Shure Beta 91A Specification Sheet

BETA 91A Instrument Microphone

Model Beta 91A Wired Microphones

Specication Sheet

Applications and Placement

Half-cardioid Polar Pattern

Boundary microphones pick up
sound in a cardioid polar pattern in
the hemisphere above the mounting
surface. Keep sound sources within
the 60 degree range above this
surface.

60

General Description

The Shure Beta 91A is designed for use with kick drums, piano and other
traditional low frequency applications. An updated microphone capsule is
tailored for bass-heavy environments to produce a powerful low frequency
response, and a new design integrates the preamplifier and XLR connec­tion for easy setup and minimal stage clutter. The Beta 91A combines
superior attack and punch for studio-quality sound, even at extremely high
sound pressure levels (SPLs).

Features

• Premier live performance microphone with Shure quality, ruggedness,
and reliability

• Uniform half-cardioid polar pattern (in the hemisphere above mounting
surface) for maximum gain before feedback and rejection of off-axis
sound

• Tailored frequency response for kick drums and bass-heavy
instruments

• Wide dynamic range for use in high SPL environments

• Two-position contour switch enhances attack and clarity

• Integrated preamp and XLR connector reduce stage clutter and provide

a quick, secure setup

• Low profile design requires no external mounting hardware

• Steel grille and die-cast metal construction resist wear and abuse

Performance Characteristics

• Exceptional low-frequency reproduction

• Extremely high SPL handling

• High output level

• No crossover distortion

120°

90°

60°

+20

+10

0

dB

–10

-20

20 200001000 1000050 100

180°

150°

30°

61 cm (2 ft.) from sound source

EQ

–20 dB

–15 dB

–10 dB

–5 dB

150°

30°

0

250 Hz

500 Hz

1000 Hz

120°

60°

120°

90°

90°

60°

98765432 98765432

150°

180°

150°

120°

–20 dB

–15 dB

–10 dB

–5 dB

30°

0

6300 Hz

10000 Hz

90°

60°

30°

Hz

Contour Switch

A two-position switch on the bottom of the microphone lets you selectively
filter the low-mid frequency response without additional tools. Use this fil­ter to enhance the attack and clarity of bass-heavy instruments.

Flat response: Provides the most

EQ

EQ

Mounting the Microphone

For long-term installation, mount the Beta 91A to a surface using the
mounting holes on the bottom of microphone.

natural sound in most applications.

Low-Mid Scoop: This setting tai­lors the microphone’s frequency
response to provide a strong ‘punch’
in the low frequencies, and plenty of
attack in the higher frequencies.

TL1073 (Rev. 1) Printed in U.S.A.
©2010 Shure Incorporated

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

Cartridge Type Electret Condenser

Polar Pattern Half-cardioid (cardioid in hemisphere

Frequency Response 20 to 20,000 Hz

Output Impedance

@ 1 kHz

Sensitivity

open circuit voltage, @ 1 kHz,
typical

Maximum SPL

1 kHz at 1% THD

Signal-to-Noise Ratio

[2]

[3]

Dynamic Range

@ 1 kHz

Clipping Level

20 Hz to 20 kHz, 1% THD

Self Noise

equivalent SPL, A-weighted,
typical

Common Mode Rejection

20 Hz to 200 kHz

Frequency Contour Switch 7 dB of attenuation centered at 400 kHz

Connector Three-pin professional audio (XLR),

Polarity Positive pressure on diaphragm pro-

Power Requirements 11–52 V DC

Net Weight 470 g (16.6 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.

above mounting surface)

146Ω

–48.5 dBV/Pa

[1]

(3.8 mV)

2500Ωload 155 dB
1000Ωload 151 dB

64.5 dB

2500Ωload 125.5 dB
1000Ωload 121.5 dB

2500Ωload 12.5 dBV
1000Ωload 7.5 dBV

29.5 dB SPL-A

≥55dB

male, balanced

duces positive voltage on pin 2 with
respect to pin 3

[4]

phantom power

(IEC-61938), 5.4 mA

Accessories and Parts

Furnished Accessories

Zippered Carrying Bag 95A2314

Optional Accessories

7.6 m (25 ft.) Cable C25E

Replacement Parts

Cardioid Cartridge RPM98A/C

)

.

n

i

4

7

mm (3.

1

1

,

5

9

20,3 mm (0.8 in.)

13

9,1

m

m (

5

.48 in

.)

Dimensions

CERTIFICATION

Eligible to bear CE Marking. Conforms to European EMC Directive
2004/108/EC. Meets Harmonized Standards EN55103-1:1996
and EN55103-2:1996, for residential (E1) and light industrial (E2)
environments.

The Declaration of Conformity can be obtained from:

Authorized European representative:
Shure Europe GmbH
Headquarters Europe, Middle East & Africa
Department: EMEA Approval
Wannenacker Str. 28
D-74078 Heilbronn, Germany
Phone: [phone]
Fax: [phone]
Email: [e-mail]

www.shure.com

United States, Canada, Latin
America, Caribbean:

Shure Incorporated
5800 West Touhy Avenue
Niles, IL 60714-4608 USA

Phone: [phone]
Fax: [phone] (USA)
Fax: [phone]
Email: [e-mail]

©2010 Shure Incorporated

Europe, Middle East, Africa:

Shure Europe GmbH
Wannenäckestr. 28,
74078 Heilbronn, Germany

Phone: [phone]
Fax: [phone]
Email: [e-mail]

Asia, Pacific:

Shure Asia Limited

22/F, 625 King’s Road
North Point, Island East

Hong Kong

Phone: [phone]
Fax: [phone]
Email: [e-mail]