all its doing is protecting the power wire... if a 4gauge cable grounds out, it'll blow a 100 amp fuse real quick. If you dont get sufficent power to the amps, they will be struggling to produce sound. Its better to allow the amps more power. In my brothers car, he had the older model 5 channel alpine amp, and we were running an 80 amp fuse, if we ran a 60 the amp would cut out all the time because it wasnt getting enough power.