Operation Manual

4 Channel Amplifier - Applications
MXB-480/MXB-4125/MXB-4175
One 4 Channel Amplifier in Stereo Mode (Front-/Rear- Speakers) with
One 2 Channel Amplifier in Mono/Subwoofer Mode (Bass Amplifier)
Interconnect cable checklist:
•Connect the INPUT of the 4 Channel Amplifier to the head unit line outputs with good quality
RCA to RCA cables.
• Connect the OUTPUT of the 4 Channel Amplifier with the LINE LEVEL INPUT of the
designated Bass Amplifier (2 Channel Amplifier) with a further RCA cable.
• Connect the Front-/Rear Speakers with the terminal blocks (SPEAKERS / + CH1 -, + CH2 -,
+ CH3 - and + CH4 -) of the 4 Channel Amplifier.
• Connect the Subwoofer with the terminal block (SPEAKERS / + BRIDGED -) of the
designated Bass Amplifier (2 Channel Amplifier).
•The minimum final speaker impedance must not be below 2 Ohms for the 4 Channel
Amplifier, the total impedance of the Subwoofer(s) must not be below 4 Ohms. Too low
speaker loads result in too high heat dissipation and may cause the amplifier run into
protection.
• If you use more than one speaker (Subwoofer), make sure that both are connected in phase.
Incorrect polarity of the speakers results in total loss of bass response.
Caution
Be careful not to connect speaker (-) to the ground or vehicle chassis.
Control settings of the 4 Channel Amplifier:
FILTER SELECT (CH1/2 & CH3/4)
• If larger than 20 cm speakers are used, the FLAT position is recommended.
• For all smaller speakers (Ø8.7cm - Ø16cm) the Highpass-Position (HIGH PASS) is recommended, which eliminates the
lowest frequencies and protects the speakers from damage. Set the crossover-frequency between 60Hz - 150Hz, depending
of the size of the installed speakers. The Highpass adjustment can be done with the HIGH PASS control.
• In this configuration example the LOW PASS control is not used.
INPUT LEVEL (CH1/2 & CH3/4)
• Turn the INPUT LEVEL controls on the amplifier to 4V position.
• Turn the head unit volume control to about 80-90% of its full setting.
• Turn the INPUT LEVEL controls clockwise until you hear some distortion.
• Then turn back the INPUT LEVEL controls slightly until you can hear clean sound.
BASS BOOST (CH1/2 & CH3/4)
• Turn the BASS BOOST control into “0dB” - position.
INPUT SELECT
• The INPUT SELECT - switch must be in “4” - position.
Control settings of the Bass Amplifier (2 Channel Amplifier):
FILTER SELECT
• In 1 Channel/Mono-Mode select the Lowpass-Position (LOW PASS), which eliminates the higher frequencies. The
recommended crossover frequency ranges between 60 - 100Hz, depending on the size and response of the Subwoofer. The
Lowpass adjustment can be done with the LOW PASS control. In this configuration example the HIGH PASS control is not
used.
INPUT LEVEL
• see descriptions for 4 Channel Amplifier above
BASS BOOST
• The BASS BOOST - Control increases the bass level at 45 Hz max. +12dB.
Caution! Please use the Bass-Boost carefully. The additional boost may result in clipping or overload.
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