User manual SONY XM-4020

[. . . ] This unit is designed for negative ground 12 V DC operation only. ⷠUse speakers with an impedance of 1 to 8 ohms (2 to 8 ohms when used as a bridging amplifier). ⷠDo not connect any active speakers (with builtin amplifiers) to the speaker terminals of the unit. Doing so may damage the active speakers. [. . . ] Do not attempt to test the protection circuits by covering the heat sink or connecting improper loads. ⷠDo not use the unit on a weak battery as its optimum performance depends on a good power supply. ⷠFor safety reasons, keep your car audio volume moderate so that you can still hear sounds outside your car. If the fuse blows again after replacement, there may be an internal malfunction. When replacing the fuse, be sure to use one matching the amperage stated above the fuse holder. Never use a fuse with an amperage rating exceeding the one supplied with the unit as this could damage the unit. Protection circuit This amplifier is provided with a protection circuit that operates in the following cases: -- when the unit is overheated -- when a DC current is generated -- when the speaker terminals are short circuited. The color of the POWER/PROTECTOR indicator will change from green to red, and the unit will shut down. If this happens, turn off the connected equipment, take out the cassette tape or disc, and determine the cause of the malfunction. If the amplifier has overheated, wait until the unit cools down before use. If you have any questions or problems concerning your unit that are not covered in this manual, please consult your nearest Sony dealer. ⷠIf your car is equipped with a computer system for navigation or some other purpose, do not to remove the ground wire from the car battery. If you disconnect the wire, the computer memory may be erased. To avoid short circuits when making connections, disconnect the +12 V power supply lead until all the other leads have been connected. Note When you tighten the screw, be careful not to apply too much torque* as doing so may damage the screw. * The torque value should be less than 1 N· Note Make sure that the line output from the car audio is connected to the jack marked "R (MONO)" on the unit. You can select your desired frequency of the LPF side (50 Hz or 80 Hz). * (XM-4020) ** If you have the factory original or some other car audio without a remote out-put on the amplifier, connect the remote input terminal (REMOTE) to the accessory power supply. Connect the +12 V power supply lead only after all the other leads have been connected. ⷠBe sure to connect the ground lead of the unit securely to a metal point of the car. A loose connection may cause a malfunction of the amplifier. ⷠBe sure to connect the remote control lead of the car audio to the remote terminal. [. . . ] The output signals to the subwoofer will be the combination of the both right and left output signals. Car audio Autoradio LINE OUT You can select your desired frequency of the LPF side (50 Hz or 80 Hz). When using passive crossover networks in a multi-speaker system, care must be taken as the speaker system's impedance should not be lower than that of the suitable impedance for this unit. ⷠWhen you are installing a 12 decibels/octave system in your car, the following points must be considered. [. . . ]