8 EnglishThe acoustic properties of vehicle compartment tend to cause oscillation due toresonance or unclearness of sound due to standing waves at certain frequencies.The band reject filter can solve the problems of resonance or unclear soundwith minimum influence on the sound quality because it eliminates only thefrequencies causing resonance or standing waves. Adjustment method:The band reject filter cuts only the limited frequencies to minimize influenceon the sound quality. Therefore, its effect cannot be obtained unless thecutoff frequencies are set accurately to the frequencies causing resonanceand standing waves. The band reject filter can be adjusted according to whatyou feel through your ears, but we recommend the use of a signal generatoror a spectrum analyzer with a fine frequency measurement capability for theadjustment.• Adjustment using a signal generator:Output a sine wave, vary its frequency to find the frequencies at whichthe vehicle compartment resonates or volume increases (standing wavesoccur), and set the B.R.F. FREQUENCY control to the position with which theresonance 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 theB.R.F. FREQUENCY control to the position with which the peak observed onthe spectrum analyzer disappears.Band Reject FilterFrequency0 dBTroubleshooting GuideWhat 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 followingtable for possible problems.PROBLEM POSSIBLE CAUSE SOLUTIONNo sound.(Blown fuse.)• Input (or output) cables are disconnected.• Protection circuit may be activated.• Volume is too high.• The speaker cord is shorted.• Connect the input (or output) cables.• Check connections by referring to "Protection function".• Replace the fuse and use lower volume.• After check the speaker cord and fixing the cause of the short,replace the fuse.The output level is too small(or too large).• The input sensitivity adjusting control is not set to the correctposition.• Adjust the control correctly referring to "Controls".The sound quality is bad.(The sound is distorted.)• The speakers wire are connected with wrong + /-polarity.• A speaker wire is pinched by a screw in the car body.• The switches may be set improperly.• Connect them properly checking the + / - of the terminalsand wires well.• Connect the speaker wire again so that it is not pinched byanything.• Set switches properly by referring to "Controls".The sound does not changeeven when you have changedit with the Amplifier Control.• The AMP CONT has been turned "OFF". • Turn the AMP CONT "ON".The set value cannot bechanged by the AmplifierControl of the unit.• The AMP Control of the Center Unit is being used. • Release the AMP Control mode of the Center Unit.The Amplifier Control cannotbe operated from the CenterUnit.• An incorrect ID number is used for the Master amplifier.• The ID number of the amplifier has been changed.• Always set the ID number of the Master amplifier to "0".• After you have changed the ID number of an amplifier, turn Offthe POWER switch of the Center Unit first, then turn it On again.