Pardon me for sounding like an idiot. But I got this bass like 2 years ago "used" (the guy bought it, returned it two days later without even playing it. His loss, I saved $). Anyways, I've kind of been winging it with the switches. I know what they do, but I don't know what they do... So what do they actually do to the sound? Like I know it when I play it but I'm wondering what it is in technical terms. Confused? I'm sorry, I am too...
the middle switch lets you choose between humbucking mode and "single coil with bass boost" mode. On ones made after the early '80s, I believe, the middle switch lets you choose between series and parallel modes, but the pickups are always humbucking.