Crown CM-700 User Manual

Mic Memo

Mic Memo

Crown’s Quarterly Microphone Newsletter

Fall 2002 Bruce Bartlett, Editor

CM-700 Chosen for “Dream” Studios

if the room acoustics are very
dead. Otherwise the mics pick
up a lot of room reverb which
muddies the sound. Also, ceil­ing mics work poorly for sound
reinforcement. The distance
from mic to source is just too
great to allow much gain-before-

CM-700

In the July, 2002 issue of Elec­tronic Musician, in the article

"Build a Personal Studio on Any
Budget," the Crown CM-700
cardioid condenser microphone
was chosen to be part of three
proposed "dream" studios.

Those studios were the $6000
portable digital studio, the
$15,000 Windows studio, and
the $30,000 studio without com­puter.

Ceiling-Mounted Conference Mics

Mics are commonly used in con­ference rooms for recording,
teleconferencing, and sound
reinforcement. Many customers
do not want to see the micro­phones, so they specify ceiling­mounted mics. In this case,
appearance is a higher value
than sonic performance.

Ceiling-mounted mics are feasi­ble for audio recording, but only

feedback. If at all possible, use
table-mounted mics for best
gain and clearest sound.

If you want to use an omni ceil­ing-mounted mic, try a Crown
PZM-11 in an electrical box. It
costs little, and its high frequen­cies are boosted for extra clarity.

For less reverb pickup, try four
Crown MB-4 mics on the ceiling
angled 90 degrees from each
other. Feed the four XLR out­puts to an automatic mixer.
Recommended settings on the
mixer are: release time very
long, and automatic gain control
on. Again, this setup is not rec­ommended for sound reinforce­ment.

Crown MB-4 boundary mic

CM-700 for Stage Vocals

Although the CM-700 was not
designed to be a stage-vocal
mic, it can be made to work
quite well in that application.
Singer/guitarist Bob Lichty used
the CM-700 for vocal pickup at a
recent concert. He had this to
say about its use:

"I used the double low-cut filter
on the CM-700 for vocals. For
guitar, I left the low-cut switch
flat and rolled out a bit of the
lows at the board. I learned how
to "mask" my p's and t's with
singing technique, so they are
rarely an issue for me. I love the
sound of the 700, and even my
wife can't believe how different I
sound 'all miked up' versus just
singing at home in the bed­room."

What’s Inside

• CM-700 Chosen for "Dream"
Studios

• Ceiling-mounted Conference
Mics

• CM-700 for Stage Vocals

• Harp Miking

• Lavalier Mic EQ

• Miking an Electronic Organ

• PZM Piano Miking

• CM-311AE Fan

• What’s a PXT?

For more information, call 800-342-6939

1

Mic

Memo

Harp Miking

Here's an unusal miking applica­tion for sound reinforcement.
How do you mike a folk harp? It
is a small instrument about 4
feet tall.

Try a Crown GLM-200, a mini
mic with a hypercardioid polar
pattern.

GLM-200 hypercardioid mic

Mount the mic inside the harp
near one of the sound holes.
You can attach the mic by taping
its cable to the harp, or by using
the supplied GLM-UM Universal
Mount.

the handheld mics. What sort of
equalization is needed to do
this?

First, note that nearly all hand­held vocal mics are directional,
so they have proximity effect
(bass boost when used close to
the mouth). Omnidirectional
lavalier mics have no proximity
effect. To simulate that, you
might boost 4 to 6 dB around
100 Hz. (Be careful with feed­back whenever you apply an EQ
boost.)

Lavalier mics have a built-in
high end rise to compensate for
being off axis to the mouth. You
might need to do more high-fre­quency tweaking by ear. Also,
most lavs exhibit a peak around
630 Hz (about 3 or 4 dB, less
than 1 octave wide) due to body
diffraction and chest reso­nance. Cutting that frequency
by the same amount can
remove the "puffy" sounding
midrange peak, making the lav
sound more like the handheld
mic.

• Ground loops can create hum.

• You might be held liable for
messing with the organ electron­ics.

• The organ technician might
remove the connection.

• Many organs don't have a
composite or full-range feed,
meaning that the electrical sig­nals to the various loudspeaker
drivers are bandpassed. If you
tap off a loudspeaker you may
not get the full spectrum of the
organ. If you combine the band­passed outputs to get a full­range feed, you might be held
liable for tampering.

• A lightning strike that gets into
the organ electronics might get
into the audio system, or vice­versa.

Using a mic instead of a direct
connection avoids all the prob­lems mentioned above. A close­up omni mic, strategically
placed, will pick up very little of
the room and other sounds. We
suggest the Crown GLM-100
mini omni mic. It's very small
and picks up down to 20 Hz.

Ask the harpist to play as you
monitor the sound. Adjust the
angle and position of the GLM­200 until you hear a tonal bal­ance you like.

Lavalier Mic EQ

Many theater sound systems
employ handheld mics for sing­ers and lavalier (clip-on) mics for
actors. Sometimes the sound
operator is asked to make the
lavalier mics sound the same as

For more information, call 800-342-6939

2

Miking an Electric Organ

Some houses of worship feature
an electronic organ. Often it's
necessary to feed the sound of
this organ into the sound sys­tem. It seems reasonable to find
a line-level signal within the
electronics and connect to it, or
connect to the organ’s speaker
terminals. Unfortunately, these
connections can cause several
problems:

Note: This close mic placement
is for sound reinforcement, not
recording. If you want to record
the electronic organ, place a pair
of mics several feet away (about
12 to 20 feet) to pick up the
room reverb as well as the
sound of the organ.

The GLM-100 looks the same
as the GLM-200 pictured on this
page.

Thanks to Pat Brown of Syn Aud
Con for this idea.