Klas--
Thanks much for taking time to spell out your
priorities and specific testing methods.
I toally agree that the CAD 179 is not on par
with the Sennheiser mics even though CAD claims
comparable self noise figures. The 179 is one of
about a dozen new mics out there that advertise
"extremely low noise." At least one mic lives up
to the claim in my opinion, at least one doesn't.
2 down, 10 more to go. I'm finding the side by
sde comparisons really telling and useful and
when recordists have a good sense of gear really
performs, it makes the manuf's and dealers think
twice about fudging. Customer confidence in a
product line is worth a lot. I wish there were
more side by side comparisons in the trade
magazines but I guess they survive on the
advertisements, truthful or not.
I recently tested the NT1-A's, MBh) 603's,
Sennheiser mkh 30/40 on MP2, Micpre and & 744
pres.
m("sbcglobal.net/lst?.dir","//f2.pg.briefcase.yahoo.com/bc/rob_danielson");=3D=">http:=3D=
/Tests&.view=3Dl
"MidtoLowNoiseMicsPre.mov" 3.7mb
This link work better for some browsers:
m("sbcglobal.net/vwp2?.tok","//f2.pg.briefcase.yahoo.com/bc/rob_danielson");=">http:=
=3Dbc431TVBHNBPatgP&.dir=3D/Tests&.dnm=3DMidToLowNoiseMicsPres.mov.mov&.src=
=3Dbc
[ts hard to tell which links other users/browsers
have sucess with the sbc site. Feel free to email
me if it works or doesn;t work for you .Specify
the browser/version you are using. IE is supposed
to work best.]
The NT1-A has been tagged as ill suited to the
field. To this I can only respond, gosh, how did
the audio signal get to the recorder for these
200+ hours of material I'm working with?
Rob D.
At 2:28 PM +0200 5/12/05, Klas Strandberg wrote:
>!/ That is a relevant question - you have to identify the noise by it's
>character. When working with a mic in the lab for several days, you learn
>to hear what the noise sounds like, just like you learn to hear what a
>certain bird sounds like. Usually it is not difficult, but I admit that I
>make temporary mistakes.
>
>A simple way to learn the difference is to put an attenuator on the mic an=
d
>lower the mic self noise until you start to hear the MD / DAT /Edirol
>/whatever mic amp noise. Then you can hear the difference.
>The FET-IC which I use for all mics has a noise which is low in frequency,
>while the MD/DAT/Edirol inputs have a noise which is much more like white
>noise. Sometimes you can hear how the mic noise and the preamp noise is
>added, so that a low frequency noise from the mic is added to a high
>frequency noise from the mic amp.
>
>2/ When reading noise figures, consider that "A-weighted" noise or
>"CCIR-weighted" noise means that one has compensated for the frequencies
>which are most audible to the human ear.
>For naturesound recordists there should be another way to "weight" a noise=
,
>compensating for the noise which is most masked by nature atmosphere. A
>high frequency noise can be audible "on top" of the atmosphere, while a lo=
w
>frequency noise is masked by it and not possible to hear at all.
>
>3/ When I send my postings on this list, I don't feel that I am understood=
.
>I do not succeed in finding the right words for my logic. Let me try this =
one:
>
>Suppose a microphone has a self noise of 16 db(A). Fine. That cannot be
>changed by any pre-amp.
>Then the question must be: "How sensitive (output =3D mv/Pa) must that
>microphone be to "noise-dominate" over the MD/DAT/ Etc mic input noise?
>That is the question which needs to be answered!
>
>I mean - the noise you hear should always come from the mic!!! The mic mus=
t
>always be the weakest link in the chain!
>
>4/ Sensitivity must be presented as mV/Pa, NOT -db, whatever - as there is
>too much cheating on the market, using different reference levels for the
>db measuring.
>I spent two hours on the web a few days ago (with broadband- finally!! her=
e
>in the woods!!) - to straighten out my questions about "sensitivity"
>expressed as "db". I found myself in a total mess of different standards.
>If you like to try - please visit
>http://www.acoustics-noise.com/dBA-B-C-D-U-G-U-AU-tables.shtml for example=
.
