Two series of tapes were coated to investigate the effect of switching field distribution (SFD) and intrinsic coercivity (Hci) on audio recording properties. In the first series the concentration of γ-Fe2O3was varied by dilution with α-Fe2O3. The SFD, which increased with the amount of α-Fe2O3present, had a large effect on the linear recording range. Signal loss associated with SFD was separated from demagnetization loss. In the second series γ-Fe2O3was blended with different amounts of cobalt doped γ-Fe2O3in order to vary Hci. The ratio of short wavelength saturated output to sensitivity expressed in volts was proportional to Hci.