Max Alternator Output

Fountainhead

Capacitors are used in audio amps for
A: Bulk Caps (2200uF to 3300uF and up) Removing ripple from the high frequency switching supply that changes +12VDC to +/- up to 80VDC. (In parallel with high dissipation factor ceramics for the high frequency ripple).
B. They are used for storage for low frequency impulse power/peak demand. See 1 above.
C. They are used as AC coupling devices that block DC from stage to stage.
D. They are used as "Decoupling" devices to clean DC voltage so that active amplifier components have a clean power supply.

Scientifically I can't say that I support using large Farad value caps on the voltage rail of the +12V since the Battery can supply up to 350 Amps at cranking time on the car, so if the Alternator and the Battery can't handle the current load of the amplifier, then it sounds as if other have correctly recommended upgrading the charging/Alternator and the 12V reservoir/Battery.

I'm all for the smart marketing of the Farad add on caps, someone is making money and that's good old fashioned Capitalism at it's finest.