naturerecordists
[Top] [All Lists]

Re: Re: PIP Mics Booster Pres Test

Subject: Re: Re: PIP Mics Booster Pres Test
From: Rob Danielson <>
Date: Fri, 15 Apr 2005 18:19:39 -0500
At 11:41 AM -0400 4/15/05, Steve Pelikan wrote:
>I'll try, though I imagine there'll be some debate about the
>interpretation of the results.
>
>Rob recorded a ticking clock and egg timer using various microphones,
>preamp gain settings, and in several cases, supplementary amps between
>microphone and recorder's preamp.
>The recordings were made using a MD recorder then transfered to a
>computer (I take it) and their overall sound levels were adjusted so
>that sound levels in the recordings are all about the same.
>
>In one comparison that I found informative, the same microphones (Rode
>NT4 XY) were used with different preamp gain settings (18 and 28,
>whatever that means) then received +24dB and +20dB in "post". The noise
>levels in these two recordings sound about the same to my (admitedly
>inexperienced  --- plus I listened on cheapo speakers connected to a PC)
>ears. I take this as evidence in favor of your (Klas's) assertion that
>the preamp noise isn't as much of a problem (isn't heard as much) as the
>noise from the microhpone.

I've been thinking about the MD mic pre noise factor too. This below
_may_ be a correct deduction:

If the noise in the tests is primarily from mic self noise AND the
manufacturers spcecifcations are close to correct, it would follow
that the NT4 would have the least noise and the 183's and the MS957
would be very close to the same. This is not what I'm hearing.

If this tests are inconsistent the assertion that the noise is from
mic self noise, then at least two of the factory specs must be off.
I base this on my perception that the NT-4 (18dBA self noise )
recording does not have less noise than the other two mics and that
the MS957 (25dBA) and  183 (23dBA) do not have very similar noise.

If the MD pre is introducing noise, then the mics with less output
(sensitivity) should produce recordings with more noise. This seems
to be fully consistent with the factory specs for  all three mics.

My best guess at this point is that the MD mic pre is adding a
consistent amount of noise between the "18" and "28" settings. This
is totally new suggestion but it could be tested.

Note also that all of the MD mic pre tests had to be boosted a lot in
order to match the saturation of the MP2/NT1A combination.

Don't you think the FELS is helping the MS957's performance and a bit
also for the NT-4?


>
>In some recordings an additional +20 dB "booster" was used. I didn't
>notice a lot of improvement as a result.
>
>The quietest of all the samples was from Rode NT1A microphones, an MP2
>preamp and MD preamp gain of 28. Again, I conclude that the MD preamp
>isn't a problem but that the noise is primarily from microphones. (I
>don't know but I suspect that these NT1A's are more expensive/ higher
>end than most of the other microphones in this comparison. I certainly
>think this is the kind of recording I'd like to be able to make!)

The MP2 is $700 and NT1A Rodes Mics are $200 each. I wish I had been
able to use the NT4 through the MP2 to get a pre/pre comparison. I
can do this with 2 Rode NT-3's and will try to add an addendum test.
Rob D


>
>I hope this helps a little and will try to go into more detail if people
>want me to. I'm also looking forward to hearing other people's thoughts
>about this study and more than willing to agree that I'm just a novice
>at this sort of thing!
>
>I join others in thanking Rob for his efforts. The results were nicely
>presented and I feel he's done us all a great service by making this
>study available.
>
>Cheers!
>
>Steve P
>
>
>Klas Strandberg wrote:
>
>>For us antique modem users, can anyone tell in words what this test was a=
ll
>>about and what the results were?
>>
>>Klas.
>>
>>At 15:47 2005-04-15, you wrote:
>>
>>  >Once again, Rob Danielson treats us to truth:
>>  >
>>  > > http://www.uwm.edu/~type/Mic%20Preamps/Mic&PreTransparencyTests/med=
ia/
>><http://www.uwm.edu/~type/Mic%20Preamps/Mic&PreTransparencyTests/media/>
>>  > > TransMic&PreTestsSor3_01.mov
>  > >
>>  >And again we see that TRUTH HURTS! This will take some serious
>  > >pondering...
>>  >
>>  >Curt Olson
>  > >
>  > >

--
Rob Danielson
Film Department
University of Wisconsin-Milwaukee


________________________________________________________________________
________________________________________________________________________

<Prev in Thread] Current Thread [Next in Thread>
Admin

The University of NSW School of Computer and Engineering takes no responsibility for the contents of this archive. It is purely a compilation of material sent by many people to the naturerecordists mailing list. It has not been checked for accuracy nor its content verified in any way. If you wish to get material removed from the archive or have other queries about the archive e-mail Andrew Taylor at this address: andrewt@cse.unsw.EDU.AU