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 Feature Details Type Electret Condenser Polar Pattern Half-cardioid (Unidirectional) Frequency Response 20 Hz to 20,000 Hz Output Impedance 150 Ohms Sensitivity -48.5 dBV/Pa (3.8 mV) Max SPL (2500 Ohm Load) 155 dB Power Requirements 11-52 V DC phantom power (5.4 mA) Weight 470 grams (16.6 oz) Connector Three-pin professional audio (XLR) 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.