>
>When the data sheet says: "10 mv/Pa at 1000 Hz" - fine, that is a fact! On=
e
>can understand it. But when it says: "Sensitivity -64" db or something, I
>don't care about it. I don't see any good reason why somebody should leave
>an established and accurate expression (mV/Pa) in favor of a strange figur=
e
>(db), unless there is fraud going on.
>We must all understand that: When one manufacturer starts manipulating wit=
h
>data, even lying, all the others have to follow. Or die.
>
>Example: Walt helped me to buy a CAD 179. It is a good mic for it's price,
>though bulky and ugly and not good for field work. But it's noise
>presentation?? It says 10 db(A)!!! No way!! In it's omni-position, it is
>much noisier than a MKH20 which presents the same 10db(A), and the noise i=
s
>more "sparkling"!
>Even Neumann presents a similar (China made) mic with a self noise of
>7db(A). So why is it audibly noisier than a MKH??
>
>Klas.
>
>
>
>
>
>
>
>At 14:41 2005-05-11, you wrote:
>>Klas
>>How are you Mic picking noise from pre-amp noise?
>>
>>Klas Strandberg wrote:
>>
>> > A Telinga microphone boosts sensitivity and low noise. It sacrifices =
high
>> > sound pressure level and in one case (stereo DATmic) also linearity.
>> >
>> > Other mic's don't do that. Therefore, if you want to combine "the Tel=
inga
>> > qualities" with high sound pressure level and linearity, - you are
>> > stuck in
>> > the Sennheiser MKH system. There is no way around this problem.
>> >
>> > I don't know about the Rode mic's, except that they are made by a
>> > Swede who
>> > emigrated to Australia and sold here, too, in shops for musical
>> > instruments
>> > and vocals.
>> >
>> > What I know about microphone tests is that is is soooo easy to make
>> > errors.
>> > Even the most careful tests which I (and J=F6rgen) have made, have
>> > proved to
>> > be wrong after a few days only. It is like you have to "get acquainte=
d"
>> > with a certain microphone over a long time before you can judge about
>> > it. I
>> > have listened to mic noise one evening and judged it as okay, next da=
y I
>> > find it too high... And vice versa!
>> > And most of the tests which I do have to be repeated over and over ag=
ain.
>> > Only when I get the same result at least five, six times - then I am
>> > pleased with the reliability.
>> >
>> > I can only claim two things:
>> >
>> > If you hear microphone noise, then you cannot lower this noise by usi=
ng a
>> > preamplifier. It is there, and all you can do is amplify it.
>> > If you hear MD / DAT amplifier noise, you have the wrong microphone f=
or
>> > nature sound recording. Or - rare - you have a very, very bad microph=
one
>> > preamp, must worse than any common MD mic input.
>> >
>> > I tested again today: Used a 10 mm PIP electret and a EM23PIP into
>> > different Sharp MD's which I have + the Edirol R1. The noise I could =
hear
>> > came from the microphone FET and not from the MD / Edirol mic input a=
mp.
>> >
>> > A preamp into the line inputs will only amplify this FET noise.
>> >
>> > I don't deny that others have other experiences, but I can't explain =
it.
>> >
>> > When reading data sheets with noise figures and frequency curves, don=
't
>> > forget that those figures were measured with a brand new microphone,
>> > inside, room-temperature and a suitable humidity. Age, low temp, impa=
ct
>> > from use in humid areas, dust and bacteria (even fungus!) will affect
>> > those
>> > figures by many db.
>> >
>> > Klas.
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> >
>> > At 20:07 2005-05-09, you wrote:
>> > >Hi Klas-- I apologize for my error. Were you able to download the
>> > >test? There's a noticeable increase in noise with the NT-4 that I'd
>> > >like to hear your thoughts about. The MP2 preamp does seem to lower
>> > >the noise with the NT-4 and the curious thing is the NT3 and Nt4 bot=
h
>> > >have very similar self noise (16 and 17dBA) and exact sensitivity
>> > >specs (12dBA). I can email it to you too, its 2.3 mb. Rob D.
