LRAD
1950XL
GENASYS INC.
Manual Part No.:114931-00 rev. B
23
About microphone feedback:
Microphone feedback is caused when the microphone picks up output from the LRAD, causing a
loud harmonic hum through the device. Placing the microphone directly in the sound
projection path of the LRAD and keying the
‘
Push to Talk
’
Button would result in the worst-case
feedback scenario. This is because the sound being produced by the LRAD is being fed back
into itself, causing a reverberation that amplifies certain frequencies, resulting in a loud screech
or squeal from the device. The LRAD’s focused sound pattern al
lows for use of the microphone
when standing behind the LRAD, where the sound from the LRAD is greatly reduced, however,
there are some operational conditions that will inevitably cause feedback.
How to Limit Feedback:
•
Adjust the volume: Lower the volume level of the LRAD until feedback is negated.
•
Avoid reflections: If the output from the LRAD is bouncing off of a solid object such as a
building and making its way back to the microphone, feedback will occur. Try
repositioning the LRAD or the microphone to prevent the
LRAD’s output
from feeding
back through the microphone.
•
Maintain your distance: The farther away the microphone is from the LRAD, the less
feedback you will experience. Only use the microphone behind the LRAD and keep it
out of the main acoustic beam.
•
Shield the microphone: If you can shield the microphone operator from the LRAD
’s
acoustic output, the microphone feedback will be reduced. Stand behind a physical
barrier or inside a guard house or ship’s bridge. You may also use your
free hand to
cover the area surrounding the microphone to attempt to limit feedback.
•
Use the push to talk button to your advantage: Releasing the PTT button on the
microphone immediately after speaking will limit feedback. Leaving the PTT button
depressed will allow feedback to go through
In the event that a maximum power broadcast of a verbally spoken message is needed, the
handheld microphone can be used to record, store and playback a message of approximately
one minute in duration.
To record and play back using the recording microphone, reference the following figure and
take the following steps:
•
Press and hold the Record button (2).
•
While holding the Record button, press and hold the Play button (3).
•
The recording/playback indicator LED(4) will light green while the unit is
recording.
•
The unit will record as long as the Record and Play buttons are held down and as
long as there is storage space in the internal memory.
•
Speak your message into the microphone element (5) and release the Record
and Play buttons when done speaking.
