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Re: Which is better regarding gain and sensitivity?

Subject: Re: Which is better regarding gain and sensitivity?
From: madl74
Date: Fri Jun 12, 2015 11:33 am ((PDT))
> I've seen some people say it's better to use high sensitivity and low gai=
n, and other say low sensitivity and high gain, but never any explanation o=
f when or why. Does it vary depending on equipment or situation (or both)?=


Charles,

Sensitivity and gain are more or less the same thing in mics and amplifiers=

respectively. To minimise noise, you need to get the signal up as high as
practical as soon as you can, but without running into overloads, which set=
s
the maximum gain you can use.

The noise you can't do anything about is mic noise, and there really isn't=

much you can do to minimise that once you have got well into three $figures=
.
However, the criterion is to _maximise_ the mic hiss compared with the othe=
r
input preamp or mixer noises. In other words, don't add to what you can't
avoid.

It sounds odd, but it you can't hear mic hiss when its very quiet, such as=

with the pile of bedclothes test, you have got extra noise added. The
ultimate test is to listen for input noise with a "dummy mic" which is just=

a resistor of the same value as the mic impedance. (About 100 Ohms for a
powered mic)

David Brinicombe








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