Shure Beta 91A Half-Cardioid Condenser Kick Drum Microphone

The Shure Beta 91A is a premier boundary condenser microphone designed specifically for kick drums and low-frequency applications. Combining an integrated preamplifier with a tailored frequency response, the Beta 91A delivers superior studio-quality attack and “punch” in high-SPL environments, both on stage and in the studio.

Engineered for High-Impact Sound

The Beta 91A features a half-cardioid polar pattern (cardioid in the hemisphere above the mounting surface) to ensure maximum gain-before-feedback and rejection of unwanted off-axis noise. Its low-profile design eliminates the need for external mounting hardware, allowing it to sit securely inside a kick drum or on a piano soundboard.

• Two-Position Contour Switch: A toggle on the bottom of the microphone allows for a “flat” response for natural sound or a “low-mid scoop” setting that enhances attack and clarity by attenuating frequencies centered at 400 Hz.

• Integrated Preamplifier: Unlike older boundary mics, the Beta 91A includes an integrated XLR connector, reducing stage clutter and simplifying setup without the need for an external preamp box.

• Wide Dynamic Range: Capable of handling sound pressure levels (SPL) up to 155 dB, this microphone captures the heaviest hitters without distortion.

• Rugged Construction: Built with a steel grille and die-cast metal housing to withstand the rigors of professional touring.

Primary Applications

Kick Drums

The Beta 91A is the industry standard for internal kick drum miking. Placed on a pillow or the shell’s interior, it captures the “click” and definition of the beater. It is frequently paired with a Shure Beta 52A placed at the sound hole to capture a blend of high-end attack and low-end “thump.”

Grand Pianos

For live reinforcement or studio recording, the Beta 91A can be mounted to the underside of a piano lid. The boundary design provides excellent isolation and a well-balanced, bright tone even when the lid is closed.

Technical Specifications

Frequently Asked Questions

Does the Beta 91A require phantom power?

Yes. As an electret condenser microphone, the Beta 91A requires 11 to 52 V DC phantom power to operate. It performs optimally with a standard 48 V supply.

How does the Beta 91A differ from the original Beta 91?

The Beta 91A features a redesigned capsule and an integrated preamplifier. While the original required a proprietary cable and external preamp, the 91A connects directly via a standard XLR cable.

Can this microphone be used for vocals?

While technically possible, the Beta 91A is specifically tailored for low-frequency instruments. For vocals, a dedicated vocal mic like the SM58 is recommended.