Wow I just found this thread and it's my exact same experience. I just put two Kemper Kones in my Victory 2X12 and it's so disappointing just thin and tinny. I've done cab on cab off and all the different speaker choices as well as the bass booster. But it's not even close to a good tone. Has anyone ever figured out the solution to this? I feel like I'm one button push away from great tone. But as it is it's no good.
Sounds great through a regular guitar cab though with regular speakers.