Shure BETA91A

Shure Beta 91A – half-cardioid condenser boundary microphone, built for miking a kick drum from the inside as well as piano. The boundary design, with an integrated preamp and a full-size XLR connector, removes the need for an external stand - the mic lies flat on a surface inside the kick drum shell, cutting cable clutter when several drum microphones go up at once. The 20 Hz to 20,000 Hz frequency response is shaped for low-frequency work, giving a clear attack while keeping a solid bass foundation. Phantom power in the 11-52V range lets the mic run off a typical preamp or digital console without extra adapters.

Extreme SPL handling inside the kick drum

A maximum SPL rating of 155 dB at a 2,500 Ω load lets the mic sit right next to the beater and resonant head without risking capsule overload, even under a very hard pedal strike. Self-noise at 29.5 dBA - lower than the earlier Beta 91 - keeps the signal clean during quieter passages or studio overdubs that need extra dynamic headroom.

A contour switch that shapes attack without console EQ

A two-position contour switch on the underside lets you choose between a flat response and a "low-mid scoop" setting that cuts around 400 Hz by 7 dB, bringing out attack and higher frequencies without reaching for EQ at the FOH console. That speeds up soundcheck when drum kits change between acts and there isn't always time to dial in EQ for each setup individually.

KEY FEATURES

• Half-cardioid condenser boundary microphone
• Integrated preamp and full-size XLR connector, no external stand needed
• Maximum SPL up to 155 dB
• Low self-noise: 29.5 dBA
• Two-position contour switch: flat / low-mid scoop
• Rugged housing with a metal protective grille, pouch included

TECHNICAL SPECIFICATIONS

• Transducer type: electret condenser, boundary design
• Polar pattern: half-cardioid
• Frequency response: 20 Hz - 20,000 Hz
• Sensitivity: 3.8 mV/Pa
• Maximum SPL: 155 dB (at 2,500 Ω load)
• Self-noise: 29.5 dBA
• Power: 11-52V phantom power
• Connector: XLR (3-pin)
• Included: zippered carrying pouch