JasenGibson

DC will read about 80% or so of what AC impedance will read. Also, that 8 Ohms figure they gave you is an average. The actual impedance varies dynamically according to what frequency the driver is producing. If you want to get an accurate measurement of the driver's actual impedance curve, you'd have to measure it using the PC while playing a frequency sweep to see the whole range. Software that can do this (such as DATS) comes with a special USB cable with alligator clips. You generally don't need to bother with this level of detail unless you start getting into more advanced building, designing custom crossovers and the like.