A few days ago, I decided to try to figure out what the specs are for the standard stock radio. I was able to come up with these figures:

• Each individual speaker has a nominal impedance of 4-Ohms(stated on the back of each speaker).
• The front speaker pairs(mids and woofers) are wired in parallel so the stereo sees each set as a 2-Ohm set.
• The power output was measured to be: 15.2W @ 4-Ohms front ch, 26.6W @ 2-Ohms front ch, 17.2W @ 4-Ohm rear ch, ??W @ 2-Ohm rear ch.

I did not test the rear channels for 2-Ohm load. I would like to think that because the fronts are setup for 2-Ohm, the rears should be able to drive 2-ohm loads without risk of amp damage. I think I'll try to see what I can get out of the rears at 2-Ohms without damage to the stereo but I need to figure out a way to monitor the stereo so that I can stop the test before any damage occurs.

 

You can add this info to the sticky at the top of the thread.
(also read it if you haven't already)
How did you measure the wattage?

 

Is there any kind of crossover for the front speakers?

If there is, the head unit will never see the pair as a 2-ohm load, even though they're wired in parallel.

 

I just used the basic power equation and Ohm’s Law to get a quick estimate:
P = I*V = (V/Z)*V
Z was nominal speaker impedance, assumed 4-Ohms at 1kHz
Test signal was 1kHz Sine wave at 0dB
V was RMS voltage across load at full volume

I’m not sure about the crossovers for the front speakers. There are 4 sets of wires coming from the head unit, so if there is a crossover it’ll be a basic LC(probably just a cap) along the wires. I doubt there is a “crossover” but I’ll check. I guess an easy way to check is to do a continuity check on the hot wire. A high-pass(cap) on the midrange wire will cause an open circuit at DC.