I have for years been using a genz benz streamliner 600 as my main gigging amp. It has been trouble free and sounds great with an aguilar db112. Almost all the time I find one cab enough, I last played with 2 cabs about 6 months ago. Yesterday I was trying some things out at home and I noticed whilst the amp sounded fat and wonderful with 1 cab (running 8ohm) when I connected 2 cabs (running 4ohms) it sounded thin and horrible. Each cab individually sounded great and I'm sure 6 months ago running 2 cabs was glorious. Any ideas? I tested the leads, not them.