Sorry to disagree with the various comments on this thread, but there
is a lot more than noise figures to consider in a recorder. For a
start, battery life, ease of use and reliability are more important in
use. Chasing the last dB of preamp noise would not be my priority but
see below.
For a start, the noise spectrums of the recorder, the microphones
(plural) and the recorder, and the ambience will be different, so the
effect of noise is not just additive in energy terms as dbs, but you
may hear all four sources. (as rumble, burble, mush, or hiss, etc) The
ideal is for the ambient noise to swamp all the system noises, but if
not, the irreducable noise should be the microphones' "excess noise".
You won't get better than that. Excess noise is precisely defined as
microphone noise in excess of the thermal noise of the air. "Self
noise" is a description which is rarely defined, if ever, in
comparison with the irreduceable thermal noise.
Microphones with a high output level should swamp mixer and recorder
noise by being 6dB or so higher in use whatever the subject matter.
The system I use is to record on a low cost Tascam DR-100 through a
high quality mixer (from eBay) and there are other options other than
just going for a recorder with a quoted low noise mic input. Fitting a
low noise preamp next to busy digital circuitry is what costs money to
get right in a recorder.
The response of the ear to low noise levels is very different to the
standard A-weighting, and the weighting used for noise measuremnts is
"468" in various incarnations because that is what matches the ear. It
is not used by "domestic" device manufacturers because it has a 12dB
lift which makes the noise figures look bad to the ignorant.
My general advice, as ever, is if possible to listen to the
alternatives and forget the theory in the final resort. My Tascam
DR-100 mic input preamps are noisier than my MKH 416's, so from the
figures given in this thread, many other recorders will be within a dB
or so of this poor result. Hence my splashing out on a good mixer.
David
David Brinicombe
North Devon, UK
Cogito cogito ergo cogito sum - Ambrose Bierce
|