The Shure Beta 91™ is specifically designed for kick drums and other bass instruments.

The Beta 91 combines superior "attack" and "punch" for studio quality sound, even at the extremely high sound pressure levels encountered inside a kick drum. Its boundary effect design produces a strong, solid low-end response that has been specifically tailored for heavy bass applications. 

The microphone's cardioid pattern provides outstanding gain-before-feedback and excellent rejection of unwanted sound, making the Beta 91 ideal for live concert applications. The low profile design of the Beta 91 eliminates the need for external mounting hardware - just throw it in your kick drum and play. 

Dynamic Range

(20 Hz to 20 kHz, less than 1% THD, 2.5 kilohm load)

125 dB (max SPL minus A-weighted noise)

Output Noise

35 dB SPL (typical), A-weighted

Signal-to-Noise Ratio

59 dB re 94 dB SPL

Output Impedance

150 ohms (actual)

Polarity

Positive pressure on diaphragm produces positive voltage on pin 2 with respect to pin 3

Power

Phantom Power: 48 Vdc +/- 4 Vdc (IEC-268-15/DIN 45 596), positive pins 2 and 3

Electromagnetic Hum Pickup

-7.5 dB equivalent SPL in 1 mOe field (60 Hz)

Cable

4.6 m (15 ft) heavy-duty, two-conductor shielded, TA4F to TA3F connectors

Case

Matte-black , painted, die-cast, zinc-alloy case with matte-black steel grille

Dimensions

95 mm x 129 mm x 19 mm (3.75 in. x 5.08 in. x 0.75 in.)

Net Weight

382 grams (13.5 oz) less cable