Advertisement
Problems & solutions
"The subwoofer is making a humming noise"
The Kompakt 30 system employs a powerful trans-
former and an amply sized power pack, which are
necessary to produce the system's high output.
These components may cause a barely inaudible
constant hum, which you may be able to hear
from the rear of the subwoofer when there is no
music or other sound in the room. This electri-
cal hum can only be avoided using very expensive
high-end componentry, and it is perfectly normal
for the large majority of active speakers. As soon
as the loudspeakers receive a signal, the hum is
masked by the audio output and disappears.
However, if the hum remains clearly discernible
from further than one metre away, this may in-
dicate a fault – especially if the subwoofer is not
connected to any other devices. If the subwoofer
is already connected to other devices, the hum
may be caused by an equalising current, e.g., be-
cause the external devices have differing electric
potentials.
If you think this may be the case, try the following
methods to remove the hum:
1. The subwoofer is connected to a different elec-
trical circuit than the other components. Make
sure that all the connected devices (including any
computers) are powered from the same electrical
circuit, i.e., the same mains socket.
2. The antenna connected to the audio system
or TV has a different ground potential to the an-
tenna socket. To test this, simply disconnect all
the antenna cables from the wall socket. If this
makes the hum disappear, you will need a ground
breaker (available from most electronics stores).
Insert the ground breaker between the antenna
socket and the TV/receiver.
3. A line filter (to be purchased separately) can
also be useful for hum removal. Note that you will
need to connect all your electrical devices to the
line filter. Make sure you can return the line filter
for a refund if it does not produce the desired
results.
4. Some types of power multiboxes are also known
to produce hum. Try eliminating your multibox
and plug the subwoofer's power cable directly
into the mains socket.
5. Unplug the mains cable, rotate the connector
plug by 180° (if your mains socket allows it), and
plug it back into the mains socket.
6. If you have trouble locating the source of the
hum, check whether the subwoofer is less noisy
when you plug it into the mains connection in an-
other room (e.g., using an extension cable). Also,
try disconnecting the subwoofer's cinch cable
from the receiver to see whether the hum is
caused by one of the other connected devices.
7. Try adding an additional earthing signal; fasten
a wire (e.g., spare speaker cable) to one of the am-
plifier's metal screws, and fasten the other end to
a ground point (e.g., heater pipe, computer hous-
ing).
11
· Kompakt 30
Advertisement
