Shure KSM27 User manual

User Guide
27B3138 (CD)
E2003, Shure Incorporated Printed in U.S.A.

1
SHURE INCORPORATED
KSM27 CARDIOID CONDENSER MICROPHONE
If you have any questions that are not answered in this booklet, please contact Shure
Applications Engineering at 847-866-2525, Monday through Friday, from 8:00 am to
4:30 pm, CST. In Europe, call 49-7131-72140. Our web address is www.shure.com.
Thank you for selecting the KSM27
Over 75 years of audio experience has contributed to making the KSM27
one of the finest microphones available.

2
KSM27 BACKKSM27 FRONT
15 dB
attenuator
Low-frequency
response switch
FIGURE 1. KSM27 FRONT AND BACK
GENERAL DESCRIPTION
The ShureRKSM27 is a side-address condenser microphone with a cardioid polar
pattern. Designed for studio use but rugged enough for live applications, the KSM27
has an externally biased 1-inch diaphragm, extremely low self-noise, and an
extended frequency response specially tailored for vocal tracking and instrument
recording.
FEATURES
SCardioid polar pattern – the most commonly used pattern for both studio and
live applications
S1 inch, externally biased, ultra-thin, 2.5 µm, 24 Karat gold-layered, low
mass, MylarRdiaphragm provides superior transient response
SClass A, discrete, transformerless preamplifier for transparency, extremely fast
transient response and no crossover distortion, while minimizing harmonic and
intermodulation distortions
SPremium electronic components and gold-plated internal and external
connectors
SSubsonic filter eliminates rumble from mechanical vibration below 17 Hz
SSwitchable 15 dB pad for handling extremely high sound pressure levels (SPLs)
S3-position switchable low-frequency filter helps reduce unwanted back-
ground noise or counteract proximity effect
SIntegrated three-stage “pop” protection grille reduces plosives and other
breath noise
SInternal shock mount reduces handling and stand noise

3
PERFORMANCE CHARACTERISTICS
SExtended frequency response
SLow self noise
SExceptional low-frequency reproduction
SHigh output level
SHigh input SPL capability
SNo crossover distortion
SExtremely uniform polar response
SSuperior common mode rejection and suppression of radio frequency
interference
APPLICATIONS
The KSM27 produces superior results in any application requiring a high quality
microphone. Typical applications include:
SVoice and vocals
SClose-miking of acoustic instruments such as piano, guitar, violins, drums,
and percussion
SElectric guitar amplifiers
SBrass and woodwind instruments
SLow-frequency instruments such as double bass and kick drum
SOverhead miking for drums or percussion
SOrchestras, choirs, wind ensembles
SRoom ambience pick-up (guitar amplifier or drums)
NOTE: Sound quality is strongly affected by microphone location and room
acoustics. To acheive the best overall sound for a particular application, it may be
necessary to experiment with microphone placement and various room treatments.
OPERATING THE KSM27
Mounting
Use the shock mount to secure the KSM27 to a floor or boom stand by threading the
shock mount onto the microphone stand and inserting/threading the microphone into
the shock mount.
Power
The KSM27 requires phantom power and performs optimally with a 48 Vdc supply
(IEC-268-15/DIN45 596). However, it will operate with slightly decreased headroom
and sensitivity with supplies as low as 11 Vdc. Most modern mixers provide phantom
power. Phantom power can only be transmitted to the KSM27 through a cable
terminated with XLR connectors at each end.

4
Positioning the Microphone
The front of the KSM27 is marked by the Rlogo. See Figure 1. Position this
side of the microphone toward the sound source to be recorded. The rear of the
microphone is marked by the logo, the low-frequency filter switch and the 15dB
attenuation switch.
Cardioid. Picks up sounds directly in front of the microphone and is least
sensitive to those in back. Cardioid is the most commonly used polar pattern in studio
recording and live-sound applications. See Figure 5.
Selecting Low-Frequency Response
A three-position switch on the back of the KSM27 lets you adjust the low-frequency
response of the microphone. The low-frequency filter settings can be used to reduce
wind noise, room noise or proximity effect. Since the microphone will reproduce
ultra-low frequencies, the rubber isolated shock mount should be used to reduce
low-frequency mechanical vibrations transmitted through the microphone stand.
Flat response. Provides the most natural sound in most applications.
Low-frequency cutoff. Provides an 18
dB-per-octave cutoff at 80 Hz. 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 6
dB-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.
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+5
0
–10
Hz
dB
Low-Frequency Cutoff
Low-Frequency Rolloff
Flat Response
FIGURE 2. LOW FREQUENCY RESPONSES

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Setting Attenuation
The attenuation switch on the back of the KSM27 reduces the signal level from the
cartridge by 15 dB without altering the frequency response. This can prevent
extremely high SPLs (ie. close miked drums and guitar cabinets) from overloading
the microphone. To activate attenuation, move the switch to the “-15 dB” position.
0 dB – Use this switch for “quiet” to “normal” sound levels.
-15 dB – Use this switch position when in close proximity with extremely loud
sound sources such as kick drum, snare drum, or loud guitar cabinets.
Integral Pop Filter
The KSM27 grille consists of 3 separate mesh layers that act as an integral pop filter
which helps reduce wind and breath noise. Depending on the performer, an external
pop-protection screen or windscreen (See Figure 3) may be necessary when
close-miking vocalists.
FIGURE 3. PS–6 POPPER STOPPERTPOP FILTER
Load Impedance
Shure recommends a load impedance of at least 1000 Ω. When used with modern
microphone preamplifiers (rated at 2500 Ω), the KSM27 provides higher maximum
SPL capability and output clipping level. When the attenuation switch is set to the
–15 dB position, the KSM27 can handle sound pressure levels of up to 152 dB and
output +15 dBV into a load of 2500 Ωor greater.

