Upgraded from factory to Alpine CDE-9846, but 2loud!, what happened? speaker+heatunit mismatch? Options

[JediFonger]

i've got a '99 Toyota Celica GT. i hated not being able to play mp3 CDRW's/CDR's, so i upgraded haphazardly because i was also installing a new alarm system yesterday.

http://www.alpine-usa.com/en/products/prod...?model=CDE-9846
^got that installed yesterday. i didn't have a chance to demo it much last night when i picked up the vehicle... but this morning, i tried playing stuff. the unit plays all the way upto 20+ in terms of volume... but anytime i approach 4 or 5, all of my speakers are distorted. it's 16w RMS, what the heck is going on? i didn't upgrade anything else, ONLY headunit. it's just 2much power and overbearing. the speakers are distorting like crazy if i play too loudly. i can't get a clean sound, loud sound, just muddy sounds. what could be at fault?

i don't have $ to upgrade to new speakers... i just wanted the capability of mp3 playback, which it does.