Zoom H4 quality audio

hey everyone,

I bought a zoom H4n to record my sets with the xone 92, I use the mix 2 output (TRS) to the Zoom input (TRS), but the quality isn't great, it's correct but not great at all, I put the parameters for -6db and I use the 48 KHz record frequency. I don't really know what can I do...I really notice the difference between what I hear in the headphone while I mix and when I hear the record