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SPECIFICATIONS
Cartridge Type Externally Biased Condenser
Frequency Response 20 to 20,000 Hz (see Figure 4)
Directional Polar Pattern Cardioid (see Figure 5)
Output Impedance EIA Rated at 150 Ω(140 Ωactual)
Attenuation Switch 0 or 15 dB attenuation
Low Frequency response switch flat; –6 db/octave below 115 Hz;
–18 dB/octave below 80 Hz
Phantom Power 48 Vdc ±4 Vdc (IEC–268–15/DIN 45 596), positive
pins 2 and 3
Current Drain 5.4 mA typical at 48 Vdc
Common Mode Rejection ≥50 dB, 20 Hz to 20 kHz
Polarity Positive pressure on diaphragm produces positive
voltage on output pin 2 relative to pin 3
Dimensions and Weight 53.0 mm (2.08 in.) maximum body diameter,
156.2 mm (6.15 in.) long; 642 grams (22.6 oz.)
(see Figure 6)
Sensitivity (typical, at 1000 Hz;
1Pa = 94 dB SPL) –37 dBV/Pa
Self–noise (typical, equivalent SPL;
A–weighted, IEC 651) 14 dB
Maximum SPL at 1000 Hz
2500 Ωload (Attenuator on)
1000 Ωload (Attenuator on)
137 (152) dB
132 (147) dB
Output Clipping Level*
2500 Ωload
1000 Ωload
7 dBV
1 dBV
Dynamic Range
2500 Ωload
1000 Ωload
123 dB
118 dB
Signal to Noise ratio** 80 dB
*20 Hz to 20 kHz; THD < 1%. THD of the microphone preamplifier when applied input signal is equivalent to the cartridge output at specified SPL.
**S/N ratio is difference between 94 dB SPL and equivalent SPL of self-noise A-weighted.

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60 cm
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20 200001000 1000050 100 98765432 98765432
+10
0
–10
Hz
dB
FIGURE 4. TYPICAL FREQUENCY RESPONSE
FIGURE 5. TYPICAL POLAR PATTERNS
150o
120o
150o
120o
180o
30o
60o
90o
30o
60o
90o
30o
60o
90o
150o
120o
150o
120o
180o
30o
60o
90o
250 Hz
1000 Hz
500 Hz 2500 Hz
10000 Hz
6400 Hz
0o 0o
–5 dB
–10 dB
–15
dB
–20 dB
+5 dB
–5 dB
–10 dB
–15
dB
–20 dB
+5 dB
FIGURE 6. DIMENSIONS
156,2 mm
(6.15 IN.)
50,8 mm
(2.00 IN.)
53,0 mm
(2.08 IN.)
150,1 mm
(5.90 IN.)

8
CERTIFICATION
Eligible to bear CE Marking; Conforms to European EMC directive 89/336/EEC.
Meets applicable tests and performance criteria found in European Professional
Audio Products EMC Standard EN 55103 (1996); Part 1 (Emissions) and Part 2
(Immunity). The KSM27 is intended for use in environments E1 (residential) and E2
(Light Industrial) as defined in European standard EN 55103. EMC conformance is
based on the use of shielded interconnecting cable.
N 108
FURNISHED ACCESSORIES
ShureLocktRubber Isolated Shock Mount A27SM. . . . . . . . . . . . . . . . . . . . . .
Protective Velveteen Pouch A27VB. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OPTIONAL ACCESSORIES
ShureLocktBlack Swivel Adapter A32M. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Aluminum Carrying Case A32SC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Windscreen A32WS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Popper StoppertPop Screen PS–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Padded, Zippered Carrying Bag A32ZB. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
REPLACEMENT PARTS
Rubber Rings for Shock Mount (contains four) RPM642. . . . . . . . . . . . . . . . . . .
ReplacementFoam for Carrying Case 29A2284. . . . . . . . . . . . . . . . . . . . . . . . .
SERVICE
For additional microphone service or parts information, please contact the Shure
Service department at 1-800-516-2525. Outside the United States, please contact
your Authorized Shure Service Center.

Trademark Notices: The circular S logo, the stylized Shure logo, and the word
“Shure” are registered trademarks of Shure Incorporated in the United States.
“ShureLock” is a trademark of Shure Incorporated in the United States. “Mylar”
is a registered trademark of E.I. duPont de Nemours and Company in the United
States. These marks may be registered in other jurisdictions.
Patent Notice: Patent Des. 400,540 Des. 447,131