If no one has rewired it, then it's a two driver cab at 16 ohm, rated at twice the power handling of a single driver. If someone has rewired it to bypass the missing driver, then they might have simply jumpered the missing one, for a 5 1/3 ohm cab rated to handle 1.5 times the power of a single driver. Or they might have three in parallel for 2 2/3 ohm rated at thrice the power of a single driver. Or all in series for 24 ohm. O'm having trouble figuring how to get a 12 ohm cab.