Lighting, whether automotive or residential is sensitive to voltage drop. Power supplies in electronic devices have regulators that compensate for voltage drop in the power supply, before the juice gets to the rest of the audio or other device. That is why you don't see any change in your television when your heat pump starts, but your lights may blink at home. The same process works pretty well in cars.
So, I believe that good quality power cables with clean connections are important. The above picture would not show a good connection. Beyond that, only high power amps that draw lots of current need to have upgraded cables.