Shure SM84

Type: Condenser (electret bias)
Frequency Response: 80 to 20,000 Hz
Polar Pattern: Supercardioid response —narrower than cardioid for higher directionality, superior rejection of undesirable sounds
Impedance:

• Rated at 150 ohms (90 ohms actual)
• Recommended minimum load impedance: 800 ohms (May be used with loads as low as 150 ohms with reduced clipping level)

Output Level (at 2,000 Hz):

• Open Circuit Voltage ............... — 73 dB (0.22 mV)

Clipping Level (at 2,000 Hz):

• 800-ohm Load ............................. —17 dBV (0.14V)
• 150-ohm Load ............................. —28 dBV (0.04V)

Total Harmonie Distortion: Less than 1% (126 dB SPL at 2,000 Hz into 800-ohm load)
Maximum SPL: 131 dB with 800-ohm load 123 dB with 150-ohm load
Hum Pickup: — 3 dB equivalent SPL in a 1 millioersted field (60 Hz)
Output Noise (equivalent sound pressure levels; measured with true rms voltmeter)

• 30 dB typical, A-weighted
• 34 dB typical, weighted per DIN 45 405

Dynamic Range: 101 dB (maximum SPL to A-weighted noise level)
Signal-to-Noise Ratio: 64 dB (IEC 651) at 94 dB SPL
Phasing: Positive pressure on diaphragm produces positive voltage on pin 2 relative to pin 3
Power:

• Battery: 9 Vdc (type 1604A, alkaline recommended); 33 mA current drain; approximately 1600 hours con- tinuous use with fresh alkaline battery
• Phantom Voltage: 5 to 52 Vdc; 0.33 mA current drain Protected against

Net Weight

• Microphone: 45 grams
• Amplifier: 270 grams  including battery