I already upgraded my headunit to the Pioneer AVH 4200 and front speakers to Alpine coaxial 6 1/2. I kinda want it to be stronger, but I don't want to spend too much money. Should I:
1) Upgrade rear speakers, add sub, and pick up 2 amps (4 channel, mono amp)
2) Get 4 channel amp and subwoofer. (use 2 channels for fronts and 2 to power the sub)
or another suggestion.