When i play my favorite profiles with the kemper over a 4x12 marshall cab it sounds awesome, but when i play them over studiomonitors with the cab simulation on, it sounds much thinner and powerless.
Do you have any tips for me? Would be great!
I tried to make it sound better with the cab settings and it really gets better but not near as good as it sounds with a "real" cab.
This is a common issue if you're used to a guitar cabinet. Guitar cabinets roll off a lot of high end and low end on a tone, and reproduce the sound in a different way than a studio monitor, which is designed to be flat.
Another big factor is that profiles are basically the sound of a miced up a guitar cabinet, rather than a guitar cabinet. As such, there is a marked difference in comparison to playing directly through a cabinet, which is an amp in the room sound.
You'll just have to acclimatise yourself to hearing the FRFR (full range flat response) sound as opposed to an AITR (amp in the room sound).
Rest assured the FRFR sound is the best way to judge a tone that is going on a recording, since you are mainly interested in getting a miced up guitar tone. It is also important to use this FRFR sound when playing live, as you can send your main outputs to the FOH and it will sound killer, just like a miced up cab on stage.