SHURE BETA 181 Ultra Compact Side Address Microphone User Guide
- June 14, 2024
- Shure
Table of Contents
BETA181 Ultra-Compact Side-Address Microphone
BETA181
Ultra-Compact Side-Address Microphone
General Description
The Shure Beta 181 is an ultra-compact, side-address, condenser microphone, designed for discreet placement in live and studio environments. Featuring interchangeable cardioid, supercardioid, omnidirectional and bidirectional capsules for superior versatility, the small diaphragm of the Beta 181 provides superior audio with consistent, “textbook” polar responses in a form factor small enough to get close to the source in the tightest conditions.
Features
- Premier live performance microphone with Shure quality, ruggedness, and reliability
- Compact preamp attaches to four interchangeable capsules
- Wide dynamic range for use in high SPL environments
- Side-address form allows for discreet positioning in tight performance and recording settings
- Innovative locking ring provides a secure connection between capsule and preamp
- Hardened steel mesh grille resists denting, wear, and abuse
- Compact design, under 12 cm (5 in.), reduces stage clutter
- Furnished with stand adapter and carrying case
Variations
- Beta 181/C Cardioid Microphone
- Beta 181/S Supercardioid Microphone
- Beta 181/O Omnidirectional Microphone
- Beta 181/BI Bidirectional Microphone
Performance Characteristics
- Exceptional low-frequency reproduction
- Extremely high SPL handling
- High output level
- No crossover distortion
- Transformer output
Applications
Positioning the Microphone
The front of the microphone is marked by the Shure logo. Position this side
toward the sound source.
General Rules for Use
- Do not cover any part of the microphone grille with your hand, as this will adversely affect microphone performance.
- Aim the microphone toward the desired sound source (such as the talker, singer, or instrument) and away from unwanted sources.
- Place the microphone as close as practical to the desired sound source.
- Work close to the microphone for extra bass response.
- Use only one microphone to pick up a single sound source.
- For better gain before feedback, use fewer microphones.
- Keep the distance between microphones at least three times the distance from each microphone to its source (“three to one rule”).
- Place microphones as far as possible from reflective surfaces.
- Add a windscreen when using the microphone outdoors.
- Avoid excessive handling to minimize pickup of mechanical noise and vibration.
Applications and Placement
The following table lists the most common applications and placement
techniques. Keep in mind that microphone technique is largely a matter of
personal taste; there is no one “correct” microphone position.
Cardioid | Supercardioid | Omnidirectional | Bidirectional |
---|
Drum overheads
Piano
Acoustic instruments
Pair with a Beta 181/BI for M/S stereo technique| Close-miking in performance
settings
Snare drum
Acoustic instruments| Room and ambient pickup Mono drum overhead
String ensembles| Use a pair of Beta 181/BI for Blumlein stereo technique Mono
drum overhead
Dual sound sources, such as between tom-toms or acoustic instruments
As with all bidirectional microphones, sounds picked up from the back will be
out of polarity with the source. Those from the front are in polarity with the
source.
Avoiding Pickup of Unwanted Sound Sources
Directional microphones are most sensitive to sounds arriving on axis and
reject at angles depending upon the polar pattern.
The following chart shows the rejection angles of each microphone. In live
performance or recording settings, align monitors, P.A. loudspeakers, and
unwanted sound sources at these angles.
To minimize feedback and ensure optimum rejection of unwanted sound, always
test microphone placement before a performance.
Cardioid | Supercardioid | Bidirectional |
---|---|---|
![SHURE BETA 181 Ultra Compact Side Address Microphone - |
Supercardioid](https://manuals.plus/wp-content/uploads/2023/11/SHURE-BETA-181
-Ultra-Compact-Side-Address-Microphone-Supercardioid.jpg)|
Off-axis null points at 180 degrees| Off-axis null points at 120 degrees| Off-
axis null points at 90 degrees
Changing Capsules
Follow these steps to change Beta 181 capsules:
- Turn off phantom power and disconnect from equipment.
- Unscrew the capsule’s knurled ring to detach the preamp.
- Slide the alignment key on the bottom of the capsule into the groove on the preamp to ensure that the Shure logo displays the front of the microphone.
- Tighten the knurled ring to securely reconnect the microphone.
NOTE: Before each use, make sure the capsule is tightly secured on the microphone, as vibration and accidental hits with drumsticks may loosen it, resulting in signal loss.
Load Impedance
Maximum SPL capability, output clipping level, and dynamic range vary with the input load impedance of the preamplifier to which you connect the microphone. Shure recommends a minimum input load impedance of 1000 Ω. Most modern microphone preamplifiers meet this requirement. Higher impedance results in better performance for these specifications.
Power Requirements
This microphone requires phantom power and performs best with a 48 Vdc supply
(IEC-61938). However, it will operate with slightly decreased headroom and
sensitivity with supplies as low as 11 Vdc.
