Test Those Speakers Before Doing Any Repair Or Replacement (B12020E)

Speaker Check Mode Test

This test applies a single frequency to each speaker in a specific order to make sure its output circuit is working and the speaker is delivering sound. You'll find it under Audio System Self-Diagnostic Function  . It's part of the audio system self-diagnosis, and most models have it. A designated button on the audio unit switches the test frequency to the next speaker.

Audio Diagnostic CD Tests

These tests use the fader and balance settings to isolate a problem or noise to a single speaker. You'll find them under Audio System Sound Quality Diagnosis  . To run them, you'll need the Audio Diagnostic CD (T/N 07AAZ-SDBA100), a required special tool available from Acura parts stock. This CD has 53 different tracks. Most of them are single or sweeping frequencies for checking speaker performance or resonant noises. Several are musical selections for checking your repairs.

Make sure the bass, treble, fader, and balance settings are set to their center  positions before running these tests. And make sure you note your client's original settings, and restore them once you're done. The procedure tells you which track to use for each test.

Speaker Voice Coil Resistance Test

This test checks the speaker voice coil impedance (speaker ohms) for an open. You'll find it under Speaker Test/Replacement  . It's usually done during speaker removal and installation, or when you've got a speaker that failed the Speaker Check Mode Test and you want to find out if it's because of that speaker or another circuit.

This test is a low-resistance measurement, so make sure you zero out your digital multimeter. For details, check out self-study module ELC31, How to Measure Resistance  , in Online University.

Speaker Troubleshooting Tips

Here are some handy tips to remember when doing speaker troubleshooting:

• How the audio system is set up and played can have a big impact on speaker health. Most speaker damage comes from having the volume cranked up with the bass and treble settings maxed out. If you've got the volume cranked up, drop the bass and treble levels. Have the service consultant talk to your client about this. A little education can help prevent more speaker failures.
• To duplicate some speaker problems, you might need to play the audio unit for a while or play a specific type of music. Find out from the consultant how long your client played the audio unit before he or she noticed the problem and whether it happened with everything played or just one song or type of music.
• Don't  play the audio diagnostic CD with your client around. Certain tracks can cause noises that you wouldn't normally hear.
• On some models, some speakers (like the front door speakers and tweeters) are wired to one audio unit output in parallel pairs. When running the Speaker Check Mode Test, you can't  test those two speakers separately. So, make sure you're getting sound from both  speakers. You might have to unplug one of the parallel speakers to check that the other is working.
• For removing and replacing speakers, power tools are a bad  idea! Over-torquing mounting bolts could cause bass distortion that can make the original speaker, or even the replacement speaker, deliver poor sound quality. Each bolt has a torque spec listed in ISIS, and it's usually very low: about 4 to 7 N.m (3 to 5 lb-ft)  . Your best bet: a commercially available torque screwdriver.

Need more troubleshooting info? Be sure to check out these resources:

ISIS

• Speaker Test/Replacement
• Audio System Self-Diagnostic Function
• Audio System Sound Quality Diagnosis

Online University 

Self-study module ELC08, Audio System Diagnosis