>> > >
>> > >At 6:47 PM +0200 5/9/05, Klas Strandberg wrote:
>> > > >At 23:55 2005-05-04, you wrote:
>> > > >>I went down to fix dinner and realized that my logic is wrong abo=
ut
> > > > >>being able to deduce any Mic Pre noise figure from the test. Sor=
ry.
>> > > >>With the NT3, if the noise through the HiMD mic pre and the
>> > > >>workaround MP-2 is the same, what we're hearing is likely the noi=
se
>> > > >>just from the NT-3.,..I have to go back to making dinner, but why
>> > > >>does the NT-4 through the workaround MP2 have less noise? Where w=
ould
>> > > >>the noise be coming if not from the HiMD mic pre? Rob D
>> > > >
>> > > >
>> > > >How wonderful isn't it with people who has such a free-running
>> > brain that
>> > > >it realized a previous error while fixing dinner....
>> > > >
>> > > >I still don't know for sure what is right and wrong in this topic,
>> > but I
>> > > >hope that my brain will solve it while making dinner next time. Ha=
ve to
>> > > >wash my car tomorrow. Perhaps then...?
>> > > >
>> > > >Until then I repeat: If you hear noise, you can never lower this
>> > noise by
>> > > >using a preamp.
>> > > >
>> > > >Klas.
>> > > >
>> > > >
>> > > >
>> > > >
>> > > >>Rob D: wrote and realized soon afterwards,..
>> > > >>
>> > > >> >
>> > > >> >
>> > > >> >At 12:22 PM +0200 4/21/05, Klas Strandberg wrote:
>> > > >> >> >Since the 957 already terminated in an 1/8th mini jack,
>> > and uses
>> > > >> >>>plug-in power? Or maybe it's battery operated? I'm not sure
>> > how much
>> > > >> >>>you'd gain by adding a preamp. I think we're mainly referrin=
g to
>> > > >> >>>phantom powered mics using external preamps. That being said=
,
>> > I know
>> > > >> >>>often the minidisc mic input isn't the cleanest, and if you
>> > can go in
>> > > >> >>>line level, you'll bypass some of the noise.
>> > > >> >>
>> > > >> >>
>> > > >> >>I clam that that statement is common but wrong.
>> > > >> >>Give me some proof!
>> > > >> >>
>> > > >> >>Klas.
>> > > >> >>
>> > > >> >
>> > > >>
>> > >
>> > >m("sbcglobal.net/vwp2","//f2.pg.briefcase.yahoo.com/bc/rob_danielson");=">http:=
?.tok
>> > > >>
>> > =3DbcmKTRVBNxZgHObW&.dir=3D/Tests&.dnm=3DCompareMiniDiscMicPreNoise.m=
ov&.src=3Dbc
>> > > >> >
>> > > >> >Right-click on the paper-looking document and select, "Downloa=
d
>> > > >> >linked files as,.." option.
>> > > >> >
>> > > >> >I've uploaded the above 2.3 mb QuickTime movie that compares t=
he
>> > > >> >resultant noise from Rode Nt3 and Nt4 mics using a HiMD mic in=
put
>> > > >> >jack and the same mics routed through a Sound Devces MP-2 outb=
oard
>> > > >> >preamplifier into the HiMD's line input. The recordings were
>> > made at
>> > > >> >16/44.1; the QuickTime movie has an IMA:4 compressed sound tra=
ck so
>> > > >> >that more people can download it. Again, these tests are for q=
uiet
>> > > >> >location recording situations where high gain is more likely t=
o be
>> > > >> >used. The files are well saturated and loud, be sure to adjus=
t
>> > > >> >playback volume to a comfortable level
>> > > >> >
>> > > >> >To my ears, the NT3 presents a fairly close match between inte=
rnal
>> > > >> >and external preamp noise which suggests to me that an "effect=
ive
>> > > >> >self-noise" rating for the NH-900 HiMD recorder's mic pre _wit=
h
>> > this
>> > > >> >particular mic_ is in the ballpark of 16 dBA. [The self noise
>> > > >> >equivalent for the MP-2 (with some conservative assumption
>> > involved)
>> > > >> >is in the area of 5dBA, so its very unlikely to be adding nois=
e.]
