Electrical Questions / Wiring

This may or may not be necessary. and it may be "audio hype" which is rampant

There might be some consideration. Do you have an understanding of A.C. circuits, impedance, and such? "In basic" here's the idea

When you are transferring very large amounts of power (high wattage stereo) using very low load impedances (such as 4 and 8 ohm speakers) this starts to require large amounts of instantaneous current, in order to maintain the power. Also, trying to operate amplifier devices at "only" 12V makes this worse, as the devices themselves are subject to large resistance losses, known commonly as "I squared R" which is a reference to the power formula, P in watts = I (current draw in amps squared) X the resistance. This concept holds true, whether tail lights, you house system, or the huge transmission lines across country.