2
Polar Pattern
Hypercardioid at low frequencies, lobar at frequencies above
1 kHz, symmetrical about axis.
150°
120°
150°
120°
180°
30°
60°
90°
30°
60°
0
90°
–10 dB
–20 dB
–15 dB
–5 dB
150°
120°
150°
120°
180°
30°
60°
90°
30°
60°
0
90°
–10 dB
–20 dB
–15 dB
–5 dB
500 Hz
1000 Hz
250 Hz
6300 Hz
10000 Hz
2500 Hz
TYPICAL POLAR PATTERNS
Curves shown at 1.8m (6 ft)
Output Impedance
Rated at 150 Ω (100 Ω actual)
Recommended minimum load: 800 Ω (May be used
with loads low as 150 Ω with reduced clipping level)
Sensitivity:
(at 1,000 Hz)
Open Circuit Voltage . . . . . . . . –33 dBV/Pa (22.2 mV)
1 Pascal = 94 dB SPL
Output Clipping Level
(at 1,000 Hz, under 0.5% THD)
800 Ω load: –1 dBV (0.89 V)
150 Ω load: –12 dBV (0.25 V)
Maximum SPL
(at 1,000 Hz, under 0.5% THD)
800 Ω load: 127 dB SPL
150 Ω load: 119 dB SPL
Hum Pickup
Under 3 dB equivalent SPL in 1 mOe field (60 Hz)
Output Noise
16 dB SPL typical, A-weighted
Signal-to-Noise Ratio
79 dB re 94 dB SPL
Dynamic Range
111 dB
Phasing
Positive pressure on diaphragm produces positive voltage on
pin 2 relative to pin 3 of microphone output connector
Power
Phantom voltage: 11 to 52 Vdc; 2 mA current drain
Low-Cut Filter
Recessed low-cut filter switch, 15 dB/octave cut below
60 Hz(—) or 160 Hz ( )
Case
Satin-black vinyl painted aluminum alloy handle and grille with
stainless steel screen
Dimensions
524 mm (20-5/8 IN.)
20 mm (25/32 IN.) DIA
386 mm (15-3/16 IN.)
OVERALL DIMENSIONS
Environmental Conditions
Operating Temperature: –29 to 57° C (–20 to 135°F)
Relative Humidity (Operating): 0 to 95%
Storage Temperature: –29 to 74° C (– 20 to 165°F)
Relative Humidity (Storage): Up to 80% at 74° C
(165° F)
Net Weight
195 grams (6.9 oz)
POWERING THE SM89
The SM89 is designed for connection to widely available 11 to
52 Vdc phantom-powered microphone inputs. Suitable inputs
are found in such Shure units as Mixer Models M267, M268,
FP31, FP32, and FP42, Distribution Amp Model FP16, and Power
Supply Model PS1A.
FET
IMPEDANCE
CONVERTER
CAPACITOR
CARTRIDGE
BALANCED
TRANSFORMER
LF RESPONSE
FILTER
CLASS A
COMPOUND
AMPLIFIER
RF1
FILTER
REGULATOR/
REVERSE
VOLTAGE
PROTECT
BLOCK DIAGRAM
USING THE DIRECTIONAL QUALITIES OF THE SM89
Because of its minimum comb-filter effects, the SM89 has a
unique advantage over other shotgun microphones when good
sound would otherwise be difficult or impossible to pick up.
For instance, in a relatively nonreverberant location, the SM89
can be aimed so that the noise source is entirely off-axis to the
microphone even if this puts the desired source up to 30° off-axis.
The noise pickup will then be minimal, and the SM89 will pick
up the desired source with slightly diminished high-frequency
response.
*Curves shown at 1.8m (6 ft)
COMPARISON OF 30 AND 90 OFF-AXIS
COMPARISON OF 30 ° AND 90 ° OFF-AXIS RESPONSE OF SM89
Curves shown at 1.8m (6 ft)