>> > > >> >
>> > > >> >I say only for "this particular mic" because, as we found bef=
ore,
>> > > >> >sensitivity (output) and other factors come into play. You wil=
l
>> > note
>> > > >> >that I had to boost the playback level of the NT4's recording
>> > 14dB to
>> > > >> >match the playback level of the NT3's recording. Even though =
both
>> > > >> >mics have very close self noise specs (16dBA for the NT4 and 1=
7dBA
>> > > >> >for the NT3), the noise component in the NT-4's recording is a=
lso
>> > > >> >increased 14dB to match playback leve with the NT3's. The add=
ition
>> > > >> >of noise from the HiMD mic pre can be confirmed by looking at
>> > the NT4
>> > > >> >signal routed through the MP2 where we hear less noise than
>> > that from
>> > > >> >the recording where the NT4 is connected to the HiMD recorder'=
s mic
>> > > > > >pre.
> > > > >> >
>> > > >> >The NT3's recording (apparently taking advantage of effective
>> > higher
>> > > >> >output) exhibits about the same noise as the recording made
>> > when the
>> > > >> >NT3 routed through the MP2. This suggests to me that a HiMD mi=
c
>> > > >> >preamp is more likely to introduce significant noise when the
>> > record
>> > > >> >level is high and the mic does not have high output. This is
>> > > >> >consistent with our theory of why the Shure 183 performed wel=
l
>> > with
>> > > >> >22.5dBA noise in the prior test with its high sensitivity of 4=
2
>> > mv/Pa.
>> > > >> >
>> > > >> >So, there is no simple way to put MD mic preamp noise into a
>> > general
>> > > >> >"effective self noise" number because performance is the resul=
t of
>> > > >> >speciifc mic-preamp combinations. If you need further proof o=
f
>> > this
>> > > >> >phenomenon, according to Rode, the NT3 and the NT4 have equal
>> > > >> >sensitivity (12 mv/Pa). Their output impedance is also matche=
d at
>> > > >> >200 ohms.
>> > > >> >
>> > > >> >I tested the mics from the first test again and I feel the
>> > results of
>> > > >> >the first test are very reliable. That's is available as a sm=
all
>> > > >> >.mov now:
>> > > >> >
>> > > >> >http://www.micbooster.com/movies/TransMic&PreTestSor3_IMA.mov
>> > <http://www.micbooster.com/movies/TransMic&PreTestSor3_IMA.mov>
>> > > >> >
>> > > >> >People commented on the appreciable leap in quality that happe=
ned
>> > > >> >with the NT1A/Mp2 in the first test so I'm testing some higher=
end
>> > > >> >mic-pre combos. Rob D.
>> > > >> >
>> > > >> >
>> > > >> >
>> > > >> >
>> > > >> >
>> > > >> >
>> > > >> >
>> > > >> >"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:
>> > > >
>> > > >
>> > > >
>> > > >
>> > > >
>> > > >
>> > > >"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:
>> >
>> >
>> >
>> >
>> >
>> > "Microphones are not ears,
>> > Loudspeakers are not birds,
>> > A listening room is not nature."
>> > Klas Strandberg
>> >
>> >
>> > *Yahoo! Groups Links*
>> >
>> > * To visit your group on the web, go to:
>> > http://groups.yahoo.com/group/naturerecordists/
>> >
>> > * To unsubscribe from this group, send an email to:
>> >
>> >
>> <=3DUnsubscr=
ibe>
>> >
>> > * Your use of Yahoo! Groups is subject to the Yahoo! Terms of
>> > Service <http://docs.yahoo.com/info/terms/>.
>> >
>> >
>> >----------------------------------------------------------------------=
--
>> >
>> >No virus found in this incoming message.
>> >Checked by AVG Anti-Virus.
>> >Version: 7.0.308 / Virus Database: 266.11.8 - Release Date: 10/05/05
>> >
>> >
>>
>>
>>--
>>No virus found in this outgoing message.
>>Checked by AVG Anti-Virus.
>>Version: 7.0.308 / Virus Database: 266.11.8 - Release Date: 10/05/05
>>
>>
>>
>>
>>"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
________________________________________________________________________
________________________________________________________________________
|