I’m not sure of the correctness, but I see the author adjusting eq in the source, this is from the “BASF LH Extra C90” preset:

> highpass=f=50,lowpass=f=13000

> equalizer=f=500:width_type=q:width=0.8:g=-1.2,equalizer=f=6000:width_type=q:width=0.7:g=-4