import pyfar as pf
magnitude = pf.dsp.filter.low_shelf(
    pf.signals.impulse(2**16), 500, 20, 2)
magnitude = pf.dsp.filter.butterworth(magnitude, 8, 50, 'highpass')
sweep = pf.signals.magnitude_spectrum_weighted_sweep(
    2**16, magnitude, 5000, 1000)
pf.plot.time_freq(sweep)