In electromagnetic exploration using broadband sensors and systems, joint recording of B and dB/dt data derived from the same physical sensor allows for a greater number of "signal" bits that lie above sensor noise. Optimum choice of a crossover frequency where the gains of B and dB/dt data match may double the number of useable bits. Field data confirms general expectations that B mode of operation is good at low frequencies, dB/dt operation good for high frequencies, but that both can be collected from the same ARMIT sensor.