Audio Systems: Car Amp/Speakers, car amp, watt amp

Question
Recently I replaced my rear speakers in my car with Pioneer 350 watt 6x9 speakers.  I also had a new 600 watt amp installed to power the 6x9s.  However, my two front speakers now hardly produce any sound at all.  Is it because my CD player is sending all it's power to the amp that's powering my rear 6x9s?  Even when I adjust the fader and put all the music to my front speakers, it is still hardly audible (very very quiet).  Do you have any suggestions, or what should I do to get the sound quality back in my front speakers?  Thanks!

Answer
Do to the power of the amp you installed, you dont have to turn the volume up as loud to make the 6x9's loud. Thus making the fronts seem not as loud. They still play the same as before. I would suggest an amp for the fronts. Your cd player cant send power to the rear.
Tim