i am thinking about changing all my speakers in the car to something that will make it louder then the factory speakers. is it necessary to add another amp and also any suggestions on a setup of speakers i should do?

 

i changed all my factory 6.5 and i sounds really good, i just bout 6 6.5in. and i took the stock subwoofer and left the hole and added 2 12" subwoofer.

 

and what i noticed, if you play audio files that are 256kbps the sound is louder and the factory amp does not clip off,

 

ELS or Base system?

Jeff