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.
Power 9 V battery (type 1604A) or phantom 5-52 V DC.
- Type
- Condenser (electret)
- Pattern
- Supercardioid
- Sensitivity
- −53 dBV/Pa computed
- Self-noise
- 30 dB(A)
- Among 272 mics: quieter than 4%
- Max SPL
- 131 dB SPL
- Among 343 mics: takes louder sound than 22%
- Rated range
- 80 – 20k Hz
vs 258 condensers
Quieter than 4% of 258 condensers.
Each stripe is one condenser with a published self-noise, and each bar counts them; further right means quieter. This mic is in blue.
vs 277 condensers
Takes louder sound than 24% of 277 condensers.
Each stripe is one condenser with a published max SPL, and each bar counts them; further right means it takes louder sound. This mic is in blue.
Instruments sources recommend it for most
Proximity effect: the bass it gains up close
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
From the user guide, p. 2. Approximate
"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.
In practice
All specs
| From the user guide | ||
|---|---|---|
| Sensitivity | −53 dBV/Paopen 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-noise | 30 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 SPL | 131 dB SPL800 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 ratio | 64 dBIEC 651, at 94 dB SPL | |
| Dynamic range | 101 dBmaximum SPL to A-weighted noise | |
| Output impedance | 150 ohmrated; 90 ohm actual. "Rated at 150 ohms (90 ohms actual)". | |
| Rated load impedance | 800 ohmrecommended minimum; usable down to 150 ohm with reduced clipping level | |
| Rated frequency range | 80 Hz to 20 kHz"80 to 20,000 Hz (see Figure 1)". | p. 1 |
| Powering | 9 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 draw | 0.33 mA | |
| Connector | XLR-3 male on the amplifier cable; miniature 3-pin (TA3) between mic and amplifierCables: 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). | |
| Weight | 45 gmicrophone. "Microphone: 45 grams (1.58 ounces); Amplifier: 270 grams (9.45 ounces) including battery". | |
| Dimensions | 26.2 × 11.2 mmFigure 3, microphone: length × diameter. Amplifier 84.1 × 49 × 23.1 mm; mic connector 10.6 mm diameter. | |
| Finish | flat black, black steel-mesh grille"Microphone: Brass construction with flat black finish and black steel-mesh grille". | |
| Supplied accessories | mounting blocks (lanyard, safety pin, sewing); single-mount tie bar; dual-mount tie bar; acoustic foam windscreen; carrying/storage bagPage 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 voicing | Electronically 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 | |
| NoiseDIN 45 405 | 34 dB typical, weighted per DIN 45 405 | p. 2 |
| Clipping level2 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) | |
| Amplifier | Black 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 switch | p. 4 |
| Wireless use | Can be wired to a wireless transmitter input without the amplifier (no 730 Hz dip then) | p. 5 |
| Temperature | Operating –18 to 60 °C; storage –29 to 66 °C | p. 2 |
| Phasing | Positive pressure on the diaphragm gives positive voltage on pin 2 relative to pin 3 | |
| Replacement parts | Cartridge-housing R146; mic-amplifier cable C109; battery door 65A1536; belt clip 44A279 | p. 5 |
| Power supplyShure | PS1A dual-channel phantom supply | p. 1 |
Documents
- Model SM84 Supercardioid Lavalier Microphone, Technical Data27A2342
Copies kept by Mic Archive (manufacturers move and drop their documents). Each is © Shure, unchanged, with its original address.
Recommended for
By recording guides, engineers and mic makers, for this mic or an earlier version of it.