THX subwoofers | page 15 |
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2.If the midbass range (the area of transition between Subwoofer and Satellite or L/C/R speakers) sounds weak:
See Section 7, PHASING TEST, on page 11. Reverse the position of the "SUBWOOFER PHASE" switch on the back panel of the subwoofer. The switch position that gives the most bass is correct.
3.If you hear a thump through the subwoofer every time you turn the rest of your audio system on (and your subwoofer is plugged in all the time):
Either the preamp, amp, receiver, or surround sound processor is generating the thump, and the subwoofer is reproducing it. Contact your dealer or the manufacturer of the other component.
4.If you hear a persistent hum or buzz through the subwoofer:
Because the subwoofer easily reproduces 60 Hz signals (the frequency of hum), it is often blamed for causing hum that originates elsewhere in the system. Always avoid running all speaker wires and RCA interconnect cables near to AC cords and component power supplies. Placing wires and cables close to AC lines often results in hum. If necessary, reroute your cables.
To identify the source of hum, remove all input cables to the subwoofer, but leave it plugged into the AC outlet. Set the "BASS LEVEL" switch to the "VARIABLE" position. Carefully turn the "BASS LEVEL" control up towards the "MAX" position. If you hear hum from the subwoofer, it is the source of the hum. If you hear no hum or much less hum, the problem is in another component or a ground loop.
For ground loop problems, when the subwoofer is plugged into a separate AC outlet, try plugging it into the same outlet as your amplifier or receiver. If that doesn't work, reverse the polarity of its AC plug. If you cannot solve the problem, call M&K or your dealer.
5.If you hear an unusual sound from the subwoofer when no signal or music is playing:
Try removing the input cables as described in Step 4 above. If the noise disappears, it is coming from another component. If it does not go away, contact your M&K dealer or the factory.
6.If the subwoofer will not play loud enough, AND it is connected to the SUBWOOFER OUTPUT jack on a
Make sure that the "BASS LEVEL" toggle switch is set to "VARIABLE." Set the "BASS LEVEL" control to the "MAX" position. If you get bass output, but it is not enough, then the processor's output level is too low.
Some surround processors/receivers/amps have very low output levels from their SUBWOOFER OUTPUT jacks. If you do not have enough gain when using the SUBWOOFER OUTPUT jacks on a
IF YOU NEED TO REPLACE THE EXTERNAL FUSE:
First, unplug the subwoofer from the wall AC socket. Remove the fuse cap. Look carefully at the fuse's wire filament inside the glass. If it is broken, replace the fuse ONLY with one identical in size and value. Using a larger fuse will void your warranty AND MAY CREATE A FIRE HAZARD. Plug the subwoofer back in. If it does not work, unplug it immediately, and contact M&K or your dealer for service.
