Shure BETA91A Boundary Bass Drum Microphone

Features of the Shure BETA91A Boundary Bass Drum Microphone :

• Uniform half-cardioid polar pattern for maximum gain-before-feedback and rejection of off-axis sound
• Precision-engineered low-profile design features integrated preamplifier and XLR connector to maximize setup efficiency while minimizing stage clutter
• Frequency response tailored for kick drum/low frequency applications with a wide dynamic range for use in high SPL environments
• Two-position contour switch to maximize attack and clarity depending on application: select the flat response setting for natural sound in most applications or the “low-mid scoop” setting for a strong low frequency “punch” with plenty of higher frequency attack
• Requires no external mounting or accessories for ease of use and storage
• Furnished with zipper pouch

Specifications:

Clipping Level (20Hz-20 kHz at 1% THD)
1000 Ohm load: 7.50 dBV, 2500 Ohm load: 12.5 dBV
THD of microphone preamplifier when applied input signal is equivalent to cartridge output at specified SPL
Self Noise (typical, equivalent SPL, A-weighted)
29.5 dB SPL-A
Polarity
Positive pressure on diaphragm produces positive voltage on pin 2 with respect to pin 3
Weight
Net: 470 g (16.6 oz.)
Frequency Contour Switch
7 dB of attenuation centered at 400 kHz
Connector
Three-pin professional audio (XLR), male, balanced
Power Requirements
11-52 Vdc phantom power, 5.6 mA
Type
Electret Condenser
Frequency Response
20 to 20,000 Hz
Polar Pattern
Half-cardioid (cardioid in hemisphere above mounting surface)
Impedance
146 Ohms
Sensitivity (at 1 kHz, open circuit voltage)
-48.5 dBV/Pa (3.8mV)
1 Pascal=94 dB SPL
Maximum SPL (1 kHz at 1% THD)
1000 Ohm load: 151 dB, 2500 Ohm load: 155 dB
Signal-to-Noise Ratio (referenced at 94 dB SPL at 1 kHz)
64 dB
S/N ratio is difference between 94 dB SPL and equivalent SPL of self noise, A-weighted
Dynamic Range (at 1 kHz)
1000 Ohm load: 121.5 dB
2500 Ohm load: 125.5 dB
Common Mode Rejection (20 Hz to 20 kHz)
> 55 dB