Stereo and Speakers
 

Folks, I just changed out the CDR220 with an Alpine unit as well as the dash (4" Kickers) and door (5 1/4" Kickers) speakers. The sound is now pretty crappy, with almost no bass. Is it the amp I need to change? I'm also hearing I should have purchased sub-woofer type speakers for my doors instead of "all range?"

The factory Haes 4x40 amp has a low-pass filter that only feeds the bass band to the doors. Your new Alpine may very well have a more powerful built in amp. Easiest and cheapest option given how far you've already gone is to wire the door speakers directly to your head unit's speaker level outputs and bypass the factory amp altogether.