BETA 91A Kick Drum (Boundary Type) Condenser MicThe Beta 91A is optimised for kick drums, as well as traditional low end applications including piano. It uses a half cardioid condenser boundary microphone with an integrated XLR preamplifier that is tailored for a strong low end response. It has a two position contour switch for optimised sound signature depending on application. The primary use of the Beta 91A is kick drums. It can also be used for other low frequency applications including piano.