[LAU] USB audio interface support?

Ng Oon-Ee ngoonee at gmail.com
Thu Nov 26 04:55:17 EST 2009

On Thu, 2009-11-26 at 10:46 +0100, Lorenzo wrote:
> Hi,
> > 1) How much gain is needed by the Shure SM57 for comfortable recording
> > with a low noise floor?
> > 2) Whether the M-Audio Fast Track Pro, Tascam US-144, Alesis IO|2 or
> > Edirol UA-4FX are able to provide pre-amping with that much gain?
> >   
> I'm not sure I understand correctly the question...
> As for 'noise floor' much for example depends on the input signal, 
> environment etc. or are you talking about the intrinsic 'noisiness' of 
> pre-amps on the cited devices?. Maybe if you explain the situation/setup 
> one could have a clearer picture.
> Anyway, because the SM57 is a dynamic microphone you should be ok with 
> virtually any decent mic preamp: at an extreme limit you could probably 
> even plug it into your computer's "mic in" (but then of course might as 
> well use a 10$ skype microphone or something :) ).
> Lorenzo.
Thanks Lorenzo, I'll try to give a clearer picture.

There's multiple reports (see my thread
http://forums.m-audio.com/showthread.php?t=14610) concerning SM57 not
being loud enough with the M-Audio Fast Track Pro. Basically the
complaint is that the built-in pre-amp does not provide enough gain,
such that increasing the jack gain and/or software gain gives a
relatively noisy signal.

One of the engineers at M-Audio, in the thread I mentioned, said that
the M-Audio gives up to 40 dB of pre-amp gain, while the SM57 needs
about 50 dB to operate optimally. In other words, it works, but it'll be
soft, and soft enough that if you try to record quite plucking your
recording will be noisy once software-amplified.

And I tried plugging the SM57 to my laptop's 'mic in' but of course the
result sucked, way too low SNR =). That's just to be expected of course,
without any pre-amping at all.

P.S. - I probably don't understand the proper use of 'noise floor'. For
me, its the level of noise in a recording at a particular gain, at
higher gains the noise floor is raised obviously (following this
definition) therefore we should avoid raising gain unnecessarily. This
refers to electrical noise, not background noise.

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