Purpose

• There are two reasons why you may wish to bypass a powered subwoofer's internal amplifier. While relatively uncommon, amplifiers do fail on occasion due to thermal breakdown or mechanical problems. Replacing or repairing a subwoofer amplifier can be costly, so you may look for other options to power the speaker. You may also want to use your external amplifier if it is better than the subwoofer's internal amplifier.
  
  

Usage

• To use a powered subwoofer with an external amplifier, use a screwdriver to open the subwoofer enclosure, then disconnect the speaker from the internal amplifier. Then use a length of speaker wire to connect the speaker to the external amplifier. Since powered subwoofers are only meant to be used with internal amplifiers, it may be necessary to drill a hole in the enclosure for the new speaker wire. Alternately, you may be able to run the wire through a port in the enclosure.
  
  

Rehousing the Speaker

• Another option for bypassing the internal amplifier is to remove the speaker within the enclosure and install it in a new enclosure specially designed for use as a passive subwoofer. This is much more labor intensive, but may make sense if you have woodworking or speaker design experience.
  
  

Considerations

• Powered subwoofers are designed to perform at prescribed levels, and the internal amplifiers are always chosen to provide an optimal amount of power to the internal speakers. When using a powered subwoofer with an external amplifier, ensure that the amplifier's output power does not exceed the speaker's wattage rating to prevent speaker failure. Similarly, ensure that the amplifier's output impedance matches the speaker's impedance rating. An impedance mismatch could lead to amplifier failure.