Klarinet Archive - Posting 001181.txt from 1998/12

From: "Benjamin A. Maas" <bmaas@-----.net>
Subj: Re: [kl] Recording Clarinet
Date: Wed, 30 Dec 1998 13:26:18 -0500

>Further information to my earlier post.
>I'm using Logic Audio software(and many plugins) with PII 300, 128MB
memory,
>Gina (Event) audio card, Mackie mixing board, and one Audio Technica
AT4033a
>cardioid capacitor mic.
>The room is approx. 10ft. x 12 ft. and is rather dead with carpet and
>curtains.(spare bedroom)
>I'm wanting to record solo clarinet and clarinet with piano.

OK.... This helps a lot. The computer setup is great, no problems there.
The microphone choice is a good starters microphone--great value for the
price, and Mackie boards are some of the best bang for the buck out there.

The first thing I am going to recommend is to get a second microphone (same
kind). With one cardioid microphone, you are only going to be able to
record in mono. Stereo pairs of microphones must be matched, i.e.. you
shouldn't use one Audio Technica microphone and one Neumann. They have
different sounds and that wouldn't make a good stereo image/sound.

With two cardioid microphones, there are two kinds of stereo microphone
technique you can use. One is a coincident pair and one is near-coincident.
These terms generally refer to the ability to keep everything in phase
(signals reaching the capsules at the same time). An X-Y pattern has the
two microphone capsules right over each other facing the sound source at a
90 degree angle. This gives the two patterns a fair amount of overlap
giving you a smaller, tighter stereo image. Another technique is the ORTF
method. Here the capsules are about 7" apart (tip of thumb to tip of pinky
stretched out) and angled at 110 degrees. This induces a *little* bit of
phasing problems as the capsules are not right next to each other. Some
sound will hit one before the other. The wider angle will also give you a
bit bigger stereo image.

No one technique is always going to be right. It depends on the room for
which will give you a better sound.
As for the board: Plug in and of course use phantom power for these mics...
Adjust the gain so most sound is going to be at about -12 on your digital
meters with peaks at -2 or so. Remember, with digital recording, 0 is a
brick wall. If you go above it, you clip and that sounds like total digital
distortion (NOT PRETTY!!!). It is better to keep the levels too low than
too high.

I tend to not use EQ on the board, especially on the Mackies. If you have a
fast computer with plugins (you do), take care of EQ/reverb, etc... in post
production... after you record. Always record clean. Also on the Mackie,
if any gain knob is turned up to high, it increases the noise (hiss) in the
recording. To set gain, set your master and each channel at unity (zero)
and adjust the trim to get levels about right. This will give you plenty of
room for adjustment.

Last bit--panning. The pan pot is what routes the sound out either the
right or left channel of the mixing board. When doing 2 microphone stuff, I
generally pan hard left and hard right.

To place the microphones, when I go into a room I have never been in, I keep
a couple of acoustical things in mind. The first is obvious: which
direction are the performers pointing? If you are using a grand piano, look
at the angle that the lid makes, this area is where the most direct sound
will be. When it comes to distance, I think about the three fields of
reverberation: Near; Middle; and Far. In the near field you are going to
have lots of early reflections and direct sound, i.e. not much "reverb." In
the far field you get the opposite. Lots of reflections, but not much
direct. The trick is to balance these two (set up in the mid field) as
neither will sound particularly good on a recording. The location of these
fields change from room to room. If the room is dead, the near field will
be much bigger and therefore you can set up farther away and still get a
good sound. In a very reverberant room (i.e., a church or gymnasium), your
near field will be tiny if not almost non existent, so therefore the
microphones will need to be much closer to get a good sound.

Last thing. You didn't mention any sort of a DAT recorder, so I will assume
that you are going to record straight to hard disk. When doing this, take
special care to keep plenty of drive space and keep your drives fully
optimized. 16 bit 44.1 kHz sampling rate (that used on CDs) takes up 10
megs of space per minute. When you do a lot of recording or editing, you
will get massive fragmentation. Use a program like Norton Utilities to keep
your disks in good shape.

Good luck. If anybody has questions, write to me and I will do my best to
help (either on or off the list). If you want to look at some good books on
recording, check out Modern Recording Techniques by Huber and Runstein and
Stereo microphone techniques by Bruce Bartlet. Both are easy to get and
good books.

--Ben

Benjamin Maas
Clarinetist and Digital Recording Engineer
Student, University of Southern California
Executive Director, Digital Renaissance Consort
bmaas@-----.net
bmaas@-----.edu

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