[. . . ] When the unit is used in the ACC ON position without turning the engine ON, it depletes the battery. There is a Protection function installed in the unit to protect the unit and speakers from various problems. To prevent damage to the machine, take the following precautions: · Be sure the unit is connected to a 12V DC power supply with a negative ground connection. Do not install the unit in a spot exposed to direct sunlight or excessive heat or humidity. [. . . ] This control adjusts the frequency band output from this amplifier SUB. Set to this position and make bridged connections to use as a high-power The input for terminal A is output from amplifier A, while the input for terminal B is output from amplifier B. From the Kenwood center unit Switch is set in the remote position, the bass boost amount and frequency offset can be controlled from the center unit. Center unit display "Flat"/ "OFF"/ "1" "+6"/ "1"/ "2" "+12"/ "2"/ "3" "+18"/ "3"/ "4" Center unit display "Normal" Setting Bass boost OFF (Flat) Bass boost +6 dB Bass boost +12 dB Bass boost +18 dB From the Kenwood center unit. For the center unit control method and setting display, refer to the Instruction Manual for the center unit. There may be cases when the center unit can't set the "Bass boost +18dB" or "Frequency Offset". Every time the button is pressed, 7 fixed colors and the variable color change. You are notified of the unit's condition and malfunction (Protection function) by the indicator. When the battery wire is too small or too long and can't supply enough current. When the unit has failed and direct current voltage is generated to the speaker's output. If the indicator doesn't quit blinking, contact your Kenwood dealer. When you wish to use the unit as a stereo amplifier, stereo connections are used. the speakers to be connected should have an impedance of 2 or greater. When multiple speakers are to be connected, ensure that the combined impedance is 2 or greater for each channel. When using an RCA cable with a ground lead attached, connect the ground lead to this terminal. Only Kenwood center unit models sold in 1999 or later with a "EXT. Also, a maximum of 3 power amplifiers can be operated at the same time. When you wish to use the unit as a highoutput monaural amplifier, bridged connections are used. When multiple speakers are to be connected, ensure that the combined impedance is 4 or greater. There are cases when operation may not be possible due to wiring wire type and length. [. . . ] Prepare commercially-available coil and capacitor with the closest ratings to the results calculated from the formula above. 25 (µF) and the coil rating should be as close as possible to 5. If you wish to bridge-connect a speaker, the speaker impedance must be no less than 4 ohms. Connecting a speaker with an impedance lower than 4 ohms may damage the unit. [. . . ]