The Shure BETA 181/BI instrument mic is a Shure BETA RPM181/Pre preamp fitted with a Shure RPM181/BI bidirectional capsule. The RPM181/BI capsule is ideal for mono drum overheads, and dual instrument sound source applications.

The Shure BETA 181 a multipurpose instrument microphone and can be used on a wide variety of applications, including guitars, bass and drums (overheads and snares). It has a small-diaphragm design that provides superior audio with textbook polar responses in a form factor compact enough to get close to the source in the tightest conditions. The BETA 181 has a precision-engineered, side-address design that features an innovative locking ring to provide secure connection between capsule and preamplifier with integrated XLR connections.

There are four different capsules available for the BETA 181 microphone: Cardioid (RPM181/C), Supercardioid (RPM181/S), Bidirectional (RPM181/BI), Omnidirectional (RPM181/BI). This makes the BETA 181 an extremely versatile and cost-effective mic that allows the user to interchange capsules according to the application. (Additional capsules sold separately). It comes with a mic clip, zippered carrying case and windscreen.

This microphone requires phantom power and performs best with a 48 VDC supply (IEC-61938). However, it will operate with slightly decreased headroom and sensitivity with supplies as low as 11 VDC.