Here's a common problem with stereo and home theater systems – and a quick solution. You've got a pile of speaker wires on the floor and you don't know where they go, or you don't know which is right or left channel. The most difficult and time-consuming way to sort it out is to untangle the wires and follow them inch-by-inch to the speaker(s). The easiest way to trace the wires is with a common household battery (either AA or AAA – nothing larger). Speakers and speaker wires have a + and – minus polarity and so do batteries. Hold one speaker wire to one of the battery terminals (+ or -) and the other wire to the remaining battery terminal. As you hold the battery and wires, take one of the wires and repeatedly touch the terminal and disconnect it in sort of a brushing motion. If the speaker is working and the wires are connected, listen for a static sound from the speaker each time the wire touches the terminal. (Note: if you have speakers in multiple rooms, an assistant may be helpful). When you identify the speaker, mark the location of the speaker (bedroom, den, etc.) or speaker channel (left, right, surround, etc.) on the wire with a piece of masking tape or a small label.
If you hear nothing from any speaker, check the wire connection on the back of the speaker and make sure you are using a fresh battery that still has a charge. If you still hear nothing, the problem may be a defective speaker or a defective wire between the amplifier and the speaker. If you suspect the speaker may be defective, try connecting the battery directly to the speaker with a short piece of wire. If you still hear nothing, the speaker is likely the problem. If you suspect wiring is the problem, check the speaker wires carefully, household pets or mice can chew through speaker wires; even a small break in the wire can cause problems.
Making sure that all speakers are connected correctly, or 'in phase' is also important for good sound but beyond the scope of this article. For more information, read How to Connect Speakers to a Receiver.