Suntan Large capacitors (1 Farad+)
Large capacitors are connected to the amplifier much the same way a battery is. This means that the capacitor's positive terminal is connected to the amplifier's positive terminal (which also means that it's connected to the battery's positive terminal). The same is true of the capacitor's negative terminal (the cap's negative terminal is connected to chassis ground with the amplifier's negative ground terminal). Like this...
Large capacitors are used as a sort of electrical shock absorber. As voltage starts to rise, the capacitor will absorb energy which will tend to keep the voltage from rising as quickly as it otherwise would. If the voltage starts to fall, the capacitor's stored energy will flow out of the capacitor to try to keep the voltage up. A capacitor's ability to absorb/release energy from/to external circuits depends on the capacitor's specs (capacitance, ESR, ESL...), the output impedance of the power source (alternator and power wire in this case) and the circuit's input impedance (into the amplifier's power supply).
