I'm looking to get an extension cab for my Ampeg BA500. It is a 4 ohm rig as it sits, and can handle down to 2 ohm. I would like to stay with an Ampeg cab, but they are a bit hard to come by in a 4 ohm rating. If I use an 8 ohm cab, the overall ohm rating would be 2.7. What are the downsides of mixing different ohm ratings? I've found a good deal locally on an Ampeg 8 ohm 4x10 cab, but if it is not going to sound good or be damaging to the amp or speakers, I'll keep searching. Thanks and Happy New Year!