Mic Archive
Shure SM84
Photo: Shure, from its user guide, p. 1.

Shure

Shure SM84

Miniature supercardioid electret condenser lavalier for broadcast and sound reinforcement, with a belt-pack amplifier (9 V battery or phantom power)

Approximate Some readings for this mic are uncertain; see the graphs.

Type
Condenser (electret)
Pattern
Supercardioid
Sensitivity
−53 dBV/Pa computed
Self-noise
30 dB(A)
Max SPL
131 dB SPL
Impedance
150 Ω
Rated range
80 – 20k Hz

Frequency response

Angle
Distance

Frequency response: from the user guide, p. 2. "Typical frequency response" (Figure 1); relative dB, 5 dB per division, no dB labels: set to 0 dB at 1 kHz. Distance, room and smoothing not stated; the guide says the response is "specially tailored for chest-worn microphone operation" (730 Hz dip and a presence rise).

Dashed: outside the rated range, or simulated (other angles and distances). Hover or tap the graphs for values.

Polar pattern

Polar pattern: from the user guide, p. 2. "Typical polar patterns" (Figure 2); two full circles, 0° at the bottom, rings at 0 (outer) and -5 to -20 dB. Measuring conditions not stated. Approximate reading error up to about 1 dB.

Compare with other mics

All specs

From the user guide
Sensitivity−53 dBV/Pa, open circuit, 2 kHz. Not stated by the manufacturer: Converted: "Output Level (at 2,000 Hz) Open Circuit Voltage –73 dB (0.22 mV) (0 dB = 1 volt per microbar)"; 1 Pa = 10 microbar, so +20 dB (2.2 mV/Pa).p. 2
Self-noise30 dB(A), typical, true rms voltmeter. "Output Noise (equivalent sound pressure level; measured with true rms voltmeter) 30 dB typical, A-weighted; 34 dB typical, weighted per DIN 45 405".
Max SPL131 dB SPL, 800 ohm load; also 123 dB SPL, 150 ohm load. "Maximum SPL 131 dB with 800-ohm load, 123 dB with 150-ohm load"; THD "Less than 1% (126 dB SPL at 2,000 Hz into 800-ohm load)".
Signal-to-noise ratio64 dB, IEC 651, at 94 dB SPL
Dynamic range101 dB, maximum SPL to A-weighted noise
Output impedance150 ohm, rated; 90 ohm actual. "Rated at 150 ohms (90 ohms actual)".
Rated load impedance800 ohm, recommended minimum; usable down to 150 ohm with reduced clipping level
Rated frequency range80 Hz to 20 kHz. "80 to 20,000 Hz (see Figure 1)".p. 1
Powering9 V battery (type 1604A) or phantom 5-52 V DC. "Battery: 9 Vdc (type 1604A, alkaline recommended); 0.33 mA current drain; approximately 1600 hours"; "Phantom Voltage: 5 to 52 Vdc; 0.33 mA current drain". Automatic switchover to phantom (page 1).p. 2
Current draw0.33 mA
ConnectorXLR-3 male on the amplifier cable; miniature 3-pin (TA3) between mic and amplifier. Cables: microphone "3 m (10 ft) attached ... with miniature 3-pin connector" (Switchcraft TA3); amplifier "3 m (10 ft) attached, ... TRIPLE-FLEX® with 3-pin professional audio connector" (Cannon XL, Switchcraft A3).
Weight45 g, microphone. "Microphone: 45 grams (1.58 ounces); Amplifier: 270 grams (9.45 ounces) including battery".
Dimensions26.2 × 11.2 mm. Figure 3, microphone: length × diameter. Amplifier 84.1 × 49 × 23.1 mm; mic connector 10.6 mm diameter.
Finishflat black, black steel-mesh grille. "Microphone: Brass construction with flat black finish and black steel-mesh grille".
Supplied accessoriesmounting blocks (lanyard, safety pin, sewing); single-mount tie bar; dual-mount tie bar; acoustic foam windscreen; carrying/storage bag. Page 1 lists them; page 5: mounting block RK239MB, single-mount tie bar RK240SB, dual-mount tie bar RK241DB, windscreen RK261WS (each kit four units), bag 26A08.p. 1
Chest-worn voicingElectronically created dip at 730 Hz to offset chest resonance, acoustic high-frequency boost for a flatter response in the lavalier position, 12 dB/octave roll-off below 100 Hz
Noise (DIN 45 405)34 dB typical, weighted per DIN 45 405p. 2
Clipping level (2 kHz)–17 dBV (0.14 V) into 800 ohm; –28 dBV (0.04 V) into 150 ohm
Hum pickup–3 dB equivalent SPL in a 1 millioersted field (60 Hz)
AmplifierBlack high-impact plastic case with detachable belt clip; FET impedance converter in the mic; 730 Hz notch filter, 12 dB/octave high-pass, transformer-balanced output, RFI filters; no on-off switchp. 4
Wireless useCan be wired to a wireless transmitter input without the amplifier (no 730 Hz dip then)p. 5
TemperatureOperating –18 to 60 °C; storage –29 to 66 °Cp. 2
PhasingPositive pressure on the diaphragm gives positive voltage on pin 2 relative to pin 3
Replacement partsCartridge-housing R146; mic-amplifier cable C109; battery door 65A1536; belt clip 44A279p. 5
Power supply (Shure)PS1A dual-channel phantom supplyp. 1

Documents

Copies kept by Mic Archive, because manufacturers move and drop their documents. Each is © Shure, unchanged, with its original address.

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