Thursday, September 16, 2004

Hacking car audio

I have a lot of digital music, and I wanted to listen to it in the car. The first thing I tried was burning CDs. This car player, however, had trouble reading those CDs. I have one CD in there made up of the best of three other CDs I own, and it works after a tense pause. All other CDs would follow that tense pause with the CD player spitting the disc out.

So, I got a portable digital music player, and I sought a way to play it in the car. I have a cassette adapter, but not a cassette player. The FM transmitter I got didn't work. So, I started thinking about cruder ways. I consulted with my brother-in-law who's a manager at Radio Shack.

I can't plug into the radio directly because it doesn't have any kind of auxiliary input. Radios these days are sometimes set up for a trunk CD changer, but mine isn't.

Can I wire my headphone output straight into the speakers, bypassing the radio? No, I was reminded, the power from the headphones isn't enough to drive the speakers. I'd need an amplifier.

Maybe I could get a long headphone extension cord for the FM transmitter so I could put it in the back window, closer to the antenna. Frankly, the FM transmitter would have been too weak even then, I'm sure. Even if that were not the case, I wouldn't want to get in the back seat to change the batteries every ten hours of use or to diddle with the channel setting when I wander into some territory electromagnetically hostile to the channel I'm using. The good news is the thing turns itself on and off automatically according to whether it has input.

Then I got a really wild idea. I'll extend the antenna into the car! I'll have the car's antenna in the front seat, wrapped around the FM transmitter. The signal will have to jump only millimeters of air. That might actually have worked except, as previously noted, the FM transmitter seems to simply stink even at very close range.

I talked to a car audio shop, and they nearly sold me a better FM transmitter. This one wires right into the antenna so that nothing goes through the air (as such, it's actually an FM modulator, not transmitter). They said sound degradation is 7% with this thing, and it's strong enough to overpower interference from all but the very closest radio station (i.e., within a mile). I would have been sold except that it can only transmit on one of two stations, selected with a switch at install time.

Finally, I spent another $200 to get a new radio, one with an aux input. The guys at the car audio shop even ran RCA connectors between the seats so I can have my player handy as I drive. It sounds great. I can actually hear the difference between tracks encoded at different qualities.

And that, folks, is what I like to hear.

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