I'd like to try to clarify something for myself and any other dummies like me
who dont quite get this. I sometime read posts or articles where the writer
says that the noise figure of a particular peice of gear (for instance, a mic)
is less than something else (perhaps the noise of the room or another peice of
gear or whatever).
Someone might say (and they have) that the noise figure of a particular mic is
lower than the ambient noise in the room and therefore the mic noise is a
non-issue. I take this to mean that they are saying that the noise in the room
sort of swallows up the mic's self noise and nullifies (masks?) it.
Lets say for example that a mic has 22dBA self noise figure and that the room
has 40 dBA ambient noise. (excuse me if I am quantifying these figures wrongly)
I get the impression that the combination of these two noises added together
would not be 62dBA as would seem logical to me. If the noises did add together
in that way then I dont believe people would say not to worry about a mic's
self noise because the room is so much noisier. Instead they would be saying
that the mic's self noise is just as important in the 40dBA room as it would be
if the room noise was 20dBA.

So, I hope I'm getting the context for this question across, even in my clumsy
way. If I understood enough to ask it right I'd probably know the answer.

So, does the noise of different links in the chain combine in a linearly
additive way or is it more complicated than that? For the purpose of this
question can we set aside the issue of how much noise is actually problematic
or audible and can we just stick to the theoretical way in which noise combines
with other noise, all other things being equal?

Garth~


"I think the fact that music can come up a wire is a miracle."
Ed Cherney