• Smart-Engage™ Auto-Turn-On - An auto-turn-on circuit is included within the amplifier. A remote turn-on
wire is not necessary when connecting the amplifier’s high-level input to a high-powered source unit (car
stereo). The amplifier will automatically turn on when music is received through this type of connection.
Note: Smart Engage™ is only active on the left input.
4. Input Sensitivity – The Input Sensitivity switch is used to set the proper input voltage range:
X1 POSITION: 100mV–1V (Typically for RCA Input)
X10 POSITION: 1V–10V (Typically for Speaker Level Input)
5. Gain Control – This feature is used to fine-tune the input sensitivity of the amplifier to the source unit’s output
level.
6. Low-Pass X-over Frequency Control with 24dB per octave Slope – This control allows the user to choose the
exact low pass frequency range the amplifier will play for the best possible performance. The upper end of
the crossover frequency point can be selected from 40Hz–200Hz at 24dB per octave.
7. Variable Subsonic Filter – This feature limits the lower end of the frequencies sent to the subwoofers. The
subsonic feature includes a control knob used to adjust subsonic setting from 15Hz-60Hz at 12dB per octave.
8. Parametric Equalizer – This one band parametric equalizer provides individual frequency, Q/bandwidth, and
+/-12dB gain adjustment controls. Any frequency from 30Hz to 80Hz can be chosen and boosted or cut up to
12dB. The “Q” ranges from 0.5 to 4.0 in value to allow a wide variety of bandwidth adjustment and address
the subtle tuning requirements common to mobile audio systems.
9. Remote Subwoofer Level Control (Remote Gain) – This port allows the use of the optional “remote level
control”. The Remote Subwoofer Level Control is a bass control module that can be installed in any location
within the vehicle for remote adjustments.
10. Phase Switch – The phase select switch allows you to invert the amplifier’s output phase by 180 degrees to
ensure the frequency interaction between the speakers is consistent within the vehicle. This also enables the
advanced bridging operation when using two amplifiers on one speaker.
11. StreetWires Connectors – All MTX amplifiers include StreetWires connectors for efficient current and
maximum voltage transfer.
12. Speaker Connection – Two sets of speaker terminals are provided for dual woofer applications. When
connecting a single woofer, use only one set of speaker terminals. (8 and 9 series are Bridgeable with a Phase
Switch)
13. Power Terminals – This is the main power connection for the amplifier. The power and ground wire size
should be the same gauge.
• GND – The ground wire from this connection must be attached to bare metal on the vehicle. The distance to
the ground should be as short as possible and no more than 18”.
• REM – To turn the amplifier on/off, this terminal must be connected to the source unit’s “remote or electric
antenna” wire.
• +12V – The power wire from this connection must be attached to the positive side of the vehicle’s battery.
• CAP+ - Capacitor Positive Input – The ideal connection point for the positive sides of the capacitor to increase
the amplifier’s performance.
• CAP- - Capacitor Negative Input – The ideal connection point for the negative side of the capacitor to increase
the amplifier’s performance.
Before Starting
MTX recommends that you have your new Thunder amplifiers installed by an authorized MTX retailer, preferably
MECP certified. If you do decide to do it yourself, make sure you have read the instructions carefully and have
the following tools:
• Electric drill
• Phillips bit or screwdriver
• 1/8” bit
• Wire cutters/crimpers
• Safety glasses
• X-Acto knife
Disconnect the vehicle’s negative battery connection. Any deviation from the recommended connection
procedures may cause serious damage to the amplifier, speakers, and/or vehicle electrical system. Please
double check the connections before turning the system on.
