ear. Then you can bend the earpieces to fit
snugly around your ears. The back of the
headband should fit firmly against the back
of your neck.
4. Next, adjust the foam pad snug against
your head or neck. To do this, bend the wire
that goes into the foam block. CAUTION!
Do not bend the boom itself – just the foam-
block wire. A snug fit of the foam pad
prevents boom bounce when you move
around.
5. Be sure that the thumbscrew is still loos-
ened a little. Position the mic to the side of
your mouth, about 1-inch (2.54 cm) in
front. To do this, move the boom in or out,
and left or right. Move the mic up or down
by bending the foam-block wire.
Changing the mic position changes the ratio
of lows to highs. Adjust the position for the
sound you prefer. If you hear breath pops,
move the mic farther to the side of your
mouth (Fig. 5). Tighten the thumbscrew.
Once you’ve adjusted the headset, it should
remain in that position – no further adjust-
ments are needed.
When using the mic for aerobics, you’ll
need to keep the cable in place. To do this,
attach the cable to the clothes clip (in-
cluded), and clip it to the back of your shirt.
As shown in Fig. 6, be sure that the cable
droops BELOW the clip. That way, sweat
drips off the cable instead of into the elec-
tronics.
Additional WS-7 foam pop filter and clothing
clips can be ordered from Crown’s Parts
Department.
CM-312A Schematic
How to insert a battery in the CM-312A belt
pack
1. Access the battery by sliding open the
battery cover.
2. Insert a fresh 9V alkaline battery (Mallory
Duracell MN9100 or equivalent) into the
battery tray. The battery cover shows the
correct polarity.
3. Replace the battery cover. To prolong bat-
tery life, turn off the battery switch when not in
use.
If you’re using phantom power, and the battery
switch is on, the battery will take over auto-
matically if phantom power fails.
After 85 hours of use, or if the sound is dis-
torted, it’s time to replace the battery.
How to program the mic on/off switch
The mic on/off switch can be programmed to
work in three ways:
* Push-on/push-off (as supplied).
* Momentary on (push to talk).
* Momentary off (cough button).
To change the switch operation, open the belt-
pack case by removing the three screws. Set
the switch as shown below:
TO XLR
MOM. ON
P.T.T.
PUSH ON/
PUSH OFF
MOM OFF
COUGH
Fig. 6
BT1
9V
S3
W5
W6
D3
VCC
W10
R2
SHIELD
WHT
RED
Q4
Q3
R6
R7
C4
R10
C5
R12
W3
R13
FB1
W4
R29
C6
VCC
C8
VCC
3
2
1
8
4
U3A
C10
R16
R19
R20
R24
R22
R25
C17
R14
C9
R15
GRN
WHT
SHIELD
C11
C15
C12
C14
W7
W8
W9
R27
R28
2
1
7
6 5
3
4
U4
Q5
C13
5
6
7
U3B
R17
R18
R21
R26
R23
9
10
U1D
11
12
U1E
1234
S2
D
5
CLK
Q
1
Q
2
S
6
R
4
U2A
Q1
R8
R9
Q2
R11
E1
C19
VCC
R4
R5
C7
14
7
3
2
1
8
U1A
5
4
U1B
7
6
U1C
R3
C3
D1
W2
S1
W1
C1
D4
R1
C2
C16
MICROPHONE CAPSULE
MICROPHONE ELECTRONICS
