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Re: modified ambient recording setup AT 3032

Subject: Re: modified ambient recording setup AT 3032
From: "Rob Danielson" danielson_rob
Date: Sat Dec 1, 2007 10:56 pm ((PST))
Hi Steve--
Your sound file might help in the discernment of significant
differences. Looking at a sonogram I made, one can note some,
fairly-pronounced bands: T32-diff_Sonogram.gif"  in the group files
or, after you have logged in:  http://snipurl.com/1uhzp

As two capsules cannot occupy the exact, same location in space, some
of the difference can probably be attributed to room acoustics--
although most of these frequencies should reside under 2,000 Hz. Some
of the horizontal bands formed above 3K might be audible. When you
listen to both mics can you hear some concentrations of noise at 3K,
10K, and 15K Hz? Can you hear greater 192-440 Hz "warmth" in one mic?
Rob D.



At 12:21 AM +0000 12/2/07, Steve Cox wrote:
>I am interested in hearing what other experiences are out there in
>regards to getting close
>to a matched pair of the 3032's. Interesting thing about these mics,
>there doesn't appear
>to be an serial number on them. I was hoping that AT would offer
>matched pairs but I
>don't know how they would keep track of them.
>
>I followed Scott's suggestions and recorded a small bit of pink
>noise with the mics almost
>touching, inverted the right channel and saved the mono file. It's
>in the "Files" area and
>called T32-diff.wav. If it was a dry day I would have tried Rob's
>method as well. I also do
>not have 3 or 4 good headphones. I'm lucky to have one.
>
>I recorded with my 722 @ 24/96. There seems to be a fair amount of
>difference between
>them but other than noticing the glaring small band at 16K I really
>don't know how to
>evaluate these two as a pair. I am now going to test my matched pair
>of NT1-A's using the
>same method with the same gain.
>
>I know there are people on this list that know far more about this
>stuff than I do. Thanks,
>in advance, for any and all help/advice.
>
>Steve Cox
>
>--- In
><naturerecordists%40yahoogroups.com>=
m,
>Scott Fraser <> wrote:
>>
>>  <<1) how would i go about testing each mic to make sure they match? i
>>  was planning on pumping out some white noise and recording each one
>>  from the same perspective. then maybe checking it on a graphic eq
>>  program in protools? is there anything else i can do to test their
>>  response?>>
>>
>>  Pink noise is better & more appropriate for this sort of broadband
>>  frequency response testing, since it contains equal energy per
>>  octave. Mount the mics as physically close together as possible, &
>>  record the pink noise. Play back the stereo file in mono with the
>>  polarity inverted on one channel only. Perfectly matched mics should
>>  perfectly cancel, except for the very highest frequencies, where the
>>  slightly offset physical location means a slight phase offset.
>>  Everything you hear which isn't cancelled is the frequency response
>>  difference between the two mics.
>>
>  > Scott Fraser


--







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