2
POWERING THE SM93 PREAMPLIFIER
Power the preamplifier supplied with the SM93 using any
phantom supply providing 11 to 52 Vdc, such as the Shure
Model PS1A Power Supply.
SM93 PREAMPLIFIER IMPEDANCE
Use a minimum load impedance of 800
Ω
or greater for
maximum signal handling and minimum distortion. Load as
low as 150
Ω
can be used, but a reduction in output clipping
level will result. Note that the power supply itself may add
loading (3300
Ω
in the Shure PS1A) to the microphone.
USING OTHER PREAMPLIFIERS OR BODY–PACKS
If connecting the 93 microphone to anything OTHER than
a Shure wireless body-pack or the preamplifier supplied with
the SM93, make sure it provides a reg5 Vdc source
(
40
m
A
minimum) at pin 2 of the microphone connector, as
shown in Figure 2.
CONDENSER
CARTRIDGE
IMPEDANCE
CONVERTER
G
SHIELD
BLK
RED
S
D+
4
1
2
3
MICROPHONE WIRING DIAGRAM
FIGURE 2
SPECIFICATIONS
WL93 MICROPHONE
(with standard test circuit
shown in Figure 3)
SM93 MICROPHONE
(with preamplifier)
Type
Condenser (electret bias)
Condenser (electret bias)
Frequency Response (Figure 4)
50 to 20,000 Hz
80 to 20,000 Hz, 12 dB/octave rolloff below 100 Hz
Polar Pattern
Omnidirectional, uniform with frequency
Omnidirectional, uniform with frequency
Output Impedance
3000
Ω
Rated at 150
Ω
(90
Ω
actual)
Recommended minimum load impedance: 800
Ω
(May be used with loads as low as 150
Ω
with reduced
clipping level)
Output Level
(1 Pascal = 94 dB SPL)
Open Circuit Voltage: –38 dBV/Pa
(13 mV)
Open Circuit Voltage: –43 dBV/Pa (7.0 mV)
Output Clipping Level
(at 1,000 Hz)
0.25 V at 120 dB
–18 dBV (0.13 V) minimum
Total Harmonic Distortion
Less than 1% at 120 dB
Less than 1% at 120 dB
Maximum SPL
120 dB
120 dB
Dynamic Range (maximum SPL
to A-weighted noise level)
102 dB
98 dB
Output Noise (equivalent SPL)
18 dB typical, A-weighted
22 dB typical, A-weighted
26 dB, weighted per DIN 45 405
Hum Pickup (electromagnetic)
N/A
–4 dB equivalent SPL in a 1 mOe field (60 Hz)
Signal-to-Noise Ratio
76 dB at 94 dB SPL (IEC 651)
72 dB at 94 dB SPL (IEC 651)
Polarity
Positive pressure on microphone diaphragm
produces positive voltage on pins 3 and 4 with
respect to pin 1 (ground)*
Positive pressure on microphone diaphragm produces
positive voltage on pin 2 relative to pin 3 of preamplifier
output cable connector
Recommended Operating
Voltage
2 to 10 V; 5 V nominal (pin 2 to pins 3 and 4)
11 to 52 Vdc phantom. Protected against reverse
voltage application
Current Drain
40
m
A typical
0.33 mA
Environmental Conditions
Operating Temperatures:
–18
o
to 57
o
C
(0
o
to 135
o
F)
Storage Temperatures:
–29
o
to 74
o
C
(–20
o
to 165
o
F)
Operating Temperatures: –18
o
to 57
o
C (0
o
to 135
o
F)
Storage Temperatures: –29
o
to 74
o
C (–20
o
to 165
o
F)
Cable
Black 1.27 m (4.17 ft), attached, two-conductor,
shielded, terminated by miniature connector type
TA4F (WL93T: Tan 1.27 m [4.17 ft])
Black 1.27 m (4.17 ft), attached, two-conductor,
shielded, terminated by miniature connector type
(TA4F)
Case
Microphone: Black ABS thermoplastic case with
stainless-steel-mesh grille
Microphone: Black ABS thermoplastic case with
stainless-steel-mesh grille
P
lifi St l
ith
fl ti bl k
Preamplifier: Steel case with non–reflective black
finish, black–chrome belt clip
Net Weight
Microphone: 16 g (0.57 oz)
Microphone: 16 g (0.57 oz)
g
Preamplifier: 118 g (4.17 oz)
* Produces positive voltage at pin 2 of Shure L4/EC4 wireless receiver three–pin connector.
