I’d like to have bigger ones (14g instead of 20g) to run them all the way to the amp in order to get better sound quality. Is that even necessary?
no its not. and you wont get better sound quality by running bigger wire to door speakers. anyone who tells you that you will, doesnt understand the laws of electricity. speaker signal is ac current. much less loss through resistance than dc current. your whole house is wired with 14ga wire because everything in it runs off ac current. the equipment in your house (fridge, washer, dryer, microwave, etc, converts the ac current to dc current because the motors only run one direction. the amplifiers in my truck are class a/b amplifiers so they are power hungry amps. i run more power to my speakers than most people. all of our sq systems we build run high power and oem wire is just fine. as far as amplifier and subwoofer goes, thats where wire guage matters more. because the entire syste. runs on dc current, theres measurable power loss through resistance. and if you are running a lot of power to a sub, then yes run 14 to it. but not needed for speakers