High acoustic noise and vibration is one of the main drawbacks, which has limited the wide application of switched reluctance machine (SRM), especially when it is noise and vibration sensitive. Therefore, many studies have been carried out to reduce the acoustic noise and vibration of SRM. One attractive and effective method is the active vibration cancellation (AVC) proposed by Wu and Pollock, which is easy to realize without increasing any hardware. This paper presents a simple analytical method for predicting the maximum reduction levels of vibration and noise by AVC, compared with the conventional excitation. Its predicted results are then verified by experiments on a prototype 6/4 SRM.