Get a 1.5V battery and when you get a connection you'll hear a "click" or "pop" when it's connected & disconnected (DC doesn't make any sound
while it's connected but the cone will be pushed-out or pulled-in depending on polarity). If one wire goes to speaker-A and another goes to speaker-B you won't hear anything so the 1st thing is to identify the speaker pairs.
It also "wouldn't hurt" to temporarily remove the speakers and look at the connections.
As you probably now there is usually a pair of wires for each speaker so I don't know what's going-with 4 wires and 4 speakers. They might be wired together in pairs?
Then you'll need to determine polarity. If they are "out of phase" the bass waves will cancel (and you'll get a "spacy sound") so once you've figured-out the connections try reversing the connections to one speaker and listen to how the sound "blends". If there are other speakers used simultaneously in the same room you'll need to check that the polarity is correct in relation to those too. Or, if you can remove the grill you should see the movement when the battery is connected.
