Connection
The acoustic properties of vehicle compartment tend to | 0 dB |
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cause oscillation due to resonance or unclearness of |
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sound due to standing waves at certain frequencies. |
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The band reject filter can solve the problems of |
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resonance or unclear sound with minimum influence on |
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the sound quality because it eliminates only the |
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frequencies causing resonance or standing waves. |
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■Adjustment method:
The band reject filter cuts only the limited frequencies to minimize influence on the sound quality. Therefore, its effect cannot be obtained unless the cutoff frequencies are set accurately to the frequencies causing resonance and standing waves. The band reject filter can be adjusted according to what you feel through your ears, but we recommend the use of a signal generator or a spectrum analyzer with a fine frequency measurement capability for the adjustment.
•Adjustment using a signal generator:
Output a sine wave, vary its frequency to find the frequencies at which the vehicle compartment resonates or volume increases (standing waves occur), and set the BAND REJECT FREQUENCY control to the position with which the resonance and standing waves disappear.
•Adjustment using a spectrum analyzer:
Output white noise (sound in which all frequencies are at a certain level), find the peak frequency observed on the spectrum analyzer, and set the BAND REJECT FREQUENCY control to the position with which the peak observed on the spectrum analyzer disappears.
Troubleshooting Guide
What might appear to be a malfunction in your unit may just be the result of slight misoperation or miswiring. Before calling service, first check the following table for possible problems.
PROBLEM | POSSIBLE CAUSE | SOLUTION |
No sound. | • Input (or output) cables are |
(No sound from one side.) | disconnected. |
| • Protection circuit may be |
| activated. |
| • The fuse may be blown because |
| the volume was too high. |
•Connect the input (or output) cables.
•Check connections by referring to "Controls".
•Replace the fuse with a new fuse and use a lower volume.
The output level is too small (or too large).
The input sensitivity adjusting | Adjust the control correctly |
control is not set to the correct | referring to “Controls”. |
position. |
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The sound quality is bad. (The sound is distorted.)
•The speakers cable are connected with wrong + / - polarity.
•A speaker cable is pinched by a screw in the car body.
•The switches may be set improperly.
•Connect them properly checking the + / - of the terminals and cables well.
•Connect the speaker cable again so that it is not pinched by anything.
•Set switches properly by referring to "Controls".
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