Harman-Kardon 223/223XL - Manual (Page 12)

2-Way, 3-Way
4-Way Crossovers
223/223XL - 234/234XL
• Check that a clean signal is being fed to the crossover.
• Confirm that the input wiring is correct.
• Check that the grounds of the audio signal path and the chassis and
power line of all units in the system are connected.
If you suspect that the hum is caused by a ground loop:
• Systematically remove and/or connect the audio grounds of the devices
in the signal path.
• Remember, for safety you must maintain connection to chassis ground.
Never lift a safety ground.
If you suspect the hum is not caused by a ground loop.
• Check the audio at an earlier stage in the audio chain.
• Low level equipment should be mounted away from power amplifiers to
avoid induction of this type of hum.
• Be certain that all audio wiring except for loudspeaker lines is well shield-
ed, and that low level wiring is not run parallel to and/or in close proximi-
ty to AC power wiring.
• Check the other equipment and the wiring to make certain that the signal
is not intermittent earlier in the chain.
• Check the integrity of all cables using a cable tester.
10
W EAK AND / OR D ISTORTED A UDIO
H UM AND / OR B UZZ
I NTERMITTENT A UDIO
®