On Sat, 9 Apr 2011 11:15:13 +0100, "Keith G"
wrote:


"Don Pearce" wrote in message
...
On Fri, 8 Apr 2011 16:59:20 +0100, "Keith G"
wrote:



It is a C03U multi-pattern and I reckon it's rather good, but the problem
with it is I get such a tiny signal from it connected direct to the
computer
and can't see any way of increasing it before recording. Should I be using
some sort of pre-amplification or is it better to jack up the levels in
the
recording - I'm having to increase the signal at least +6dB..??



The Samson mic has a maximum SPL of 136dB. Assuming the girls were
speaking at 80dB, that leaves 56dB to make up in software to achieve
full scale. More worrying perhaps, dividing 56 by six, that is 9 of
the 16 bits unused. So it is effectively using a 7-bit ADC. That makes
for a considerable noise floor.


Two things I would query: the girls are not loud and where does FS come into
it?


FS is the starting point - where you work back from in calculating
this stuff. The Samson spec says that FS is at 136dB. 16 bit noise is
96 dB below that (by definition, can't be any better). That means that
the mic has a hiss level equivalent to 40dB - my study is quieter than
that, so the hiss would be very intrusive.

I assumed the girls to be at 80dB to be kind really. That would give a
signal to noise ratio of 40dB. In all probability they are nearer
70dB, which would leave you with just a 30dB signal to noise ratio. A
quick measure of the file shows it to be somewhere between the two.



As for the Neumann, it is currently being ruined by that preamp. Spend
30 quid on a small Behringer mixer with its exemplary preamps and find
out what it is truly capable of.


I would gladly do that and post comparisons, what model do you have in mind?
Amazon is a preferred source and I would like USB connectivity to connect to
a computer that has no other 'audio in' apart from the usual front panel
'pink' microphone minijack socket.


Maybe a little pricey, but the 1204USB mixer comes in at about £160.
You can get a XENYX 802 for £40-50, but you need to feed it into a
sound card.

d