Operation Manual

Speaker- and Audio-Connections: MXB480 / MXB4125

3-Channel Stereo-/Subwoofer-Mode

• Connect the RCA INPUTS of the amplifier to the head unit line outputs with appropriate

RCA cables. If your head unit is not equipped with pre-amplifier RCA line outputs you

can use the optional HI INPUTS (Highlevel Inputs). Connect therefore the speaker outputs of your

head unit with the enclosed cable plug. Check the Wiring Diagram below.

• Connect the frontspeakers with the speaker ouputs (SPEAKERS/ + CH1 -, + CH2 -) and the subwoofer

with the speaker outputs (+ BRIDGED - from CH3/4) of the amplifier by using appropriate cables.

• Ensure that the total speaker impedance load is not lower than 2 Ohms channel on channel 1/2 and

4 Ohms on subwoofer channel 3/4.

• Too low speaker loads result in too high heat development and may cause the amplifier run into

protection.

INPUT SELECT - switch

• Select here the 4CH-Position.

FILTER - selector channel 1/2

• If larger speakers (> Ø20 cm) are used, the FLAT position is recommended. A fullrange signal will be provided to the speakers.

• For all smaller speakers (Ø8.7cm - Ø16cm) the Position HIGH PASS is recommended, thereby the lower frequencies will eliminated

in the audiosignal. Set the cut-off frequency between 60Hz - 150Hz, depending of the size of the installed speakers.

The cut-off frequency is adjustable with the HIGH PASS controller.

• In this configuration example the LOW PASS - controller is not used.

INPUT LEVEL - controller channel 1/2

• Turn the INPUT LEVEL controller on the amplifier to 4V position.

• Turn the head unit volume controller to about 80-90% of its full setting.

• Turn the INPUT LEVEL controller clockwise until you hear some distortion.

• Then turn back the INPUT LEVEL controller slightly until you can hear clean sound.

REFERENCE NOTE: If this controller is cranked up too high, the amplifier produce distortions, which may cause a

“creeping death” of the amplifier (or the speakers). Usually this is called “Clipping”.

BASS BOOST - controller channel 1/2

• Turn the BASS BOOST controller into “0dB” - position.

FILTER - selector subwoofer channel 3/4

• In the Subwoofer-Mode mono bridged the FILTER - select must be in position LOW PASS, thereby the higher frequencies will be

eliminated in the audiosignal. Set the cut-off frequency between 60Hz - 100Hz, depending on the size of the installed subwoofer

The cut-off frequency is adjustable with the LOW PASS - controller. In this configuration the HIGH PASS - controller is not used.

INPUT LEVEL - controller subwoofer channel 3/4

• Turn the INPUT LEVEL - controller on the amplifier to 5V position.

• Turn the head unit volume controller to about 80-90% of its full setting.

• Turn the INPUT LEVEL - controller clockwise until you hear some distortion.

• Then turn back the INPUT LEVEL - controller slightly until you can hear clean sound.

REFERENCE NOTE: If this controller is cranked up too high, the amplifier produce distortions, which may cause a

“creeping death” of the amplifier (or the speakers). Usually this is called “Clipping”.

BASS BOOST - controller subwoofer channel 3/4

• The BASS BOOST - controller adjusts the bass boost from 0db to +12dB.Caution! Please use the Bass Boost carefully.

REFERENCE NOTE: Ensure always correct polarity for all connections.

Don’t connect any speaker cables to the vehicle’s ground.