> Set sense to Low and turn on to Record Pause; adjust gain on iRig.
Max,
Theory says that you should use a higher gain in the input stage
provided it doesn't overload. You will have noise from the input stage
whatever the level you set later, and for anything that follows,
hopefully the later noise is swamped by the mic and input stage noise.
However, theory should be backed up my experimentation, so it is worth
doing a "family" of measurements. High frequency and low frequency
input noises can also give different results. What is essentiul is to
record a reference level from an acoustic input at your test settings
to have something to compare the noise levels against. Find a sound
source with a good range of frequencies that is repeatable like a food
mixer in a kitchen and do the measurements at varying settings as you
have been doing. Now you have something to compare your noise levels
against.
What makes noise levels difficult to compare is when their frequency
plot varies. Hiss is normally the most distracting, so recording
everything with a set bass cut can help. With a power spectrum, you
can usually see bands of noise as well. Keep notes on every
measurement. You can then reference the noises against the acousitc
levels for each
of your settings.
Give yourself a good bit of leeway by recording low. You should find
that digital recording noise s very low, but check that as well.
I do hiss measurements with the mic under a pile of bedclothes. You
still get rumble and a lot of domestic noises, but the acoustic hiss
level should be low.
You should also be able to recognise different types of noise. I wrote
the other day about the fundamental noise which you should be able to
hear on a mic with a good noise spec. Once you latch on to this
particular noise, the goal is to hear it on every recording. :-)
David
David Brinicombe
North Devon, UK
Cogito cogito ergo cogito sum - Ambrose Bierce
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