Tools Required
J 39916-A CD and Cassette Diagnostic Kit
Important: Always compare the following speakers:
• The front speakers to the front • The rear speakers to the rear • The speakers may be different. • The mounting environment may cause the speakers to sound different.
The tones are used in order to test and evaluate coaxial speakers or other complex speaker systems. The 3 basic tones are listed below:
| • | The 50 Hz sine tone |
| • | The 500 Hz warble tone |
| • | The 9 kHz spectral tone |
| The combination tone is a blend of the 3 tones. |
Bass/Sub-Woofer Test (50 Hz Sine Tone)
The 50 Hz sine tone is used in order to evaluate the bass response of an audio system. This tone is also helpful in evaluating audio systems which have separate sub-woofer amplifiers and speakers.
Midrange Speaker Test (500 Hz Warble Tone)
The 500 Hz warble tone is used for the evaluation of midrange speaker response. The tone is qualified as a warble sound. At midrange frequencies use a warble tone rather than a sine tone.
The location of a warble tone source, such as a speaker, is easier to identify. A normal sine tone can set up a standing wave within a vehicle. A standing wave may cause difficulties in determining the source location.
Tweeter Test (9 kHz Spectral Tone)
The 9 kHz spectral tone is used for tweeter or high frequency evaluation. The tone is a section of frequencies of equal amplitudes ranging from 8.5 kHz-- 9.5 kHz. The sound is similar to crickets chirping.
This type of tone is used for the following reasons:
| • | The source is easy to locate, much like the warble tone. |
| • | The spectral tone is easier to identify for those people with high end hearing loss problems. |
All Speaker Test
The combination tone may be used in order to diagnose numerous audio problems, such as distorted sound or no sound from speaker(s). When using the combination tone, comparative DC voltage measurements may be made on the speaker terminals provided the fade and balance controls are in the detent position. With these voltage measurements, a determination may be made in the diagnosis of a speaker or amplifier.
Speaker/Grill Rattle Test (50 Hz-8 kHz Swept Sine)
A portion of the tape may be used in order to diagnose speaker and grille rattles. This portion contains the following tests:
| • | The first test is 2 tones played back-to-back. |
| • | The second test is a variable frequency tone, but the frequency change is at a much slower rate. |
Both of the tests may be used in order to repair a speaker rattle or buzz.
After the condition has been isolated, the fade and the balance controls may be set to the proper location. The test tones may then be played in the specific problem area.
Motor Speed Test
There is a 2 minute time period marked in this section of the tape for the purpose of checking the cassette tape motor speed. This portion of the diagnostic tape may be used in order to verify complaints of abnormal sound from the cassette tape player.
In some cases, the improper tape motor speed may cause audio abnormalities. If the time taken for this is between 1 minute and 56 seconds to 2 minutes and 1 second, the tape motor speed is within tolerance.
Noise Diagnosis (Dead Space)
This portion may be used for the following noise diagnosis:
| • | Alternator whine |
| • | Switch pops |
These noises can be easily detected during dead space (blank space between the songs). This portion of the diagnostic tape may be used in conjunction with Diagnostic System Check - Radio/Audio System .
