Brent Butterworth

Audio and video often seem like nothing more than numbers games. So much is specified in some kind of figure: 7.1 channels, 200 watts, 800 lumens, 90 decibels. Sure, it's simplistic and pandering, but on the whole it's good. If Match.com could deliver this level of precision, I'd be a much happier man.

Like panthers or hamsters or bats, video projectors do the bulk of their business in the dark. But darkness makes most humans uncomfortable, which may be why front projection has never made it into the mainstream - in order to get a good picture, you have to turn most, and preferably all, of the lights off.

The "Bass Management Boot Camp" article about subwoofer setup that I wrote for the November S+V inspired an in-turn inspiring e-mail from reader Bruce Erwin. Bruce recalled his days setting up sound systems when he'd use a 1.5-volt battery to test subwoofer phase. If the sub and main speakers were in phase, he'd hear a single thump when he connected the battery to the wires leading to the sub's terminals. If they were out of phase, he'd hear a double thump.

That's with passive subwoofers, though. Almost all of today's subs have built-in amps, so this method wouldn't quite work with them. Still, it got me wondering if I could come up with a simpler phase check than the ones I suggested in the article, which required either measurement or careful listening. My e-mail convo with Bruce gave me some ideas and, ultimately, a method that's simpler than my original. And all you need to do it is a piece of free software and a meter you've either already got or can get for nothing.