Repairing Subwoofer Speakers for Home Theater Audio Systems

Most home theater audio system setups include a subwoofer speaker either powered or passive subwoofers. Powered subwoofers are speaker enclosures that have a speaker mounted inside and also have a power amplifier inside the enclosure to power this speaker only. A passive subwoofer has a speaker mounted inside the enclosure and requires an external audio amplifier to send the audio signal to the speaker. Powered subwoofers are the most common for the average home theater system and the passive models are usually in more expensive home theater systems, needing an additional power amplifier. Home theater combination receivers are available in 5 channel and 7 channel models. The five channel receivers have five separate amplifiers inside, 2 amplifiers for front speakers left & right, 2 amplifiers for rear speakers left & right and 1 amplifier for the subwoofer.

If this is the first time you are setting up a powered subwoofer to your home theater system, follow the manufacturer’s installation instructions for wire connections and power requirements. If the subwoofer has no sound coming out of it check for;

• Power plug connected to AC outlet and the outlet has power.
• Check audio signal wires (usually RCA cable) to make sure the wires are plugged/ connected to speaker input.
• Check if there is a switch on back or front of preamp/receiver to turn on audio signal to subwoofer.
• Check that the other end of RCA plug wires are connected to the subwoofer output or (sub out) of the preamplifier or receiver and not to a speaker output which is the amplifier output.
• Check for blown fuses on subwoofer or power reset switch.
• Hook up the subwoofer to one of the main channels to preamp outputs, if there still no sound it is likely the subwoofers amplifier is bad. If so send back to manufacturer for repair.
• If the enclosure has a burnt odor, return to factory for repair.

If there is a humming noise or static check:

• The subwoofer is not near a large appliance or television.
• The input cable at the preamp/receiver in fully plugged in.
• The preamp/receivers other channels are working ok.
• Connect another speaker to the subwoofer output of preamp /receiver for hum or noise.
• If there is still hum most likely the preamp/receiver has a problem with subwoofer output.

Follow the same troubleshooting procedures if subwoofer has been connected and working and suddenly /recently stopped. Most powered subwoofers have no user serviceable parts because the amplifier and speaker are matched and compatible at factory.

For Passive Subwoofers, if there is no sound, repeat the above instructions then continue as follows:

• Remove speaker grill and see if speaker cone is damaged or has any holes in it, if so send back to manufacturer for repair or replacement. ( small holes or tears can be repaired with glue , but not recommended for novices)
• Remove speaker from enclosure (if possible) and check for blown fuse or loose wires.
• Check power amplifier for blown fuses on speaker output.
• Check that amplifier has enough wattage to drive subwoofer, compare power rating of subwoofer to power amplifier output wattage.
• If amplifier is overheating or shuts down, it is probable the speaker is blown.
• Return enclosure to manufacturer for repair.

Passive subwoofers are usually more expensive and of audiophile quality which are used in high end audio systems. In low to mid priced subwoofers it usually isn’t cost effective to make repairs unless covered by a warranty. If the speaker is blown you may be able to replace just the raw speaker with the same exact size, model and brand. The enclosure was designed for the speaker that is mounted in enclosure from the factory. If a replacement speaker is installed, the performance and output frequencies may be differ than the original. I would suggest only a professional attempt replacing or reconing the raw subwoofer speaker. 

Home theater speakers and ideas or designs of speakers and types of speaker to use in a speaker enclosure. How to build your own for diy and high end audio for the audiophile, pro audio loudspeakers new or rebuilt reconed raw speaker with crossovers hook up to the components and setup the rear speakers and front speakers or use a powered subwoofer. Buy new audio cables, reconed, refurbished, amplifiers or Altec Lansing,  Altec, TAD, JBL, bose, klipsch, horn, tweeter, driver, cables, audio system with Crown, subwoofers,  power amp,  amps, surround sound. Your new 5.1, 7.1 for sound, audio, speaker cables, cables and connectors, adapters, 5 channel, reviews, ratings,  vintage, music, stereo, stereo system, hi fi, high end.