Eric Benjamin wrote:
> Making the generous assumption that the Quadmic noise is -129 dBV, it's 1=
0 dB quieter than the microphone. That's good, but maybe not good enough. =
If you rms those two noise sources together that gives you a 2.4 dB increa=
se in noise relative to the microphone with a 'perfect' preamplifier. OK, =
Message: 2.
Subject: 4 dB isn't a substantial hit in performance. But you pay a lot for
those=
quiet microphones!
Hmmmm... Here is something wrong! If the preamp noise voltage is 10 dB lowe=
r than the noise voltage of the microphone, then one would get an overall i=
ncrease of the noise floor by 0.4 dB only (see http://www.rane.com/note148.=
html or http://www.avisoft.com/tutorial_mic_recorder.htm). I guess that thi=
s slight increase is inaudible and therefore irrelevant.
> I have enjoyed using the Earthworks ZDT1024 in the past, and it has input=
noise of -143 dBV at a gain of 60 dB, 14 dB better than the Quadmic. On t=
he other hand, it's $3200 for four channels as opposed to $550, and that's =
a huge price penalty.
I'm afraid that a preamp noise figure of -143 dBV does not provide a signif=
icant advantage in conjunction with any real microphone under real-world co=
nditions...
Regards,
Raimund
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