Pioneer GM-D8400M Owner's Manual - Page 6

Setting the Unit Setting the Gain properly • This unit is equipped with a protective function to prevent malfunction of the unit itself and speakers from too much output, improper use or improper connection. • When outputting sound at high volume etc., this function will cut off the sound output in a few seconds. But this is not a malfunction. When you turn down the volume of the head unit the sound output will be restored. • If sound output is cut, the gain control of this unit may be improperly set. To ensure continuous sound output at increased volume of the head unit, set the gain control of the amplifier to a proper position according to the preout maximum output level of the head unit. Gain Control of This Unit Preout level: 2 V (Standard: 500 mV) Preout level: 4 V Preout level: 6.5 V • The above illustration shows the gain set to NORMAL. There is no need to decrease the volume of the head unit and too much output is controlled. Relationship between the gain of the amplifier and the output power of the head unit Power Normal gain Power Maximum gain Equal power Head unit volume steps Amplifier gain (normal) Head unit volume steps Amplifier gain (maximum) • If you raise the gain of the amplifier to an improper level, only distortion is increased and the power increases only slightly. Signal waveform when outputting at high volume by the gain control of the amplifier Normal gain Equal power Maximum gain Signal waveform Amplifier gain (normal) Signal waveform Amplifier gain (maximum) • With high output the signal waveform is distorted, if you raise the gain of the amplifier the power changes only slightly. • If you decrease the volume of the head unit and set the gain control of the amplifier to the proper position but still the sound cuts out from time to time, contact the nearest authorized PIONEER Service Station. 5