Shure's Beata 91A microphone is usually used for kick drums. The Shure microphone is used for low frequency applications, such as piano. The Beta 91A is a half-cardioid capacitor interface microphone. Because the microphone is specially designed for bass frequency applications you get a strong low-end response. The Beta 91A has a new and updated microphone capsule that gives a more natural high frequency response than the Beta 91.