At 23:55 2005-05-04, you wrote:
>I went down to fix dinner and realized that my logic is wrong about
>being able to deduce any Mic Pre noise figure from the test. Sorry.
>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 noise
>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 would
>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. Have 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 referring 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?.tok","//f2.pg.briefcase.yahoo.com/bc/rob_danielson");">http:
> =bcmKTRVBNxZgHObW&.dir=/Tests&.dnm=CompareMiniDiscMicPreNoise.mov&.src=bc
> >
> >Right-click on the paper-looking document and select, "Download
> >linked files as,.." option.
> >
> >I've uploaded the above 2.3 mb QuickTime movie that compares the
> >resultant noise from Rode Nt3 and Nt4 mics using a HiMD mic input
> >jack and the same mics routed through a Sound Devces MP-2 outboard
> >preamplifier into the HiMD's line input. The recordings were made at
> >16/44.1; the QuickTime movie has an IMA:4 compressed sound track so
> >that more people can download it. Again, these tests are for quiet
> >location recording situations where high gain is more likely to be
> >used. The files are well saturated and loud, be sure to adjust
> >playback volume to a comfortable level
> >
> >To my ears, the NT3 presents a fairly close match between internal
> >and external preamp noise which suggests to me that an "effective
> >self-noise" rating for the NH-900 HiMD recorder's mic pre _with 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 noise.]
> >
> >I say only for "this particular mic" because, as we found before,
> >sensitivity (output) and other factors come into play. You will 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 17dBA
> >for the NT3), the noise component in the NT-4's recording is also
> >increased 14dB to match playback leve with the NT3's. The addition
> >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 mic
> >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 well with
> >22.5dBA noise in the prior test with its high sensitivity of 42 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 result of
> >speciifc mic-preamp combinations. If you need further proof of this
> >phenomenon, according to Rode, the NT3 and the NT4 have equal
> >sensitivity (12 mv/Pa). Their output impedance is also matched 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 small
> >.mov now:
> >
> >http://www.micbooster.com/movies/TransMic&PreTestSor3_IMA.mov
> >
> >People commented on the appreciable leap in quality that happened
> >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:
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