4 ohm or 8 ohm?

[Scott Reed]

You may also want to consider a stereo (or bi-amp) head. They may give you little more flexibility in tone and configurations. With my WT-500, I can run 2 x 4ohm cabs in stereo mode and maintain a 4ohm load (on each channel). If I put it in Bridged Mono Mode, it puts out 600 watts/8 ohms and it "requires" an 8 ohm load. If I ever intended to run more then 1 cabinet, I would have gotten the WT-800.

From my experience (horror story)... Just because a company issues a 2 ohm spec, that doesn't mean you should actually try to run it at 2 ohms for an length of time =)