Carson's Rule is an approximate method to calculate the "minimum" bandwidth in a frequency modulated satellite signal so a high-fidelity, sharp picture will be delivered. While reducing the bandwidth below that recommended by Carson's Rule is a common practice and does result in a higher video S/N ratio, this is at the expense of streaking in fast moving scenes and overall picture sharpness. A concurrent loss of audio fidelity also can occur. The greater the number of subcarriers, the greater the Carson's bandwidth required. This calculation of minimum bandwidth does not include the smaller effect of the deviation of a satellite signal caused by the energy dispersal waveform.