Shure Beta 91A Half-Cardioid Condenser Boundary Microphone
The Shure Beta 91A Boundary Microphone is designed for use with kick drums, as well as traditional low end applications including piano. Featuring an updated microphone capsule, integrated preamplifier and XLR connection, for a strong low-end response - specifically tailored for bass frequency applications. The Beta 91A combines superior attack and punch for studio quality sound, even at extremely high sound pressure levels (SPL).
Shure Beta 91A Half-Cardioid Condenser Boundary Microphone Features
- Uniform half-cardioid polar pattern for maximum gain-before-feedback and rejection of off-axis
- 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 â?" select the
- flat response setting for natural sound in most applications or the â??low-mid scoopâ? setting for a
- strong low frequency â??punchâ? with plenty of higher frequency attack.
- Requires no external mounting or accessories for ease of use and storage
- Furnished with zipper pouch
Shure Beta 91A Half-Cardioid Condenser Boundary Microphone Specifications
- Type: Condenser (externally biased)
- Frequency Response: 20 to 20,000 Hz
- Polar Pattern: Half-cardioid (cardioid in hemisphere above mounting surface)
- Impedance: 146 Ω
- Sensitivity (at 1 kHz, open circuit voltage): −48.5 dBV/Pa (3.8 mV) 1 Pascal=94 dB SPL
- Maximum SPL (1 kHz at 1% THD)
- 1000 Ω load: 151 dB
- 2500 Ω load: 155 dB
- Signal-to-Noise Ratio (referenced at 94 dB SPL at 1 kHz): 85.5 dB, S/N ratio is difference between 94 dB SPL and equivalent SPL of self noise, A-weighted
- Dynamic Range (at 1 kHz)
- 1000 Ω load: 121.5 dB
- 2500 Ω load: 125.5 dB
- Common Mode Rejection (20 Hz to 20 kHz): > 55 dB
- Clipping Level (20Hz-20 kHz at 1% THD)
- 1000 Ω load: 7.50 dBV
- 2500 Ω 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 (IEC-61938), 5.6 mA
1 Review Hide Reviews Show Reviews
I brought this mic for a very specific purpose, to capture bass drum attack for aggressive/rowdy music, primarily to save from over-equalizing the primary bass drum microphone - for this purpose it is perfect.
The 1-6" placement recommended didn't work for me, rather - placing the mic inside the bass drum around 1" from the resonant head pointing at the batter did, this had the capsule placed around 1/3rd of the way inside the drum head and gave the mic a reasonably balanced tone (otherwise it was unnaturally subby).
Seems to me to be a very specific use mic, as-in 1-trick pony, hence only 4x stars instead of 5.
As an aside I'm a total fanboy of Shure mics, particularly the KSM series, so, take this review with a pinch of salt.