Noise and systematic residuals in EE, BB, and EB spectra, for difference maps of the half-mission null test binned by Δℓ=10. Spectra are rescaled to the full mission, and also rescaled to full sky from the unmasked sky fraction f_sky = 0.43 used. Data spectra are represented by thick blue lines, and the average of simulations by thin black lines. The blue band shows one ±σ equivalent of the statistical distribution of the simulations. The linear y-axis scales are adapted to show the full data range on each panel.