I'm just getting ready to build a couple of 2x12 cabinets that I want to run in stereo out of my power amp that is powering my Eleven Rack. I am having a bit of trouble wrapping my head around the impedance of the cabinet compared to the power amp.

I understand that if I put in 8 ohm speakers in the cabinet and wire them in series I have a 16 ohm cabinet, and if I run them in parallel I would have a 4 ohm cabinet. But when it comes to the power amp, if I run two 16 ohm cabinets in stereo, should I be looking at the wattage specs for the 16 ohm per channel or the 8 ohm per channel? From what I was reading somewhere if you run two cabinets in stereo it halves the ohms or something. It just didn't make sense, so I thought I'd try and see if I could get a more concrete answer.

And for example's sake, lets say the power amp is a Rocktron Velocity 300 and the cabinets are loaded with 2 V30's @ 60W apiece.

Thanks in advance for the clarification. Hopefully I phrased my question in a way that is understandable.
Elitists and Hypocrites
if it is a true stereo amp that means each side/section is a separate amp. So you would use the 16 ohms setting for each side of the amp.
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If you give exact details on what Power amp you're using, and maybe the speakers that you plan on using too, then I think people can help you.
"Air created the greenness. And once you've got something, that leads to otherness." - Karl Pilkington.
Most likely the Rocktron Velocity 300 and one of each of the Eminence Cannabis Rex and Screamin Eagle in each cabinet.
Elitists and Hypocrites