I'm set to buy a Yorkville XM200, which I think is a fabulous sounding combo for the money. I'm thinking, too, that for very little money I could later pick-up something like an Avatar 210 to fill out my sound. And if I get a 4-ohm cab, I'll be running a total of 2 ohms, which would allow me to use all of the Yorkville's 200 watts, which you can't do with just the amp alone. Seems like most amp and cabinets run at 4 or 8 ohm impedance. Not being an electrician, I'm wondering if there is anything inherently wrong with a 2-ohm rig as long as the amp can handle it (which the Yorkville can).