John,

I took advantage of yesterday's snow day in the northeast here and installed a sub into my C70. I'm so much happier with the system now. Here's what I did.

I installed a second amp, wired for 1 X 300, mono to a 10" subwoofer. To wire this in, I spliced the rear speaker wires, under the rear deck, before they reach the white connectors. I connected those "spliced sections" with solder and ran speaker wire from there to a line ouput converter to step the powered output from the stock Alpine down to preamp levels. This converter also acts as an adapter from speaker level inputs to RCA outputs so it plugged nicely into my amp.

I also intalled a capacitor in hopes that it would eliminate headlight dimming (more on that later). It also provides enough power to my aftermarket amp, when it needs it to generate those power sucking, low signals. I installed the capacitor so that it's wired to the battery and ground, and the aftermarket amp is wired to it directly.

The remote power on wire, I ran from the Yellow and Violet ACC wire in the back of the stereo. I cut a section of the insulation of that wire (so I didn't have to sever it) and connected the remote power on wire to the exposed wire and wrapped some electrical wire around the connection to secure it.
I snaked this wire along the driver's side, under the kick panel and under the plastic panels along the footboard. Also I ran the power cable to the rear in the same way, but to the front - through the existing tube in the fire wall, to the engine compartment. I removed the bottom rear seat cushion to send the wires to the back and hide them along the rear seatbelt holder.

So when all was said and done, I flipped on the switch and WOW! The system suddenly turns into an animal! I had to adjust the gain on the line output converter and on the amp to tone down the bass. After that, everything sounds so smooth and even. Pro Logic works just fine as well as the center channel. I'm so much happier with the system now. However, there's a problem. I went for a ride last night to test out the new sounds without disturbing my neighbors and my headlights still dim when the bass punches. I looked this up on Crutchfield's tech support page and they recommend upgrading the altenator. UGH! How much will this cost now?!?!? I don't have much a budget cuz I'm buying new wheels and tires. Catch is, if I don't upgrade the alternator, it is likely to burn out within a year.

So all in all, it was a lot easier than I thought. The sound is worth it. I put in a 10" sealed sub and that is more than enough - I wouldn't want to add any more. I got free CPR on my way to work today! But the headlight dimming issue bothers me. So if you can handle replacing hundreds of LEDs, this should take you just a few hours.

Steve