Installation & Mounting
MTX recommends your new Thunder amplifier be installed by an Autho-
rized MTX retailer. Any deviation from specified installation instructions
can cause serious damage to the amplifier, speakers and/or vehicles elec-
trical system. Damage caused from improper installation is NOT covered
under warranty. Please verify all connections prior to system turn on !
1. Disconnect the vehicle’s negative battery cable.
2. Determine the mounting place for your MTX THUNDER amplifier. Keep in mind there should be sufficient air flow for
proper cooling. Mark the mounting holes from the amplifier to be drilled. Before drilling make sure all vehicle wires, gas
lines, brake lines and gas tank are clear and will not interfere with installation. Drill the desired holes and mount the MTX
THUNDER amplifier.
3. Install a positive (+) power cable from the vehicle’s battery through the firewall using a grommet or firewall bushing to
avoid cable damage from sharp edges of the firewall. Run the cable through the interior of the vehicle and connect it to
the amplifier’s +BATT terminal. Do Not connect to the battery at this time.
Note : Use only proper gauge wire for both positive and negative connections.
4. Install a circuit breaker or fuse within 20cm of the battery. This effectively lowers the risk of severe damage to you or
your vehicle in case of a short circuit or accident. Make sure the circuitbreaker is switched off or the fuse is taken out of
the fuse holder untill all connections are made. Now connect your positive power cable to the positive battery terminal
of the battery.
5. Grounding - Locate a proper ground point on the vehicle’s chassis and remove all paint, dirt or debris to reveal a bare
metal surface. Attach the ground wire to that contact point. Connect the opposite end of the ground wire to the GND
terminal on the MTX THUNDER amplifier.
6. Connect a Remote Turn-on wire from the source unit to the MTX THUNDER amplifier’s Remote terminal. If the source
unit does not have a dedicated Remote Turn-on lead, you may connect to the source unit’s Power Antenna lead.
7. Connect RCA cables from the source unit to the MTX THUNDER amplifier’s RCA Bi-level inputs. Both low and high
level signals can be used. Run all signal cables away from vehicle wiring, computers and power cables. If cables must
be crossed do so at a 90° angle. Use only high quality twisted pair interconnect cables to decrease radiated noise from
entering the system.
• Using RCA Connections: Simply attach a signal cable from source units RCA outputs to the amp’s RCA inputs. This pro-
vides input signal to the amp.
• Using Speaker Level Connections : If the source unit does not have RCA outputs, high level signals can be used by tak-
ing the supplied high level RCA adapter and connecting it to the vehicle’s rear speaker wiring. Connect the left negative
speaker wire to the green and black striped wire on the high level RCA adapter. Connect the left positive speaker wire to
the solid green wire. Do the same for the right speaker connection using the purple wire. Now plug the RCA connectors
into the amp’s inputs.
8. Connect your speakers to your MTX THUNDER amplifier’s speaker terminals using the right gauge speaker wire. Both
channels bridged can drive a 4 ohm minimum load for max power.
9. Double check all previous installation steps, in particular, wiring and component connections. Once verified, reconnect
the vehicle’s negative battery cable, turn the circuit breaker on or place the fuse in the fuse holder.
Note : Gain Levels on the amplifier should be turned all the way down (counter clockwise) before proceeding with adjust-
ments.
Troubleshooting
Problem
Cause
Solution
No LED indication
No +12V at remote connection
12V to terminal
No +12V at Power connection
12V to terminal
Insuffi cient ground connection
Verify ground connection
Blown power fuse
Replace fuse
Power LED on, no output
Volume on source unit off
Increase volume on source unit
Speaker connections not made
Make speaker connections
Gain control on amplifier off
Turn up gain
Signal processing units off
Apply power to signal processor
All speakers blown
Replace speakers
Output distorted
Head unit volume set too high
Lower head unit volume
Amplifier gain set too high
Lower amplifier gain
Balance reversed
Speakers wired L + R reversed
Wire speakers with correct orientation
RCA inputs reversed
Reverse RCA input
Bass is weak
Speakers wired out of phase
Wire speakers with correct phase
Not using MTX woofers
Buy MTX woofers
Blowing fuses
Excessive output levels
Lower the volume
Amplifier defective
Return for service