I took off the door trim panel and the dash tweeter tonight. I was somewhat disgusted to find the wire running to each speaker is very thin (18-20 gauge?). Also disappointing was the entry point of the door wiring. It's very high up on the door pillar which would make replacement of the speaker wire difficult without removing the dash assembly.

On a positive note the tweeter did appear to be of moderate quality - not simply a very small paper driver. It had three terminals on it, with the speaker input wires going to two of the wires and an orange component (stamped 1L8 824) going between the third terminal and one of the speaker input wires.

With the speakers in place, I did continuity checks between all the terminals. Between some of the terminals it was 0 ohm resistance, others it was 4 ohm resistance, and between the legs of the orange component it was around 7 ohms resistance. My best guess based on my tinkering around tonight is that each speaker is a 4 ohm speaker, they may be wired in parallel as some have suggested, and there is a 7 ohm resistor inline to boost the resistance (to keep the head unit happy... two 4 ohm speakers wired in parallel without additional resistance inline would present the head unit with a 2 ohm load).

At this point it appears:
- Running thicker wire to the door speakers would not be an easy undertaking at all.
- The tweeters can easily be unplugged. Perhaps this is an easy way to put full-range speakers in the door and get rid of the poor imaging provided by the stock tweeters?
- I could just replace the door speakers with aftermarket ones, leaving the tweeters connected, but there's no saying how that'd sound or if the resistor(?) on the tweeter could handle the power of an amplifier.

I think I'll probably leave well enough alone and live with the factory door speakers and tweeters, powered by my head unit. I wish Honda didn't make it so impossible to replace the factory sound system with superior aftermarket components.

Any other advice??

-Dan