I just bought the Powerworks PW100 speaker to try out with my Kemper. I have a Yamaha dxr10 as well. I have to say for less than half the price of the Dxr10 the Powerworks holds it's own very well. It's a very small speaker also. Loud as hell!
I recommend people look into this speaker as a very cheap alternate to the Yamaha. I paid $190 for mine new. They have (4) 4" speakers and a horn tweeter.