Level Matching (setting gains) on a Stinger Amplifier – Stinger Solutions

The Stinger amplifier's gain dial should be matched to the source level. This tutorial uses the Stinger MT-1000.1, with input sensitivity from 0.2V (min) to 6V (max).

The RCA output voltage from the source must be known.
- If the Stinger amp is installed with an aftermarket radio, refer to the owner’s manual included with the radio.
- If the Stinger amp is installed with a factory radio and an LOC (line out converter), the audio output voltage from the LOC must be measured with a test tone and a multimeter set for AC voltage.
- If the Stinger amp is installed with an audio processor such as an Epicenter, the audio output voltage from the processor must be measured with a test tone and a multimeter set for AC voltage.

Test tones

Click here for test tones.

From a factory radio without a factory amplifier:

Disconnect all speakers from the radio to prevent damage.
Set the bass, mid, and treble to default, in the middle at level 0. If there are any audio settings, set them all to default, flat. Ensure the fader and balance are centered.
Set the multimeter to AC voltage.
Connect the multimeter's positive lead to the left front positive speaker wire.
Connect the multimeter's negative lead to the left front negative speaker wire.
Download a 1 kHz test tone onto a USB flash drive if installing an amp on highs, or a 40Hz test tone if installing a subwoofer.
Play the test tone and set the volume to 75%.
Take note of the voltage shown on the meter. It should be somewhere in the range of 3-10 volts.

From a factory radio with a factory amplifier:

Disconnect all speakers from the amplifier to prevent damage. If this cannot be done, then this test cannot be performed.
Set the bass, mid, and treble to default, in the middle at level 0. If there are any audio settings, set them all to default, flat. Ensure the fader and balance are centered.
Set the multimeter to AC voltage.
Connect the multimeter's positive lead to the left front positive speaker wire from the factory amplifier.
Connect the multimeter's negative lead to the left front negative speaker wire from the factory amplifier.
Download a 1 kHz test tone to a USB flash drive when installing an amp on the highs, or a 40Hz test tone when installing a subwoofer.
Play the test tone and set the volume to 75%.
Take note of the voltage shown on the meter. It should be somewhere in the range of 3-40 volts. Make sure the LOC or amplifier connected to the factory amp can handle the voltage shown on the meter. Refer to the product manual for input voltage.

From an audio processor or LOC (line out converter):

Note: If any speakers are still playing audio with the RCA jacks unplugged, they will need to be disconnected to avoid being damaged.

All audio settings must be default.
1. On the radio, set the bass, mid, and treble to default, in the middle at level 0. If there are any audio settings, set them all to default, flat. Ensure the fader and balance are centered.
2. On the audio processor or LOC, disable or set any sound effects such as bass boost to zero.
Set the multimeter to AC voltage.
Unplug the left RCA jack from the amplifier. Connect the positive lead from the multimeter to the tip of the RCA. Connect the negative lead from the multimeter to the base of the RCA.
Download a 1 kHz test tone to a USB flash drive if installing an amp on highs, or a 40Hz test tone when installing a subwoofer.
Play the test tone and set the volume to 75%.
Take note of the voltage shown on the meter. It should be somewhere between 1 and 10 volts.

Now that we know the source's output voltage, we can level-match the amp. Use these examples as a reference.
- If the source voltage is 6 volts (ideal), turn the gain dial all the way counterclockwise.
- If the source voltage is 3 volts, set the gain dial exactly in the middle.
- If the source voltage is 0.2 volts, set the gain all the way clockwise.

Note: A voltage this low denotes a problem, and you will most likely experience undesirable noise.