i got 2x pioneer 50 watt rms 220 peekspeaker in front, and im getting pioneer 6x9 rev 80 watt rms, 330 peak, i have a lightning amp with 50 x 2 rms and 450 peak, should i get a bugger amp for the back speaker or use the old amp for the back speaker and the cd player output for the front speaker? thx