Shure
Shure Beta 181
Ultra-compact side-address small-diaphragm electret condenser instrument mic: an XLR preamp with interchangeable cardioid, supercardioid, omni and bidirectional capsules
Power Phantom, 11-52 V DC (IEC-61938); best at 48 V.
- Type
- Condenser (electret)
- Pattern
- Switchable, 4
- Sensitivity
- −46.5 dBV/Pa
- Among 204 condensers: more output than 16%
- Among 311 mics: more output than 41%
- Self-noise
- 20.5 dB(A)
- Among 258 condensers: quieter than 22%
- Among 272 mics: quieter than 21%
- Max SPL
- 149 dB SPL
- Among 277 condensers: takes louder sound than 90%
- Among 343 mics: takes louder sound than 89%
- Rated range
- 20 – 20k Hz
- Released
- 2010
vs 75 side-address condensers
More output than 4% of 75 side-address condensers.
Each stripe is one side-address condenser with a published sensitivity, and each bar counts them; further right means more output. This mic is in blue.
vs 99 side-address condensers
Quieter than 4% of 99 side-address condensers.
Each stripe is one side-address condenser with a published self-noise, and each bar counts them; further right means quieter. This mic is in blue.
vs 107 side-address condensers
Takes louder sound than 92% of 107 side-address condensers.
Each stripe is one side-address condenser with a published max SPL, and each bar counts them; further right means it takes louder sound. This mic is in blue.
Proximity effect: the bass it gains up close
From the spec sheet, p. 2.
"Beta 181/C (Cardioid)", "Frequency Response"; relative dB. Distance, room and smoothing 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, p. 2.
"Beta 181/C (Cardioid)", "Polar Pattern"; two circles (250 Hz to 1 kHz, 2500 Hz to 10 kHz), 0° at the bottom, 5 dB per ring. Distance not stated.
In practice
All specs
| From the user guide | ||
|---|---|---|
| Capsule | small diaphragm, interchangeable capsules on a compact XLR preamp, locked by a knurled ringGeneral description and "Changing Capsules" (p. 5). | p. 3 |
| Sensitivity | −46.5 dBV/Pa (4.7 mV/Pa)cardioid; open circuit voltage, 1 kHz, typical; also −49.5 dBV/Pa, supercardioid; also −52 dBV/Pa, omni; also −51 dBV/Pa, bidirectional. "–46.5 dBV/Pa (4.7 mV)", supercardioid "(3.4 mV)", omni "(2.5 mV)", bidirectional "(2.8 mV)". The 2015 sheet gives no sensitivity. | p. 6 |
| Self-noise | 20.5 dB(A)cardioid; equivalent SPL, A-weighted, typical; also 22.5 dB(A), supercardioid; also 23.5 dB(A), omni; also 23 dB(A), bidirectional | p. 7 |
| Max SPL | 149 dB SPLcardioid; 1 kHz, 1% THD, 1000 ohm load; also 151.5 dB SPL, cardioid, 2500 ohm load; also 152 dB SPL, supercardioid, 1000 ohm; also 154.5 dB SPL, supercardioid, 2500 ohm; also 154 dB SPL, omni, 1000 ohm; also 157 dB SPL, omni, 2500 ohm; also 153.5 dB SPL, bidirectional, 1000 ohm; also 156 dB SPL, bidirectional, 2500 ohm. THD of the preamplifier when fed the cartridge output at that SPL (footnote 2). Pages 6-7; the sheet gives the 1000 ohm figures. | p. 6 |
| Signal-to-noise ratio | 73.5 dBcardioid; re 94 dB SPL, A-weighted; also 71.5 dB, supercardioid; also 70.5 dB, omni; also 71 dB, bidirectional. The 2015 sheet gives 72.5 dB for the supercardioid; 94 - 22.5 = 71.5, so the guide is right. | p. 7 |
| Dynamic range | 128.5 dBcardioid; 1 kHz, 1000 ohm load; also 131 dB, cardioid, 2500 ohm; also 129.5 dB, supercardioid, 1000 ohm; also 132 dB, supercardioid, 2500 ohm; also 130.5 dB, omni, 1000 ohm; also 133.5 dB, omni, 2500 ohm; also 130.5 dB, bidirectional, 1000 ohm; also 133 dB, bidirectional, 2500 ohm | |
| Output impedance | 110 ohmoutput impedance. "110 Ω". | p. 6 |
| Rated load impedance | 1000 ohmrecommended minimum. "Shure recommends a minimum input load impedance of 1000 Ω." | |
| Rated frequency range | 20 Hz to 20 kHz | |
| Powering | phantom, 11-52 V DC (IEC-61938); best at 48 V"11–52 V DC phantom power (IEC-61938)", p. 8; all specs measured at 48 V. | p. 8 |
| Current draw | 2.4 mAmaximum. "2.4 mA, maximum". The 2015 sheet says "1.2 mA". | |
| Weight | 145 g"145 g (5.1 oz.)". | |
| Dimensions | 124.46 × 34.54 × 20.32 mmDimension drawing (Beta 181/C): length 124.46 mm (4.90 in.), capsule head 34.54 mm (1.36 in.), body 20.32 mm (0.80 in.) across. | |
| Supplied accessories | A57F stand adapter (mic clip); A181C carrying case (holds up to four capsules); A181WS foam windscreen | p. 9 |
| Clipping level | 10.5 dBV (2500 ohm load), 7.5 dBV (1000 ohm load), 1 kHz, 1% THD | p. 7 |
| Common mode rejection | ≥55 dB, 20 Hz to 20 kHz | p. 8 |
| Polarity | Positive pressure on diaphragm produces positive voltage on pin 2 with respect to pin 3; sound from the back of the bidirectional capsule is out of polarity | |
| Performance characteristics | Transformer output; no crossover distortion | p. 3 |
| Grille | Hardened steel mesh | |
| Replacement parts | RPM181/C, RPM181/S, RPM181/O, RPM181/BI capsules; RPM181/PRE XLR preamp | p. 10 |
| Optional accessories | A75M universal mount; A53M isolation mount/swivel adapter; C25E cable | |
| RejectionShure | Off-axis null at 180° (cardioid), 120° (supercardioid), 90° (bidirectional) | p. 5 |
| ApplicationsShure | Cardioid: drum overheads, piano, acoustic instruments, M/S with a /BI; supercardioid: snare, close-miking; omni: room, string ensembles, mono overhead; bidirectional: Blumlein pair, mono overhead, between two sources | p. 4 |
| From the spec sheet | ||
| Connector | XLR-3 male, on the preamp"compact XLR preamplifier with integrated XLR connections". | p. 1 |
| Models | Beta 181/C, /S, /O, /BI (each one capsule and one preamp); BETA181/KIT with all four capsules | |
| From the Recording Hacks page | ||
| Released | 2010 | |
Documents
- Beta 181 Ultra-Compact Side-Address Instrument Microphone, Product Specifications
- BETA181 Ultra-Compact Side-Address Microphone, user guideVersion 4.0, 2024-B
- Shure Beta 181 | RecordingHacks.com
Copies kept by Mic Archive (manufacturers move and drop their documents). Each is © Shure, unchanged, with its original address.