Virial broadening estimators based on Hβ, with several corrections applied to the HE sample. Top square panel: FWHM Hβ_BC (blue (Pop. A) and red (Pop. B)) with error bars, symmetrized FWHM Hβ (symm, black), and FWHM Hβ corrected according to spectral type (st, aquamarine and dark orange for Pop. A and B respectively) versus FWHM of the full Hβ profile. The gray line traces the correction (corr) following the relation of Sulentic et al. (2006a) reported in Sect. 4. Middle panels: ratios of FWHM after various corrections vs. full profile FWHM. Panels from top show: BC/symm, BC/st, BC/corr, symm/ st, corr/st. Average values, standard deviation and normalized are reported in the upper-right corner of the panels. Bottom square panel: BC, spectral type st and reverberation corrected (corr, open symbols) FWHM values vs. symmetrized FWHM.