When it says it is a 2ohm or 8ohm speaker what that means is each voice coil is 4 ohms.
And unlike the poster above me the correct answer is:
If you wire them in parallel 4(4)/4+4 = 2ohms
If you wire them in series 4ohms + 4 ohms = 8ohms
http://www.bcae1.com/spkrmlti.htm
