AP - The Recognized Standard In Audio Test


GRAS Products

About G.R.A.S.


Audio Precision is proud to be an official reseller for G.R.A.S. Sound and Vibration. G.R.A.S. enjoys an extraordinary reputation in the field of sound and vibration, and is known for world-class acoustic products.

AP now offers a complete solution to customers looking to test devices with acoustic interfaces, matching the world’s best audio analyzers with the highest quality measurement mics, power supplies, calibrators, and accessories.

Both R&D and production test users now have a complete solution available from a single source for end-to-end testing utilizing acoustic, analog, AES digital, serial digital, HDMI, PDM (MEMS mics), and Bluetooth interfaces.

G.R.A.S. Products

We carry several microphones for different applications, plus various ear and mouth simulators, including the KEMAR Head And Torso Simulator (HATS). Datasheets may be downloaded directly from the G.R.A.S website.


For smartphone and tablet customers, the KEMAR head and torso simulator, handset positioner, and ear and mouth simulators are essential tools for making measurements to international standards.

Ear Simulator and KEMAR Ear and Mouth Simulators
  • 43AB Artificial ear kit w/2cc IEC 126 coupler
  • 43AC Artificial ear kit w/IEC 711 coupler
  • 43AG Ear and cheek simulator
  • 44AA Artificial mouth
Complete information for 43AB artificial ear kit
Complete information for 43AC artificial ear kit
Complete information for 43AG ear and cheek simulator
Complete information for 44AA artificial mouth kit


Head and Torso Simulator
  • Complete line of KEMAR head & torso simulators
  • 45EA Telephone handset positioner with neck ring for KEMAR
View the complete range of KEMAR models and options.
Download full specifications for 45EA Telephone handset positioner with neck ring for KEMAR




MMK-4 Measurement Microphone Kit

This kit combines the popular 46AE high precision measurement microphone (see details below) with the 12AL power supply, and replaces the MMK-2 Measurement Microphone Kit.

  • 46AE Microphone
  • 12AL power supply
  • BNC cable
  • 42AB calibrator (optional)
Download MMK-4 datasheet


High Precision Microphone Sets

Designed for uncompromised performance in critical measurement situations, the 46 series sets are suitable for class 1 audio measurements. Each set is comprised of a prepolarized capsule mated to a preamp body, sealed together with a label, and calibrated as a unit. This simplifies microphone selection and ordering.

  • 46AE 1/2” High precision microphone set, free field, constant current power. More Info
  • 46AO 1/2” High precision microphone set, pressure, constant current power. More Info
  • 46BE 1/4” High precision microphone set, free field, constant current power. More Info


Cost Effective Microphone Sets

The 40PH measurement microphone is suitable for class 2 audio measurements used in production test. It is a one-piece integrated capsule/preamp design, with a 1/4” prepolarized free-field capsule. Although its self-noise, overload, and response accuracy do not match the high precision offerings, it is perfectly suited to many production-line applications.

  • 40PH 1/4” Cost effective microphone for production test. More Info


Mic Calibrators
  • 42AB Sound calibrator 1 kHz, 114 dBSPL. More Info
  • 42AA Pistonphone 250 Hz, 114 dBSPL. More Info


Power Modules
  • 12AL 1-channel microphone power module, constant current
    (used for all sets listed above). More Info
  • 12AR 2-channel microphone power module, 200 volt. More Info
  • 12AD 1-channel microphone power module, 200 volt. More Info


Hearing Protector Test Fixture

  • 45CA Complete hearing protector test fixture with couplers. More Info

See the complete listing of other accessories.


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