Ahha, thanks for that Steve, so you're saying that, let's say you have one speaker called speaker 1 and the other called speaker 2.
You take the negative from speaker 1 and wire it to the amp, then the positive from speaker 1 is wired to the negative of speaker 2. Then finally, the positive of speaker 2 is wired to the other terminal on the amp.
Is this what you call in series?
This would be wiring your two speakers in series across one output of the amp.
Not a good idea. Speakers should never be wired this way (apart from tanoy PA systems)
If you have a 2 channel amp that can be bridged, the amp is switched to bridged mode and the left and right "Black" terminals are joined together, you then connect ONE speaker across Left RED and Right RED.
So as the signal increases the left RED goes more -ve and the right RED goes more +ve. Double the voltage (and higher current output). ie you have balenced power out to the speaker.
Regards,
Carl.