20
| KH 805
Activating ground lift
If there is humming or buzzing noise coming from the subwoofer, first search for the cause of
the noise:
X
Disconnect all input and output signal cables from the subwoofer .
If the noise goes away, it is probably coming from the audio source or source cabling . It might
be possible to eliminate the noise by disconnecting the ground from the input signals
(activating ground lift) .
To activate ground lift:
X
Reconnect the signal cables and set the switch INPUT GROUND LIFT
B
to “LIFTED” .
This internally disconnects pin 1 of the XLR input sockets from the subwoofer electronics’
chassis ground (see table on page 10) .
For safety reasons, the electronics chassis ground is always connected to the mains
power earth pin . Never disconnect the earth pin of the mains cable from ground .
Even when ground lift is activated, the pins 1 of all audio inputs remain electronically
connected to each each other .
