Shure Beta 91

Frequency response shaped specifically for kick drums and other instruments
Wide dynamic range for use in high SPL environments
Low-profile design requires no external mounting hardware
Detachable cable for easy storage
Legendary Shure quality, ruggedness, and reliability

Interchangeable replacement cartridges:

RPM108 : Cardioid
RPM110 : Supercardioid

Type
Cardioid condenser (electret bias)

Frequency Response
20 to 20,000 Hz

(measured at 304.8 mm [1 ft] from a spherical sound source, free field conditions)

Polar Pattern
Half-cardioid (cardioid in hemisphere above mounting surface), uniform with frequency, symmetrical around axis.

Output Level (at 1,000 Hz)
Open Circuit Voltage: -59 dBV/Pa* (1.1 mV) typical
*1 Pa = 94 dB SPL

Maximum SPL
(20 Hz to 20 kHz, less than 1% THD)
2.5 kilohm load: 160 dB
1 kilohm load: 156 dB

Preamplifier Output Clipping Level
(20 Hz to 20 kHz, less than 1% THD*)
2.5 kilohm load: 6 dBV (2.0 V)
1 kilohm load: 2 dBV (1.26 V)
*THD of the microphone preamplifier when applied input signal is equivalent to the cartridge output at specified SPL.

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