The gain knobs are expressly there to moderate the channel input volume. It’s why you have channel level meters. You load and play a track, find a loud(er) part and look at the levels. They should be steady for all the greens (usually up to and including 0dB) and the first and perhaps second light higher should be flashing at the peaks. Too much, then you turn gain down until you reach that state.
There is nothing “natural” about gain settings since every track has different dynamic and recording level.
So, it’s one of your “jobs” as a DJ to do level management, every track.
Mind you, there might still be some setting within Traktor you can use to bring the incoming volume down somehow. And things like auto-gain and limiting might be relevant too. But I am too rusty on Traktor to comment on this with any certainty.
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