There seems to be consistency with the Sony HiMD
>recorders coming off the line so far-- the mic
>pres are remarkably quiet. It might be a good
>time for A/B comparisons of recent model Sharps
>and pre HiMD Sonys. If a significant performance
>difference can be established, $160 for a new
>recorder is not an expensive upgrade given the
>other alternatives.
>
>[Off topic aside. Once Sony establishes a format,
>they start dropping record side features in the
>lower cost machines forming a larger gap between
>"pro" and "consumer" and a place for a
>domo"prosumer" tier. They do things like move manual
>record gain into the "prosumer" tier "offering"
>consumers auto gain or remove the mic jack, or
>hide it in a 16 conductor that one can only get
>attached to a very bad mic for $70. They just did
>this with consumer level DV video. I suspect the
>current 900, 910 and RH10 models have features
>that might be missing in the next crop of
>$160-$200 units. One clue is first prosumer model
>HiMD with mac compatibility (telling in itself),
>requires one to buy a mic with 34dB(A) self noise
>and 10mV/Pa sensitivity.]
>
> >
> >That is: If you use a NH900 - then you can use any electret providing mo=
re
> >than xx mV/Pa with a self noise lower than 14 db(A). If you do, you don'=
t
> >have to worry about the NH900 input noise. The noise you get, is from th=
e
> >electret.
>
>Makes sense in theory. Can I ask you how you came up with 14dB(A)?
I measured, just as one should. I have the Sennheiser meter with the
normalized filters.
>Are you addressing electret mics only in this
>summary? I mean, they have higher self noise as
>rule compared to condensers.
No, not only electrets. But I think that the ones going for phantom powered=
condensor mics (usually) have other recorders than Walkman types. They can=
(probably) accept a lower mv/Pa and still be below the mic noise level.
> >
> >Or vice versa: If you use a Sharp MT-90 - then a 14db(A) microphone must
> >provide at least yy mV/Pa to override the Sharp input noise.
>
>I don't follow. You mean we don't know the
>sensitivity "yy" value as yet? Rob D.
Correct - we don't know the needed "yy" value for a 14 db(A) microphone to=
override the Sharp noise. Or whatever noise.
Or?? If someone knows how to calculate this from given specs, please do. I=
might be wrong.
Klas.
> >Klas.
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >>I've been thinking about the min mV/Pa question since you posed it a
> >>while ago. I came across table #3 on
> >>http://www.rane.com/note148.html. With this chart, it seems like we
> >>might be able to take what we know about the NH900 performance to
> >>estimate the noise floor of NH900 mic pre for starters. I'm pretty
> >>confident that the noises I'm hearing when I hook up:
> >>NT1A->Rolls->NH-900 are close to a 50-50 blend of mic and NH900 mic
> >>preamps. Applying the NT1A's specs* to table #3, I get ~-118 dBu for
> >>the NH900 HiMD mic pre, but I'm blindly following the chart and other
> >>aspects of the chart confuse me. Rob D.
> >>*6dB(A); 25mV/Pa
> >>
> >> =3D =3D =3D =3D =3D
> >>
> >>At 11:34 AM +0200 9/1/05, Klas Strandberg wrote:
> > > >With only 5,6 mV / Pa I am certain that you get MD preamp noise.
> >> >You need too much gain.
> >> >
> >> >That is what I would like to discover: At which output / Pa does a
> typical
> >> >MD preamp noise "take over".
> >> >
> >> >Klas.
> >> >
> >> >At 04:44 2005-09-01, you wrote:
> >> >>At 5:07 PM -0700 8/31/05, Dan Dugan wrote:
> >> >> >Lou Judson wrote:
> >> >> >
> >> >> >>Curiosity took me to the
> >>Soundprofessionlas website this morning, and I
> >> >> >>see they have some closeouts on their stereo pairs already
> wired for
> >> >> >>PIP - $49 instead of 129. Has anyone compared theirs to such as=
the
> >> >> >>Shure 183s? Ths ones on sale now are cardioid, yet for some of=
> what I
> >> >> >>do they would be ideal.
> >> >> >>
> >> >> >>http://www.soundprofessionals.com/cgi-bin/gold/item/SP-CMC-22
> >> >> >
> >> >> >It was Sound Professionals who turned me on to the 183s, just be=
fore
> >> >> >they changed to something else.
> >> >> >
> >> >> >Sharon Perry uses SP cardioids, which are Audio-Technicas, for h=
er
> >> >> >vest. Gain is about the same as 183s, but the cables are quite
> >> >> >microphonic. Don't know if that's the type they're currently usi=
ng.
> >> >> >
> >> >> >If the s/n of "58" is correct, 94-58 =3D 36dB, pretty high.
> >> >>
> >> >>and a (lower) sensitivity of 5.6mV/Pa (high mV/Pa #
> >> >>[sensitivity.output] is good; low dB(A) # [self noise] is good.)
> >> >>
> >> >>compare to:
> >> >>Panasonic WM61a capsule 32.5 dB(A)* 18 mV/Pa **
> >> >>spec sheet: http://tinyurl.com/8g4l9
> >> >>Cost $16.21 for 10 + shipppiing http://www.digikey.com/ and enter
> >> >>"wm-61a" into parts search.
> >> >>You can solder a workable set to run on MD/HiMD plug in power for a
> >> >>few bucks more http://webpages.charter.net/tidmarsh/binmic/
> >> >>
> >> >>*Based on Eric B's test on file on the micbuilders list.
> >> >>http://tinyurl.com/8tkt4 **Is this sensitivity number right? Eric's
> >> >>test seems to confirm Panasonic's figure of (0dB=3D1V/Pa, 1kHz)
> >> >>-35+/-4dB.
> >> >>I need to learn how to make this conversion.
> >> >>
> >> >>and for reference:
> >> >>ShureWL-183 22 dB(A) 29 mV/Pa
> >> > >Rob D.
> >> > >
> >> >
> >> >Telinga Microphones, Botarbo,
> >> >S-748 96 Tobo, Sweden.
> >> >Phone & fax int + 295 310 01
> >> >email:
> >> >
> >> >
> >>
> >>
> >>[Non-text portions of this message have been removed]
> >>
> >>
> >>
> >>
> >>"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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