Control Panel :
Ground Terminal (GND) : A proper ground is required for your amplifier to operate at peak performance. A short
ground cable the same diameter as the power cable should be used to attach the ground terminal directly to
the chassis of the vehicle. Always remove paint, dirt or debris to expose bare metal where the ground will be
attached.
Remote Terminal (REM) : The amplifier can be turned on by applying 12 volts to this terminal. Typically this volt-
age is supplied by a wire from the source unit marked “remote” or “power antenna”.
(+12V) Power Terminal : This is the main power input for the amplifier and must be connected directly to the posi-
tive terminal of the vehicles battery for proper operation. Use caution when installing (+12V) power cable in the
vehicle. Avoid running this cable parallel with RCA cables, antennas, or other sensitive equipment due to massive
currents that can induce noise into the audio system. It is also very important to have a tight, secure connection
for maximum performance. MTX recommends using 8 to 10mm
2
power wire with the MTX RT50.4M amplifier.
Speaker output on ISO connector (Speaker output) : These are the speaker outputs to be connected to the car
speakers. Connect the car ISO speaker connector here. You can use the included extension cord if needed.
Speaker high level input on ISO connector (High Level Input) : This is the high level speaker input to be con-
nected to the car radio.
You can use the included extension cord if needed.
PowerOn/Protection LED - The LEDs illuminate red when the amp is switched on. When the amps is in short
circuit, low impedance or thermal protection, the LEDs are blinking.
Remote switch (Remote) : Allows you to choose between the usual wired remote (“Cable” position when using
the remote from in power connector) or automatic remote (Auto position). If a remote wire is available behind
your head unit, it is better to use it.
Gain Control (Gain) : The gain control matches the input sensitivity of the amplifier to the source unit being used.
The operating range varies from 100mv to 6V.
Adjusting the gain
1. Turn the gain control on the amplifier all the way down (counter clockwise).
2. Turn up the volume control on the source unit to approximately 3⁄4 of maximum.
3. Adjust the gain control on the amplifier until audible distortion occurs.
4. Adjust the gain control down until audible distortion disappears.
5. The amplifier is now calibrated to the output of the source unit.
RCA Inputs connector (RCA Inputs) : Used with source units that have RCA or Line level outputs. Source units
need a minimum level of 100mV output for proper operation of the amplifier. A wire harness is included in the
box. MTX recommends only high quality twisted pair cables (such as StreetWires) to decrease the possibility of
radiated noise entering the system.