Most modern mixers provide phantom power. You must use a balanced microphone
cable: XLR-to-XLR.
Specifications
Type
Electret Condenser
Polar Pattern
181/C: | Cardioid |
---|---|
181/S: | Supercardioid |
181/O: | Omnidirectional |
181/BI: | Bidirectional |
Frequency Response 20 to 20,000 Hz
Output Impedance 110 Ω
Sensitivity open circuit voltage, @ 1 kHz, typical
Cardioid | –46.5 dBV/Pa[1] (4.7 mV) |
---|---|
Supercardioid | –49.5 dBV/Pa[1] (3.4 mV) |
Omnidirectional | –52.0 dBV/Pa[1] (2.5 mV) |
Bidirectional | –51.0 dBV/Pa[1] (2.8 mV) |
Maximum SPL 1 kHz at 1% THD[2]
2500 Ω load | Cardioid | 151.5 dB SPL |
---|---|---|
Supercardioid | 154.5 dB SPL | |
Omnidirectional | 157.0 dB SPL | |
Bidirectional | 156.0 dB SPL | |
1000 Ω load | Cardioid | 149.0 dB SPL |
Supercardioid | 152.0 dB SPL | |
Omnidirectional | 154.0 dB SPL | |
Bidirectional | 153.5 dB SPL |
Signal-to-Noise Ratio[3]
Cardioid | 73.5 dB |
---|---|
Supercardioid | 71.5 dB |
Omnidirectional | 70.5 dB |
Bidirectional | 71.0 dB |
Dynamic Range
2500 Ω load | Cardioid | 131.0 dB |
---|---|---|
Supercardioid | 132.0 dB | |
Omnidirectional | 133.5 dB | |
Bidirectional | 133.0 dB | |
1000 Ω load | Cardioid | 128.5 dB |
Supercardioid | 129.5 dB | |
Omnidirectional | 130.5 dB | |
Bidirectional | 130.5 dB |
Clipping Level
@ 1 kHz, 1% THD
2500 Ω load | 10.5 dBV |
---|---|
1000 Ω load | 7.5 dBV |
Self Noise
equivalent SPL, A-weighted, typical
Cardioid | 20.5 dB SPL-A |
---|---|
Supercardioid | 22.5 dB SPL-A |
Omnidirectional | 23.5 dB SPL-A |
Bidirectional | 23.0 dB SPL-A |
Common Mode Rejection
20 to 20,000 kHz
≥55 dB
Polarity
Positive pressure on diaphragm produces positive voltage on pin 2 with respect
to pin 3
Power Requirements
11–52 V DC[4] phantom power (IEC-61938)
2.4 mA, maximum
Weight
145 g (5.1 oz.)
[1] 1 Pa=94 dB SPL
[2]THD of microphone preamplifier when applied input signal level is
equivalent to cartridge output at specified SPL
[3]S/N ratio is the difference between 94 dB SPL and equivalent SPL of self
noise, A-weighted
[4]All specifications measured with a 48 Vdc phantom power supply. The
microphone operates at lower voltages, but with slightly decreased headroom
and sensitivity.
Accessories
Furnished Accessories
Microphone Clip for AMS26, BETA181, KSM137, KSM141, MX412, MX418, MX412S,
MX418S, MX412SE, MX418SE, SM62, SM63, SM63L, SM63LB, SM81, VP64, VP64A, VP64AL
and standard microphone stands| A57F
---|---
Foam case assembly for BETA181| A181C
Foam Windscreen for BETA181| A181WS
Optional Accessories
BETA181 Cardioid Capsule | RPM181/C |
---|---|
BETA181 Supercardioid Capsule | RPM181/S |
BETA181 Bidirectional Capsule | RPM181/BI |
BETA181 Omnidirectional Capsule | RPM181/O |
BETA181 Preamplifier | RPM181/PRE |
Universal Microphone Mount with Large and Small Clip Adapters and Universal
Threaded Adapter Post| A75M
Isolation Mount/Swivel Adapter for KSM109, KSM137, KSM141, SM63, SM81, SM94
and VP64| A53M
25 foot (7.5m) Triple-Flex® Microphone XLR Cable with Switchcraft connectors|
C25E
Certifications
CE Notice
Hereby, Shure Incorporated declares that this product with CE Marking has been
determined to be in compliance with European Union requirements.
The full text of the EU declaration of conformity is available at the
following site: https://www.shure.com/en-EU/support/declarations-of-
conformity.
UKCA Notice
Hereby, Shure Incorporated declares that this product with UKCA Marking has
been determined to be in compliance with UKCA requirements.
The full text of the UK declaration of conformity is available at the
following site: https://www.shure.com/en-GB/support/declarations-of-
conformity.
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