Example of the resulting stacked spectra in bins of log(L[N II]) = 0.5 at a radius of 1 r_eff within the galaxy NGC 628, with all spectra shifted to their rest wavelength based on their Hα velocity. Individual H II region spectra are shown in color, the mean stacked spectrum is shown in black, and the fit is shown in red. This wavelength range focuses on the [N II]λ5755 line, marked with a blue dashed line. The luminosity bin, number of individual H II regions included, and resulting S/N of the fit are shown in the upper left corner of each plot.