Get the original speaker in hand and determine which color wire (green or blue) was connected to which terminal (right or left when looking at magnet with terminals up). If those terminals are marked with "+" and "-" you have your answer. If they are not marked, take a 9 volt battery and touch the batt terms to the terminals of the old speaker (small term on 9v batt is "+").. You may have to use jumper wire for this. Note which direction the speaker cone moves (in toward magnet or out away from magnet). Now touch the batt to the terms of the new speaker. Note which way the cone moves. This exercise should tell you if the speakers have the same polarity terminals in the same positions. If they do, connect the wires to the same terminals on the new speaker as they were connected to the old. If "+" and "-" are reversed from old speakers to new speakers, you will have to reverse how the wires connect to the new speaker. Don't hold the 9v battery to any speaker terminals for any length of time. Short (1-2 seconds) won't hurt, but any longer could heat up the wire of the voice coil and may cause problems.