Hi Adriano!
It’s not so much a matter of preset, as a matter of what settings. NRSC is 75us pre-emphasis with high frequency roll-off. If you select 75us pre-emph, you can use the Transition Width and Transition Slope to adjust the high frequency filter shape.
Pre-emphasis on AM is not as rigid as on FM — every receiver is different, and many have low pass filters with the cutoff so low that pre-emphasis barely makes a difference anyway. So, it’s just a matter of adjusting for taste.
You can tweak the low-end by using the Bass slider! If you turn Bass Shape up, it will also affect the lower midrange.
Best regards,
//Leif