The primary use of the Beta 91A is kick drums. It can also be used for other low frequency applications including piano. The Beta 91A is a half cardioid condenser boundary microphone. You can expect a strong low end response as it is specifically tailored for bass frequency applications, and superior attack and punch for studio quality sound even at extremely high sound pressure levels (SPL). The Beta 91A features a new and updated microphone capsule. The new capsule will result in a more natural high frequency response than the Beta 91.