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This is going to sound like a stupid question, and it's analog audio but I figure you guys might know, so I'll admit I'm stupid and ask anyway:

We have a video baby monitor that came with a standard RCA-mini male to split 2-channel RCA male plugs. To hook up to a TV if you want something larger than the built-in LCD on the monitor unit. Of course one channel is audio, one video, there are only two contact bands on the mini-plug, unlike the three contact bands on, say, an iPod video-out cable. It's mono of course because hearing your toddler yell in stereo is no better than in mono. On the RCA male jacks, video is yellow, audio is white.

Because I am cheap and we never connect the baby monitor to the TV, I am using this cable to connect my Mac headphone-out to my nearby stereo, instead of buying an RCA-mini audio splitter cable. My question is, how do I know which channel is which? Usually, of course, the white plug is left, the red is right. But I have white and yellow. I get audio on both channels, but how do I know I'm connected to the stereo receiver in phase?

Is it safe to assume that the left channel on the two-band mini connector is going to the white-plugged wire, and the right channel is going to the yellow, the one intended for video? I know, I know, I don't have to buy Monster cable and can get a properly color-coded cable for like $10. But why not use what I have, if I can? Is there any way that does not involve sophisticated audio analysis to prove that the left channel coming out of my Powerbook is ending up on the white-plugged wire on the cable, the right on the yellow plug? (I'm also half-deaf so the chance of me hearing the channel difference is pretty slim; which of course will cause you to make the point that if I can't hear the difference, why do I care? But I care, I care.)

System prefs -> Audio settings, set balance all the way to the left. Play something while only the white plug is plugged in to your reciever. See which speaker the sound is coming from (I'm assuming you have stereo speakers, otherwise it could get tricky).

Oh, btw, the headphone out-jack is also known as an 1/8" TRS (not mini-RCA).

It's Dolby Surround, but I can set it to 2-channel stereo mode only, which shuts off the signal to center and rear channels; so it will stereo speakers when I test.

That's such a cool test. Thanks for the idea. Easy, too. I shall let you know what's what.

Not mini-RCA, uh? Well, hmm, mini-RCA is just so, you know, *marketable*. ;-)

That was it, left on white (intended for mono audio), right on yellow (intended for video). But now I know for sure, I've saved a little money, and I'm all happy about it! Thanks.