A phase compensation circuit, for use with an FM reception system, includes a delay circuit and a control circuit. The main pole has a top surface including a first inclined portion and a flat portion. A crossover network separates the left channel and the right channel into low frequency content, midrange frequency content, and high frequency content. Accordingly, the cooking apparatus can be easily designed. A non-authentication balance stored in memory is updated to an amount of money equal to or smaller than the authentication balance. The filter may be adapted to decrease the computational complexity of the resulting calculations, making the filter amenable to use in power sensitive applications and in those situations where the available processor’s performance is relatively limited.