Fig. 5
3. Now bend the headband wire to fit your
head. Put the foam-block wire behind your
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 pre-
vents boom bounce when you move around.
5. Be sure that the thumbscrew is still loos-
ened a little. Move the boom in or out, and
left or right, to center the mic directly in
front of your lips.
The foam pop filter
should press firmly against the lips.
This
is necessary because the mic cancels
sounds that are not close to it. Also, it keeps
the boom from bouncing. Tighten the
thumbscrew and you’re done.
Once you’ve adjusted the headset, it should
remain in that position - no further adjust-
ments are needed. You can still swing the
mic up or down, away from your lips, if you
don’t want to be heard on the P.A. — or use
the mic on/off switch programmed for
“press off” operation.
After several hours of use, the foam pop
filter can become clogged with moisture,
giving a muffled sound. Periodically wash it
in mild detergent and water. The foam pop
filter is held in place by a removable ring.
Additional WS-6 pop filters can be ordered
from AKG’s Parts Department.
How to insert a battery in the CM311 A
belt pack
1. Access the battery by sliding open the
batterycover.
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
battery 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 automatically if phantom power fails.
After 85 hours of use, or if the sound is
distorted, 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.
*
Momentary on.
*
Momentary off (as supplied).
To change the switch operation, open the belt-
pack case by removing the three screws. Set
the switch as shown below:
The LED lights when the mic is on.
Architects’ and Engineers’ Specifications
The microphone shall be the AKG/Crown
Model CM311 A or equivalent. The
microphone shall be a head-worn, noise-
cancelling,
defective, return the complete product in its
original packaging to one of the addresses
d type of electret-condenser design.
microphone shall exhibit excellent off-
response and gain-before-feedback.
microphone shall have an adjustable
, adjustable boom with locking
l CM311 A shall include a battery belt
. In the CM311 A, a
42-inch,
y attached, two-conductor
d cable shall connect the micro-
e to the belt pack. The belt pack shall
e a 3-pin pro audio (XLR type) con-
l CM311 A shall be powered by a 9 V
ry in the belt pack, or by 18 to 48 V
m power. The belt pack shall have a
ry on/off switch, a programmable mic
switch, and a “Mic On” LED.
l open-circuit sensitivity shall be 4
5 mV/Pa. Maximum SPL shall be
dB SPL for 3% THD. Equivalent noise
be 27 dBA nominal. Frequency
shall be 50 Hz to 17,000 Hz with
off-axis response, over 20 dB
n at the
rear null. The AKG/Crown
rown professional microphones are
ranteed unconditionally against
from any cause for a period of
e years
from date of original purchase.
enclosed warranty sheet for additional
e microphone does not function prop-
, check that it is aimed correctly and is
d as described in this data sheet.
If
determine that the microphone product is
defective, return the complete product in its
original packaging to one of the addresses
. For further assistance or technical
the international helpdesk at
