2. GND: This is the ground connection for the amplifier and must be connected directly to the metal chassis
of the vehicle for the amplifier to operate properly. A properly grounded amplifier can be run harder and
longer then a poorly grounded amplifier. The ground on the amplifier should be as short as possible and
be connected directly to the vehicle’s metal chassis. Do not connect to factory bolts of ANY kind. When
attaching the ground to the chassis, sand all the paint away from the contact point, a grounding block like the
StreetWires GT4 should be used whenever possible, this piece of equipment has 5 times the surface area a
normal screw has.
The gauge of the power and ground wire is often an overlooked aspect of amplifier installation. The more
power the amplifier receives, the more power it will produce. Power cables have a natural resistance, and
will lose voltage by the time the power makes its way to the amplifier. The larger gauge (diameter) wire will
hold more voltage over longer runs. Also by having a larger diameter ground wire, the amplifier can run
more efficiently. MTX recommends using a minimum of 8 gauge power and ground cables to get the best
performance.
3. REM: This connection turns the amplifier on and off and needs to be connected to a remote Turn-on wire from
your source unit if you are using a low level input connection.
Note: When numerous amplifiers are used in the same system, look into using a relay with a separate power wire
connected to an alternative power source to take the strain off the source unit. Normal source units can only
keep a constant 12 volts to 2 maybe 3 amps. This wire should also be run on the away from the RCA cables.
Double check all the previous connection installation steps, in particular, the speaker and power wiring.
Securely mount the amplifier. If everything is in order, reconnect the vehicles negative battery connection and
begin following the feature setup and adjustment steps.
Feature Setup and Adjustments
1. Selecting The Input Sensitivity Range – Before you turn on your system, you must select the proper input
sensitivity range on your amp using the button labeled INPUT SENS located in the GAIN CONTROL section of
the control panel.
• Setting for aftermarket Source Units: Refer to your aftermarket owner’s manual for line level output
specification. If the specification is not available, please follow the instructions listed below.
X1 POSITION: 100mV – 1V (Typically for RCA Input)
• Setting for factory (OEM) Source Units: To check the amount of voltage that is present from the source
unit, take a multi meter, or a volt/ohm meter, on the A/C setting, (range from 100mv up to 10 volts) attach the
positive and negative leads directly to any exposed speaker. It will not matter if the polarity is correct, it will
read the same amount of voltage.
X10 POSITION: 1V – 10V (Typically for Speaker Level Input)
Note: It is important not to have the amp set up to receive a low voltage signal and give it a high voltage signal.
Doing this can cause damage to the amp.
2. Adjusting The Individual Gain Control/s – Before you start setting your amp gains, be sure to defeat all “EQ’s”
(“off” position). You want to set the gain levels properly BEFORE applying any equalization.
Start with the source unit’s volume around 3⁄4 of the way up, and the gain on the amp all the way down
(counterclockwise). Slowly increase the gain clockwise until the speaker starts to distort. Immediately
decrease gain until the distortion goes away. This will be a good reference point on the volume control to
where the signal starts to distort. Remember every CD will be different, use common sense and constantly
listen for obvious distortion and adjust volume accordingly. The gain on the amp has nothing to do with how
much power the amp can produce, just how fast the amp puts out max power. Just like in an automobile, full
throttle is very rarely needed.
Note: No front and rear gain matching is required if the Dual Mono feature is on. Use the rear gain control only
for adjusting the gain for all channels.
3. Adjusting the Hi, 12dB / Low, 24dB Mono @ 85Hz Switchable X-over Frequency Controls–
• Setting For Subwoofers: First enable the electronic crossover by selecting the “ON” position of the X-
OVER switch, then select the “L-PASS” (Low pass) position on the L-PASS/H-PASS switch. By selecting this
setting, the amp crosses the signal over at 85Hz with a 24dB/Oct roll off. Meaning the signal tapers off fairly
quickly at frequencies over 85Hz.
