Audio Systems: speaker selection 2 or 4 ohms/expanding from 4 to 6 speaker channels, sony xploid, pioneer truck

Question
1993 Chevy Z-71 4x4 pick-up. I currently have a new Sony Xploid CD player with removable face, it's rated at (52)watts x 4 channels. The ohms rating is not known. I have 3 sets of speakers in my possesion I would like to install in this truck. First a set of Pioneer 4" woofer/tweeter speakers rated at (100)watts max at 2 ohms. These are tobe installed in the dash. The second set are Sony's 4"x6" speakers rated at (120)watts max at 4 ohms, I'd like these in the doors or the pillars behind the vehicles occupents heads. And last but not least, I have a set of Pioneer truck boxes with either 6" or 8" woofers, and tweets built in. There rated at (200)watts max at 4 ohms.The boxes will go behind the seats.
O.K. here's my first question.#1 Can the speakers I have with 2 and 4 ohm ratings be used together? #2 Can I run three sets of speakers (6 channels) insted of the original (4 channels) with the my Sony Xploid CD player? If so, #3 Will an amp be needed to push any of these speakers? #4 If an amp isn't needed what about a crossover?

Answer
Michael,
If you add more speakers to your Sony stereo you will cause to amps in it to burn out. Check the output impedance of the stereo. If the output impedance is rated at 8 ohms try to keep the speaker load/impedance at 8 ohms! With the 120 and 200 watt speakers you will need an external amp to drive the speakers. If the Sony stereo has RCA outputs you can use those to send audio to the new amp. If no RCA outputs are on the Sony you can install a high level(speaker) to low level (RCA outputs). Pick out a four channel amp that has built in adjustable cross over circuits with a power output of about 100 watts. You can use channel 1 & 2 for the two rear speakers Sony 4X6 and channel 3 & 4 for the woofers.

TOM,
T&D ELECTRONICS
tdeser@zoominternet.net