Hmm...wut brand components u got? I know for my Infinity components, u only got 1 choice for the 6.5". Just (+) and (-). But for the tweeters, u got 2 choices for (+). One (+) is the normal one and the other (+) is +3db.
In your case, the (-) has one options. As for the 2 (+), it doesn't hurt to try them out and see how the sound quality is. It's not gonna blow! haha