8
Adjusting the Audio Levels
This interface has an integral BEAM (Bavis Enhanced Audio Module) module which is a very
powerful voice processing system. This system has both echo cancellation and background noise
suppression.
There are adjustments for both incoming and outgoing audio levels inside the interface. A small
screwdriver is
included,
to make this adjustment. The adjusters are ¾ turn.
The adjustment procedure is to have someone in a running vehicle in the drive-thru talking to the
technician on the telephone. With the outgoing audio adjusted down, in small increments, turn
the incoming audio level down. Normally there will not be any appreciable reduction in the
sound level at the handset coming from the drive-thru lane. The AGC (automatic gain system)
of the telephone system is automatically reducing the signal to an acceptable level. When the
incoming sound level does decrease, increase the level slightly until the sound comes back up to
the normal level. This setting will give the echo cancellation system maximum range. Then
adjust the outgoing level for usable audio, not excessively loud. Excessive outgoing audio levels
may cause distortion in the incoming audio.
In the interface, there are four (4) configurations available. Selecting the configuration is
performed by moving the jumpers on the headers marked as JP1 & JP2, (See the BEAM Jumper
Configurations illustration). To determine which configuration is currently programmed in,
without opening the enclosure, watch the flashes of the LED near the Intercom Connection port.
Configuration 1
: One flash then pause. Each jumper is on only one pin of the JP1 and JP2
headers.
Bypass – Only used for Factory calibration. No alteration of the audio signal.
Configuration 2
: Two flashes then pause. JP1 jumper is on both pins and JP2 jumper is on only
one pin.
Normal – Echo Cancellation & Noise reduction.
Configuration 3
: Three flashes then pause. JP1 jumper is on only one pin and JP2 jumper is on
both pins.
Extra Magic – Echo Cancellation, Noise reduction, & Speech boost.
Configuration 4
: Four flashes and pause. JP1 jumper is on both pins and JP2 jumper is on both
pins.
Reduced Outgoing Audio – There is Echo cancellation and noise reduction with the outgoing
audio volume level reduced.
