POWER AMPLIFIER OWNER’S MANUAL
Installation
Any deviation from the connection specifications recommended may cause serious damage to the amplifier, speakers and/or vehicle electrical system. Please
1.Disconnect the vehicle’s negative battery connection.
2.Place your Thunder amplifier at the predetermined mounting location. Using a felt pen, mark the exact position of the mounting holes on the mounting surface. Set the amplifier aside. Use a sharp, precise blade to cut small circles in the carpet and padding around the four marks denoting your mounting holes to expose the metal underneath. Use a center punch to make an indentation in the metal to ensure that you drill the exact position for the screws. Drill the four holes as marked.
3.Temporarily mount your Thunder amplifier.
4.Run a power cable from the vehicle’s battery through the firewall and through the interior of the vehicle connecting one end to your Thunder amplifier’s +BATT terminal and connect the other end to the positive post on the battery.
Note: Install a circuit breaker/fuse within 18" of the battery. This effectively lowers the risk of severe damage to your vehicle should a short circuit ever occur in the audio system. Do not install the fuse in the fuse hold- er until all installation steps have been completed.
Adjusting the Gain
1.Turn the gain control on the amplifier all the way down.
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 distor- tion disappears.
5.Follow steps
6.The amplifier is now calibrated to the output of the source unit.
Typical Speaker
Wiring Configurations
Stereo Amplifier
Bridge Mode Application
Impedance Requirement
4 ohm bridge minimum
2 ohm stereo minimum
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| 8 ohm |
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| 4 ohm |
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| 8 ohm |
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| 4 ohm |
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| + | - - + |
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| + | - - + |
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| L | L R R |
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| L | L R R |
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| AMP |
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| AMP |
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Two 8 ohm Speakers | Two 4 ohm Speakers | ||||||||||
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OK ok
5. | Find a good ground spot on the vehicle’s chassis and remove the paint to reveal bare metal at the contact |
| point. Attach the ground wire to that contact point and connect the other end of the ground wire to the |
| GND terminal of your Thunder amplifier. |
6. | Connect a Remote |
| gauge wire). If your source unit does not have a dedicated Remote |
| source unit’s Power Antenna lead. |
Troubleshooting Guide
Read this if you wanna be a
7. | Connect RCA cables from your source unit to your Thunder amplifier’s RCA input jacks. If RCA (low level) |
| output is not available, connect the included speaker (high level) connector (Thunder342) to the speaker |
| wires from the source unit. |
8. | Connect your speakers to your Thunder amplifier’s speaker terminals using 12 gauge minimum speaker |
| cable. |
9. | |
| Securely mount the amplifier. If everything is in order, reconnect the vehicle’s negative battery connec- |
| tion and begin adjusting your amplifier. |
Note: Be sure that the Gain Level on the amplifier is turned all the way down (counter clockwise) before pro- ceeding with adjustments.
Common Oversights
•The battery ground should remain DISCONNECTED at all stages of installation.
•Do not begin drilling until you have put your Thunder amplifier aside. Using the amplifier as a drilling guide may cause irreparable damage to the amplifier and void your warranty.
•Do not route any wires underneath or outside the vehicle body.
•Route signal wires (RCAs from source unit, speaker wires, etc.) away from power wires (power, ground, etc.) to avoid ground loops and other sources of noise.
PROBLEM | CAUSE |
No LED indication | No +12V at remote connection |
| No +12V at Power connection |
| Insufficient ground connection |
| Blown power fuse |
LED on, no output | Volume on head unit off |
| Speaker connections not made |
| Gain control on amplifier off |
| Signal processing units off |
| All speakers blown |
Output distorted | Head unit volume set too high |
| Amplifier gain set too high |
Balance reversed | Speakers wired L + R reversed |
| RCA inputs reversed |
Some balance reversed | Some Speakers wired L + R |
| reversed |
| Some RCA inputs reversed |
Bass is weak | Speakers wired out |
| of phase |
| Not using MTX woofers |
Blowing fuses | Excessive output levels |
| Amplifier defective |
SOLUTION
Supply +12V to terminal Supply +12V to terminal Verify ground connection Replace fuse
Increase volume on head unit Make speaker connections Turn up gain
Apply power to signal processor Replace speakers
Lower head unit volume
Lower amplifier gain
Wire speakers with correct orientation
Reverse RCA input
Wire speakers with correct orientation
Reverse appropriate RCA inputs
Wire with correct phase
Buy MTX woofers
Lower volume
Return for service
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