Troubleshooting - Electro-Voice EVID 4.2 Installation Manual

14 en | Troubleshooting
4

Troubleshooting

Problem
No sound
Poor low-frequency
response
2023-07 | 04 | F.01U.177.642
Possible causes
Amplifier
Wiring
Speakers wired out-of-
polarity
Installation manual
EVID Surface-mount loudspeakers
Action
Connect a known working
test speaker to the amplifier
outputs. If there is no sound,
check that all electronics are
on, the signal routing is
correct, the source is active,
the volume is turned up, and
so on. Correct, repair or
replace as necessary. If there
is sound, the problem is in
the wiring.
Verify that you have
connected the correct wire
pairs to the amplifier. Play
something at low level
through the amplifier, for
example, from a CD player or
tuner.
Connect the test speaker in
parallel with the
malfunctioning line. If the
sound is gone or very weak,
the line has a short in it:
possibly a severe scrape,
pinch, or staple puncture. If
the sound level is normal, the
wire is open: possibly a cut
wire or missed connection.
Using the test speaker, move
down the line, test each
connection / junction until
you find the problem, and
correct it. Observe proper
polarity.
When two speakers are
connected out of polarity (out
of phase), the low
frequencies will cancel each
other acoustically. Carefully
observe the wire markings or
tracers on your speaker
wires. Verify that the amplifier
(+) terminal is connected to
the red speaker terminals and
Bosch Security Systems, LCC