Predictions for A(f = 1/10 yr) in various SAMs, obtained by fitting the spectrum in the first 9 frequency bins with γ = 13/3 for multiple realizations of the SMBHB population. The error bars represent the 95% confidence interval for the predictions, and account for the scatter due to cosmic variance. For each model (except for the boosted accretion model HS-nod-SN-high-accr (B+20)), the higher prediction is the extrapolation to infinite SAM resolution, while the lower one is the finite-resolution prediction. The shaded area is the 95% confidence interval for the measurement of A(f = 1/10 yr), fixing γ = 13/3. For HS-nod-SN-high-accr (B+20) we only show the result uncorrected for resolution.