General Description
The Shure® Beta 27 is a studio-grade, side-address condenser microphone for professional sound reinforcement. Its flat frequency response, low self noise, and superior construction quality provide unerring precision in demanding performance and recording environments. A tight supercardioid pattern ensures high gain before feedback, maximum sound isolation, and consistent off-axis rejection.
Features
- Supercardioid polar pattern targets intended sound source with minimized bleed from off axis sound sources
- 1 inch, externally biased, ultra-thin, 2.5 μm, 24 Karat gold-layered, low mass, Mylar® diaphragm provides superior transient response
- Class A, discrete, transformerless preamplifier for transparency, extremely fast transient response, no crossover distortion, and minimal harmonic and intermodulation distortions
- Premium electronic components and gold-plated internal and external connectors
- Subsonic filter eliminates rumble from mechanical vibration below 17Hz
- Switchable 15dB pad for handling extremely high sound pressure levels (SPLs)
- Three-position low-frequency filter switch reduces unwanted background noise or counteracts proximity effect
- Integrated three-stage "pop" protection grille reduces plosives and other breath noise
- Internal shock mount reduces handling and stand noise
Performance Characteristics
- Low self-noise
- Consistent, highly directional polar response
- Exceptional low-frequency reproduction
- Extremely high SPL handling
- High output level
- Extended frequency response
- No crossover distortion
Avoiding Pickup of Unwanted Sound Sources
A supercardioid microphone has the greatest sound rejection at points 120° toward the rear of the microphone. Place the microphone so that unwanted sound sources, such as monitors and loudspeakers, are at these angles, not directly behind it. To minimize feedback and ensure optimum rejection of unwanted sound, always test microphone placement before a performance.
Stand Adapter
Thread the supplied stand adapter onto a floor or boom stand, then thread the microphone onto the adapter.
NOTE: To reduce low-frequency vibrations transmitted through the stand, use an isolating shock mount. Visit www.shure.com for more information.
Settings
Selecting Low-Frequency Response
A three-position switch on the back of the microphone lets you adjust the low-frequency response. Use the low-frequency filter to reduce wind noise, room noise, or proximity effect.
Flat response. Provides the most natural sound in most applications.
Low frequency cutoff. Provides an 18dB-per-octave cutoff at 80Hz. Helps eliminate floor rumble and low-frequency room noise from heating and air conditioning systems. This setting may also be used to compensate for proximity effect or to reduce low frequencies that make an instrument sound dull or muddy.
Low frequency rolloff. Provides a 6dB-per-octave rolloff filter at 115Hz. Use this to compensate for proximity effect or to reduce low frequencies that could make an instrument sound dull or muddy.
Setting Attenuation
The attenuation switch lets you reduce the signal level without altering the frequency response. This can prevent extremely loud sounds from overloading the microphone.
0dB For "quiet" to "normal" sound levels.
-15dB For use with extremely loud sound sources such as drums, horns, or loud guitar cabinets.
Integral Pop Filter
The microphone grille consists of 3 separate mesh layers that act as an integral pop filter. This helps reduce wind and breath noise. Depending on the performer, an external pop-protection screen or windscreen may be necessary when close-miking vocalists.
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 or XLR-to-TRS.
Specifications
Type
Condenser (externally biased)
Frequency Response
20 to 20,000 Hz
Polar Pattern
Supercardioid
Output Impedance
160 Ω
Sensitivity
(at 1 kHz, open circuit voltage, typical)
-37 dBV/Pa[1] (14.1 mV)
Maximum SPL
(1 kHz at 1% THD)
PAD ON |
1000 Ω load |
148 dB SPL |
2500 Ω load |
154 dB SPL |
PAD OFF |
1000 Ω load |
134 dB SPL |
2500 Ω load |
140 dB SPL |
Signal-To-Noise Ratio
(Ref. 94 dB SPL at 1 kHz)
86 dB[2]
Dynamic Range
(at 1 kHz)
1000 Ω load |
126 dB |
2500 Ω load |
132 dB |
Common Mode Rejection
(10 Hz to 10 kHz)
>50 dB
Clipping Level
(20 Hz to 20 kHz, at 1% THD)
1000 Ω load |
2.0 dBV |
2500 Ω load |
8.5 dBV[3] |
Switch
Attenuator Switch |
0, -15 dB |
Low-Frequency Filter Switch |
Flat, –6 dB/octave below 115 Hz, or –18 dB/octave below 80 Hz |
Self Noise
(typical, equivalent SPL, A-weighted)
8.5 dB SPL-A
Polarity
Positive pressure on diaphragm produces positive voltage on pin 2 with respect to pin 3
Weight
Net
428 g 15 oz.)
Connector
Three-pin professional audio (XLR), male, balanced
Power Requirements
11 to 52 V DC[4]phantom power, 6 mA
[1] 1 Pa=94 dB SPL
[2] S/N ratio is difference between 94 dB SPL and equivalent SPL of self noise, A-weighted
[3] THD of microphone preamplifier when applied input signal is equivalent to cartridge output at specified SPL.
[4] All specifications measured with a 48 Vdc phantom power supply. The microphone operates at lower voltages, but with slightly decreased headroom and sensitivity.