So i just installed one jl 12w3 and a memphis 500.1 amp in my 1st gen gs. I used 4ga wire and everything works fine. Before i added the sub i kinda thought that my battery was weak. Now with the sub i feel that my car does not perform as well as it did. Pick up seems weaker, and the blinker indicator seems to blink slower. (lol) I dunno if its my imagination but i dont think so. Could this be because of a weak battery or a weak ground or something? Should I upgrade to a different battery or just try a new one? Any advise?

 

When your car is running.. the alternator is providing the juice, and your battery is a load on the alternator.. (it is being charged).. I don't think the car's performance would suffer from a 500W rms Amp. I was running a little more power than that in my LS400 and had no problems. My headlights dimmed sometimes to the beat, but thats about it.

Try disconnecting your amp for a day and see if you notice a REAL change. Then try messing around with your ground.

 

if you upgrade your battery, look into batcap.