Kemper Output EQ
Frequencies of the Output EQ
Bass Shelf 150 Hz (steep)
Mid Peak 600 Hz
Treble Shelf 2400 Hz
Presence Shelf 10000 Hz
The Tonestack (EQ in the Stack) is different and softer. There is interaction between the controls, so there are no defined frequencies, that can be announced.
Let me say an important word, as assumptions like on this thread keeps me busy since quite a time. There were about four threads in the last too weeks where I had to disagree to assumptions made by measurements Whenever you try to visualize a sonic behavior in means of scope, waveform display or frequency plot, to derive a deeper interpretation, you are very likely to fail. What you see is rarely what you hear. Trust your ears instead! It requires an immense knowledge to make qualified measurements and assumptions to derive better information by measurements and watching the results by your eyes, that you can simply hear with your ears.
In knowledge thereof, I rarely use scopes or analyzers for my development work, as I have failed to often by interpreting what I saw, even though I probably have the background knowledge needed. Instead I use my ears every day.