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 both
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 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:
>
>
>
>
>
>
>"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
________________________________________________________________________
________________________________________________________________________
|