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CardioidAudio-Technica ATM31a

MSRP: $250 Cardioid Condenser Microphone

Audio-Technica ATM31a

Description

The ATM31a is a cardioid condenser mic with a “fixed-charge back plate, permanently polarized condenser.”

  • Ideal for close-up vocals, overheads, piano and strings
  • Sound is similar to far more expensive studio microphones
  • Low-mass diaphragm ensures minimum distortion
  • Cardioid pattern provides added warmth when used close up
  • Operates on battery or phantom power

Note that the specs change if you run the mic off an AA batter rather than phantom power. Using a battery:

  • Impedance changes from 200 ohms to 270 ohms
  • Dynamic range drops from 113 dB to 99 dB
  • Sensitivity changes from -44dB (6.3 mV) to -45dB (5.6 mV)

The ATM31a is an improvement over the original ATM31 (circa 1981); the original specs follow:

  • Freq. Resp.: 60 to 20,000 Hz
  • Impedance: 600 ohms
  • Sensitivity: -55 dBm

The Audio-Technica ATM31a is also known as: ATM31, ATM-31, ATM-31a.

The mic was released in 1981.

Pickup Patterns Pads & Filters
Cardioid (6.3 mV/Pa; 30 - 20,000 Hz)
Capsule Dimensions Impedance SPL/Noise
Diameter n/a
 200 Ohms (Low) Max SPL: 137 dB
Self-noise: 14.0 dB(A)
Weight Length Max Diameter Interface(s)
200g (7.05oz) 193mm (7.60'') 50mm (1.97'')
  • 3-pin XLR male (1)
Power Specifications
  • Requires Phantom Power
  • Has Battery Compartment (1.5V AA/UM3)
  • Phantom voltage: 9-52V DCv

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