Bass output is achieved through speakers called subwoofers; these speakers play dedicated lower bass frequencies and are designed specifically for that function. One of the causes of poor-performing subwoofers is lack of power. If a high-powered subwoofer is not getting the power it needs, then it will produce a weaker sound. A capacitor helps supply power to the subwoofer's amplifier during times of peak performance. The capacitor connects to the battery and stores power for the amplifier so that when high power consumption occurs (playing bass-heavy music loudly), the amplifier and subwoofer receive enough power.
Disconnect the amplifier's power cables from the car's battery.
Remove the power cables connected to the amplifier. These are the cables that are attached the car battery and also the "Power" connectors on the amplifier. Remember which cable is positive and which is negative.
Connect those power cables to the "Power In" ports on the capacitor. There will be two ports, a "+" or "Positive" and a "-" or "Negative." Make sure the right cables (positive and negative) go to their matching connectors.
Cut the same type of wire that was used to run the power from the battery to the amplifier. A much shorter length will be needed. Cut two lengths of this wire between 3 to 4 feet. Select one wire to be the positive wire and one to be the negative wire.
Connect one of the wires to the "Power Output" negative terminal on the capacitor. Connect the other end of the wire to the negative power input on the amplifier (where the negative wire was removed from earlier).
Connect the other wires to the "Power Output" positive terminal on the capacitor. Connect the other end of the wire to the positive power input on the amplifier (where the positive wire was removed from earlier).
Connect the stereo's power wires back to the car's battery. Start the vehicle and wait for approximately 10 minutes to charge the capacitor. Do not play the stereo during this time. After 10 minutes test the stereo.