Posted by: "cfmspencer"
> in comparing the likely usefulness of mics for
> quiet ambient nature recordings, I've been
> dividing the sensitivity spec figure by the
> noise spec figure and ranking mics relatively
> based on the result.
>
> by this method, a Sanken mic with 20db noise
> and 50mV output would rank higher than a Sennheiser
> with only 12 db noise and 25mV.
>
> does this seem a reasonable way to compare, or is
> lower noise ultimately more important than higher
> output?
The two specs are not even the same measure. So your method makes no
sense. Compare them separately.
The way I think of it is that the self noise figure tells me something
about how quiet a site the mic can record in. Note that even if
recording loud calls this can be important if the background sound
levels between the calls are low. Self noise is the floor of the sounds
in your recording imposed by the mic. It's more or less independent of
the sensitivity, though through the gain of the mic pre the two interact
somewhat. Compare it to the noise floor of your site.
Sensitivity probably relates more to the reach of a mic. How much
distance away it can be from the caller and still make a good recording.
Many mics are designed for work on fairly loud sounds right at the mic.
We hunt for the few that are designed for more distant pickup, and then
push that well beyond their design distance. It does also somewhat
relate to the self noise, in that greater sensitivity may seemingly give
less influence to self noise. Sensitivity more is a measure of how much
you can raise the calls above the mic's self noise floor.
> yes, I know, it's not all about specs, and that
> I will need to work with mics to truly determine
> what works best for me.
Indeed, too much emphasis is given to the numbers and not enough to
field experience.
Indeed, the best specs in the world don't do you much good if it's the
wrong mic for the job. Or if it does not tolerate the outdoor
environment well. Or if it's hypersensitive to handling or wind. These
and more are all things you find out by getting out and recording the
subjects that interest you.
Mic choice is a personal one. We are all somewhat artists communicating
our personal concept of the soundfields we hear. The mics are a critical
tool for that.
Walt
|