either way is acceptable. unsure installers use more then one line off the battery . unsure why maybe to prevent confusion ????
DC power in a car in dirty power to begin with. so giving it own power really doesnt make for better sound.thats an old install-tale. proper grounding and adding a stiffening cap will clean up your power alil bit. to achieve quality sound. start investing is good equipment..
you know they say those who cant do! teach
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