Vonyx AP1200PA Manuel D'instructions page 4

TROUBLESHOOTING
One certain method of determining if a speaker is faulty is to substitute a speaker that is known to work correctly for
the suspected problem speaker. If the "normally correct speaker" is experiencing the same difficulties or problems
as the suspected problem speaker, use the information below to isolate the problem.
Problem
No output
Intermittent
Constant noise,
buzzing and/or
humming
Poor low-
frequency output
4
Possible cause Action
Cables Reseat all connectors
Substitute known good cables
Check solder joins
Inspect cable for damage
Inspect wire or connector for stray strand that may short
Poor connections While it is possible for a faulty speaker to exhibit intermittent output,
it's more likely that an output cable/connector is the problem. Check
the soldering on your connectors.
Faulty electronic Any constant noise originates in the amplifier, mixer, signal
processing, source device in the signal devices, or line-level wiring.
Check and correct system grounding as required. Chain check for
noisy sources or electronic components. Check wiring for shielding.
Improper polarity When two speakers in close proximity to each other are connected
out-of-polarity, they can partially cancel each other out, especially at
low frequencies. Check your speaker cables to be sure they are all
identically wired and connected. Check the balanced line signal
cables to be sure they are all correctly wired.