Crown LM-301A Manual page 2

LM-301A
T
he Crown © LM-301A is a supercardioid,
electret condenser, miniature dual goose-
neck microphone. It is designed for pro-
fessional use on lecterns and for inconspicu-
ous miking of musical instruments. The
LM-301A comes in two parts: microphone/
cable and a cylindrical electronics housing.
The microphone has a built-in 5 / -inch (15.88-
8
mm)-27 threaded collar that can be screwed
onto a mic stand, mic boom or an Atlas AD-12
male flange. Because of the unique design of
the mounting collar, the mic cable can be
routed either outside or inside the mounting
collar.
Because of its supercardioid pickup pattern,
the LM-301A rejects more background noise,
room reverberation, and feedback than a typi-
cal cardioid microphone.
The LM-301A has a smooth, wide-range fre-
quency response for natural reproduction of
the singing or speaking voice. Very low fre-
quencies are filtered out to reduce pickup of
mechanically induced noise, room rumble, etc.
The gooseneck adjusts silently.
Supplied with the microphone is the WS-9, a
highly effective foam pop filter. Its two-stage
design greatly reduces explosive breath
sounds. A low-cut switch built into the elec-
tronics housing further reduces breath pops
and handling noise. Optional accessories in-
clude the LM-301SMA shock mount adapter.
The microphone output is a male 3-pin XLR-
type connector and is balanced, low imped-
ance, which allows long cable runs without
hum pickup or high-frequency loss. Superior
RFI protection is also provided.
Operating Instructions
Please refer to Fig. 3 to identify the parts men-
tioned.
1. To route the mic cable inside the mounting
device: remove the TA3F connector, push the
collar up onto the gooseneck and pull the
cable down through the collar. Reattach TA3F.
2. To route the mic cable outside the mounting
device: remove the TA3F connector, push the
collar up onto the gooseneck, route the end of
the cable inside the collar and slot and pull the
cable up through the collar and slot. Reattach
TA3F.
3. Plug the electronics interface into a 3-pin
XLR-type cable routed to the audio mixer.
4. At the mixer, plug the mic cable from the
lectern into an input with 12-48 volt phantom
SUPERCARDIOID CONDENSER
DUAL GOOSENECK
LECTERN MICROPHONE
Specifications
Type: Unidirectional condenser.
Element: Electret condenser.
Frequency response (typical): 80 Hz to 15,000 Hz
(110 Hz to 15,000 Hz with low cut). See Fig. 1.
Polar pattern: Supercardioid. See Fig. 2.
Impedance: 150 ohms, balanced. Recommended
minimum load impedance 1000 ohms.
Open-circuit sensitivity: 6 mV/Pa* (–44.5 dB re
1 V/Pa*).
Power sensitivity: –42 dB re 1 mW/Pa*.
Equivalent noise level: 28 dB SPL typical
(0 dB=.0002 dyne/cm 2 ), A-weighted.
S/N ratio: 66 dB at 94 dB SPL.
Maximum SPL: 120 dB SPL produces 3% THD.
Polarity: Positive pressure on the diaphragm
produces a positive voltage on pin 2 with respect
to pin 3 of the output connector.
Operating voltage: Phantom power, 12 to 48 volts
DC, positive voltage on pins 2 and 3 with respect
to pin 1 of the output connector.
Current drain: 3.5 mA.
Cable: 10' (3.05-m) 2-conductor shielded 0.1"
diameter cable integral to microphone terminated
with Switchcraft TA3F.
Connectors: Switchcraft TA3F on mic cable, TB3M
and 3-pin male XLR type in electronics interface.
Materials: Steel housing and gooseneck.
Finish: Black.
Weight: 5.5 ounces (159 grams).
Dimensions: See Fig. 3 on reverse side.
Included accessories: WS-9 foam pop filter (Fig. 4).
Optional accessories: WS-5 foam windscreen, LM-
301SMA shock mount adapter and windscreen.
PH-4B phantom power supply (4 channels,
AC powered), PH-1A phantom power supply
(1 channel, battery or AC adaptor powered),
PS-24 24V DC power supply for PH-1A.
*1 pascal = 10 microbars = 10 dynes/cm
SPL.
Fig. 1
Frequency Response
+15
+10
+5
dB 0
FLAT
–5
LOW-CUT
–10
–15
–20
–25
–30
–35
20 100
Fig. 2
330˚
300˚
270˚
240˚
210˚
2 = 94 dB
0, 6"
130, 2'
1K 10K
Frequency in Hz
Polar Response
0˚
30˚
FRONT
-0
60˚
-5
-10
-15
-20
90˚
120˚
400 Hz-7kHz
REAR
180˚ 150˚