does + or - really matter i speakers?

Usually the speaker will have the + for the positive side of it and have - for the negative side of it. Also another way to find out is the negative lead will have a smaller hookup lead than the positive which will have a larger connection lead. Hooking them up backwards will put them out of phase and will sound very crappy.Sound Pressure

You know you have the right amount of pressure when your eyes start to water! Now you've got Juice!

you can keep a d battery avaialble with you in your tool box so that you can find polarity quickly what you do is put the positive side of the battery and the negative to the speaker wires then when you touch the speaker wire to the battery if the speaker moves out then wichever speaker wire is connected to the positive side of the battey is positive on the speaker.if it moves inward then switch the wires untill it moves out and you will know what wire is what on the speaker.

If you run a  speaker with reversed polarity it will not damage it. The speaker will just be out of phase. And to check the polarities just do as mobiletoys2002 said to do.