Shure
Shure Beta 91A
Boundary condenser, half-cardioid (kick drum, piano)
Power Phantom, 11–52 V DC (IEC-61938).
- Type
- Condenser (electret)
- Pattern
- Half-cardioid
- Sensitivity
- −48.5 dBV/Pa
- Among 311 mics: more output than 37%
- Self-noise
- 29.5 dB(A)
- Among 272 mics: quieter than 4%
- Max SPL
- 155 dB SPL
- Among 343 mics: takes louder sound than 95%
- Rated range
- 20 – 20k Hz
- Released
- 2010
vs 204 condensers
More output than 11% of 204 condensers.
Each stripe is one condenser with a published sensitivity, and each bar counts them; further right means more output. This mic is in blue.
vs 258 condensers
Quieter than 5% of 258 condensers.
Each stripe is one condenser with a published self-noise, and each bar counts them; further right means quieter. This mic is in blue.
vs 277 condensers
Takes louder sound than 97% of 277 condensers.
Each stripe is one condenser with a published max SPL, and each bar counts them; further right means it takes louder sound. This mic is in blue.
Instruments sources recommend it for most
3 of 5; all under Recommended for.
Proximity effect: the bass it gains up close
From the spec sheet (Recording Hacks copy), p. 1.
On a boundary (the mic lies on a surface). Measured at 61 cm (2 ft), as printed on the graph. Anechoic or not, smoothing and typical-vs-individual are not stated.
Dashed: outside the rated range, or simulated (other angles and distances). Hover or tap the graphs for values.
Polar pattern
From the spec sheet (Recording Hacks copy), p. 1.
Full circle as printed, 0° at the bottom. Measuring conditions not stated. The sheet calls the pattern half-cardioid: cardioid in the hemisphere above the mounting surface.
In practice
All specs
| From the spec sheet (Recording Hacks copy) | ||
|---|---|---|
| Sensitivity | −48.5 dBV/Pa (3.8 mV/Pa)open circuit voltage, 1 kHz, typical | p. 2 |
| Self-noise | 29.5 dB(A)equivalent SPL, A-weighted, typical | |
| Max SPL | 155 dB SPL1 kHz, 1% THD, 2500 ohm load; also 151 dB SPL, 1 kHz, 1% THD, 1000 ohm load. THD of the preamplifier when its input equals the cartridge output at that SPL (footnote 2). | |
| Signal-to-noise ratio | 64.5 dBre 94 dB SPL, A-weighted | |
| Dynamic range | 125.5 dB1 kHz, 2500 ohm load; also 121.5 dB, 1 kHz, 1000 ohm load | |
| Output impedance | 146 ohm1 kHz | |
| Rated load impedance | 1000 ohmminimum recommended | |
| Rated frequency range | 20 Hz to 20 kHzTolerance not stated. The printed graph starts at 50 Hz. | |
| Powering | phantom, 11–52 V DC (IEC-61938)Specs measured at 48 V; works down to 11 V with less headroom and sensitivity. | |
| Current draw | 5.4 mA | |
| Switches | contour: flat, low-mid scoopPage 2: "7 dB of attenuation centered at 400 kHz". The graph shows the dip at about 400 Hz, so "kHz" is a typo. | p. 1 |
| Connector | XLR-3 male"Three-pin professional audio (XLR), male, balanced"; built into the mic body. | p. 2 |
| Weight | 470 g | |
| Dimensions | 139.1 × 95.11 × 20.3 mmLength × width × height, from the dimension drawing. | |
| Supplied accessories | Zippered carrying bag (95A2314) | |
| Clipping Level20 Hz to 20 kHz, 1% THD | 2500 Ω load: 12.5 dBV; 1000 Ω load: 7.5 dBV | |
| Common Mode Rejection20 Hz to 200 kHz | ≥55 dB | |
| Frequency Contour Switch | 7 dB of attenuation centered at 400 kHz | |
| Polarity | Positive pressure on diaphragm produces positive voltage on pin 2 with respect to pin 3 | |
| Optional Accessories | 7.6 m (25 ft.) Cable, C25E | |
| Replacement Parts | Cardioid Cartridge, RPM98A/C | |
| Certification | CE; European EMC Directive 2004/108/EC; EN55103-1:1996 and EN55103-2:1996 (E1, E2) | |
| From the user guide (Recording Hacks copy) | ||
| Placementkick drum | Inside drum, on a pillow or other cushioning surface, 25 to 152 mm (1 to 6 in.) from beater head | p. 3 |
| Placementpiano | Underside of lid over lower treble strings; or vertically on the inside of the frame near the apex of the curved wall | |
| From the Recording Hacks page | ||
| Released | 2010 | |
Documents
- Beta 91A specification sheet
- Beta 91A user guide
- BETA91A half-cardioid condenser microphone, user guideversion 3.1, 2021-B
- Shure Beta 91A | RecordingHacks.com
Copies kept by Mic Archive (manufacturers move and drop their documents). Each is © Shure, unchanged, with its original address.
Recommended for
By recording guides, engineers and mic makers, for this mic or an earlier version of it.