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V-1250THX subwoofer
If you want to experiment, move the main speakers or subwoofer towards or away from your listening
position, in small increments. When you hear the best combination of stereo image localization and
focus with solid midbass impact and output, you have the ideal location.
If you have two subwoofers, perform one test for each subwoofer. When you perform each test,
make sure the other subwoofer is not operating by either unplugging its input cable or its power cord.
8. TROUBLESHOOTING
Your subwoofer amplifier circuit provides high reliability, and, if necessary, easy modular parts
replacement. This guide will help solve or diagnose most problems that may occur. Remember, if a
fuse blows, you must replace it with the correct value to avoid fire hazards and to maintain the warranty.
1. If your subwoofer has no output:
a.
Make sure that the subwoofer is plugged into an AC outlet.
b.
If the "BASS LEVEL" switch is set to "VARIABLE", make sure that the "BASS LEVEL" control
is set above the "MIN" position. Rotate it clockwise if it is set to the "MIN" position. Make sure that
the SUBWOOFER OUTPUT level control on your processor or amp is set above the "MIN" position.
c.
If the "BASS LEVEL" control is set to "THX", make sure that any SUBWOOFER OFF/ON switch
(found on the controller front or rear panel or remote control) is set to ON. Make sure that the
SUBWOOFER OUTPUT level control on your THX controller is set above the "MIN" position.
d.
Check the red LED on the subwoofer's back panel. If the LED is not lit, check the AC fuse next
to the LED. Unplug the subwoofer before changing the fuse. See instructions on Page 15. If the
element inside the fuse is broken, replace the fuse. If it blows again, contact your dealer or M&K.
e.
If the red LED is still lit, set the "BASS LEVEL" switch to the "VARIABLE" position. Turn the
"BASS LEVEL" control to "MIN". Plug a standard RCA cable into the "LEFT/MONO" "FROM PREAMP"
jacks. Lightly touch the plug at the free end of the cable. Then turn the "BASS LEVEL" control
clockwise. If you hear a buzz or hum from the subwoofer when you touch the cable, the subwoofer is
working. Look elsewhere in your system for the problem. If you hear no output, contact your dealer
or M&K for service.
f.
Make sure your cables are OK. Re- check all connections and replace any defective cables.
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 13. 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:
