As the guy with the other Kabinet EQ thread I suppose there’s a list of things to consider here:
Did you turn bass boost on?
Have you dialed in some “sweetening” to get rid of treble?
When you listen through headphones, do you plug them directly into the Kemper or into your DAW?
1 bar of gain more means there need to be different output levels between Kab and headphones or you’re creating some slight distortion in the headphones/DAW.
Could also be that your monitor EQ (which includes the cabinet) has a different EQ setting than your headphone out. Have you tried resetting your settings?
Also make sure “space” is turned off on the headphones when comparing to the Kabinet.
Thanks for the tips to try! I haven't systematically played with: bass boost, sweetening, or comparing monitor EQ vs. headphone EQ.
These seem like very logical things to try, thanks!