David Satz
July 1st 03, 12:50 AM
Justin Smith wrote:
> I just have a quick question: Generally speaking, to avoid leakage of
> other sounds into a particular mic (say when close micing toms),
> should one try to move the mic as far--distance wise--away from the
> unwanted sound, or try to get as far_ off-axis_ as possible,
> regardless of distance?
I'm forced to agree with David Butler, and maybe even to say that it's
worse than what he says: Even the very best cardioids are not much help.
Cardioid just isn't a strongly directional pattern to begin with, and no
actual cardioid is anywhere near consistent at all frequencies. They all
become less directional at low frequencies and they all get goofy in
various ways at high frequencies, too--peaks and dips at various angles
of sound incidence are par for the course.
So with drum sets, where there's sound across such a wide range of
frequencies, you can't filter very much out by aiming a cardioid away
from the unwanted source. Certainly not a high-hat. You can see this
if you look carefully at polar response diagrams that have been plotted
at various frequencies. The better microphone makers offer such graphs;
they're not necessarily easy to read, but it's well worth the effort.
And I'm also forced to agree with Mr. Butler that well-made supercardioids
will have less of this problem than any cardioid. Their polar response is
more nearly constant across the audio frequency range, as a rule, and their
nulls have notably greater cancellation (in dB) than the null of a cardioid.
> I just have a quick question: Generally speaking, to avoid leakage of
> other sounds into a particular mic (say when close micing toms),
> should one try to move the mic as far--distance wise--away from the
> unwanted sound, or try to get as far_ off-axis_ as possible,
> regardless of distance?
I'm forced to agree with David Butler, and maybe even to say that it's
worse than what he says: Even the very best cardioids are not much help.
Cardioid just isn't a strongly directional pattern to begin with, and no
actual cardioid is anywhere near consistent at all frequencies. They all
become less directional at low frequencies and they all get goofy in
various ways at high frequencies, too--peaks and dips at various angles
of sound incidence are par for the course.
So with drum sets, where there's sound across such a wide range of
frequencies, you can't filter very much out by aiming a cardioid away
from the unwanted source. Certainly not a high-hat. You can see this
if you look carefully at polar response diagrams that have been plotted
at various frequencies. The better microphone makers offer such graphs;
they're not necessarily easy to read, but it's well worth the effort.
And I'm also forced to agree with Mr. Butler that well-made supercardioids
will have less of this problem than any cardioid. Their polar response is
more nearly constant across the audio frequency range, as a rule, and their
nulls have notably greater cancellation (in dB) than the null of a cardioid.