The wire neearest to the push button clip is +ve, as far as I can remember.
You can tell the polarity of a speaker with a 1.5v battery.
Just connect it to the speaker & look if it moves out or in when you connect it. If it moves out then the poles are the right way. Then just look at which terminals you connected it to.
So if you do it on the original speakers, then you will know which is +ve & -ve.