So I have been researching this for a while and have yet to find the 100% answer. I understand that speakers and chips pull the amount of power they need, but what about amplifiers and power supplies.
So lets say I have a 750 watt amp and a 700 watt sub. I have my volume turned to moderate level and the speaker needs 350 watts. Is my amp still pulling 750 watts from my electrical system or only the 350 my speakers requested plus the efficiency and amp requirements(lets say 350+50 into heat + 50 to drive the amp =450)?
Also for power supplies, they have to have the power required at all times. If I hook a 125w power supply to my carputer, is it always burning 125w or just what the computer draws?
My reasons for asking are I am at the threshold for major electrical upgrades and if the amps and power supply are pulling less then max and only whats needed, its not an issue. However, if they pull max I will need to get the electrical done before I do the install.