14
Noise/Hum
• Check the signal cable between the mixer and
the subwoofer. Make sure all connections are
secure. These problems usually produce crackling
noises or hum.
• If you are using two or more TH-18s powered
subwoofers, try plugging them all into the same
AC outlet panel or outlet strip. The purpose for
this is to connect them all to the same earth
ground point and reduce the possibility of creating
a ground loop.
• If connecting an unbalanced output to the TH-18s
balanced input, make sure the shield is connected
to the unbalanced ground and to pin 1 of the XLR.
Repair
For warranty service, refer to the warranty
information on page 17.
Non-warranty service for Mackie products is
available at a factory-authorized service center. To
locate your nearest service center, call our Tech
Support department at 1-800-898-3211, Monday-Friday,
during normal business hours, Pacific Time, to explain
the problem. Tech Support will tell you where the
nearest factory-authorized service center is located in
your area.
