2
SPECIFICATIONS
WM98 MICROPHONE (with standard test
circuit–Figure 6)
SM98A MICROPHONE
Type
Condenser (electret bias)
Frequency Response (Figs. 1–2)
40 to 20,000 Hz
Polar Pattern (Figs. 3–4)
Unidirectional (cardioid) or supercardioid with A98SPM Supercardioid Polar Modifier
Output Impedance
1200
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 clip-
ping level)
Output Level
(0 dB = 1 volt per
m
bar)
Open Circuit Voltage
–74 dB (0.2 mV)
. . . . . . .
Open Circuit Voltage
–80 dB (0.10 mV)
. . . . . . .
Output Clipping Level
(at 1,000 Hz)
–3 dBV (0.70 V)
800
Ω
Load, ILP–1 gain = 0 dB
0 dBV (1.0 V)
. . . . . . . . . . .
800
Ω
Load, ILP–1 gain = +10 dB
–7 dBV (0.45 V)
. . . . . . .
150
Ω
Load, ILP–1 gain = 0 dB
–13 dBV (0.22 V)
. . . . . . . .
150
Ω
Load, ILP–1 gain = +10 dB
–21 dBV (0.09 V)
. . . . . .
Total Harmonic Distortion
Less than 1% (134 dB SPL at 1,000 Hz)
Less than 1% (132 dB SPL at 1,000 Hz)
Maximum SPL
145 dB
800
Ω
Load, ILP–1 gain at 0 dB
155 dB
. . . . . . . . . . . . . . . . .
800
Ω
Load, ILP–1 gain at +10 dB
138 dB
. . . . . . . . . . . . . .
150
Ω
Load, ILP–1 gain at 0 dB
145 dB
. . . . . . . . . . . . . . . .
150
Ω
Load, ILP–1 gain at +10 dB
127 dB
. . . . . . . . . . . . . .
Dynamic Range (maximum SPL
to A-weighted noise level)
111 dB
121 dB (800
Ω
load, ILP–1 gain at 0 dB)
Output Noise (equivalent SPL)
34 dB typical, A-weighted
40 dB typical, C-weighted
37 dB, weighted per DIN 45 405
Hum Pickup (electromagnetic)
N/A
–5 dB equivalent SPL in a 1 mOe field (60 Hz)
Signal-to-Noise Ratio
60 dB at 94 dB SPL (IEC 651)
60 dB at 94 dB SPL (IEC 651)
Response Shaping
N/A
Flat/Lo Cut Preamp switch; Lo Cut: 12 dB rolloff below 80 Hz
Phasing
Positive pressure on microphone diaphragm pro-
duces positive voltage on pins 3 and 4 with re-
spect to pin 1 (ground)
Positive pressure on microphone diaphragm produces posi-
tive voltage on pin 2 relative to pin 3 of preamplifier output
connector
Recommended Operating Volt-
age
1.5 to 6 V (pin 2 to pins 3 and 4)
11 to 52 Vdc Phantom; operational down to 9 Vdc with re-
duced clipping level
Current Drain
60 to 180
m
A
2.2 mA current drain at 52 Vdc, 1.8 mA at 11 Vdc
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)
. . . . . . . . . . . . . . . . . . .
Relative Humidity
0 to 95% (operating or storage)
. . . . . . . . . . . . . . . . . . . . . .
Cable
Microphone: 1.12 m (3 ft 8 in.), attached, two-con-
ductor, shielded with miniature 3– and 4–pin con-
nectors (Switchcraft “Tini Q–G” type)
Microphone: 4.6 m (15 ft), two-conductor, shielded with minia-
ture 3–pin female connector (Switchcraft TA4F type) on each
end to mate with microphone output and preamplifier input
Case
Microphone: Brass construction with matte black
finish and black stainless-steel-mesh grille
Microphone: Brass construction with matte black finish and
black stainless-steel-mesh grille
Amplifier: Steel construction with matte black enamel finish
Net Weight
Microphone: 12 g (0.4 oz)
Microphone: 12 g (0.42 oz)
Amplifier: 170 g (6.0 oz)
Certifications
Conforms to European Union directives, eligible
to bear CE marking; meets European Union EMC
Immunity Requirements (EN 50 082–1, 1992).
TYPICAL POLAR PATTERNS
FIGURE 3
TYPICAL POLAR PATTERNS – SM98A WITH A98SPM
INSTALLED
FIGURE 4
