Frequently Asked Questions

The maximum level a microphone can handle is usually specified as the “dynamic range upper limit”. If we look at ½” measurement microphones, we can see…

Microphone sets are pre-made combinations of microphones capsules with preamplifiers. The measurement microphone sets have been…

Dust/dirt can be problematic when in contact with a measurement microphone set. The accumulation of dust in the protection grid can…

Even though GRAS microphones are tested for Vibration and Mechanical Impulsive Stress tests during our HALT (Highly Accelerated Lifetime Test) procedure, every time a microphone...

Choosing the right measurement microphone is essential for obtaining useful measurement data. The different types of microphones are designed for...

Free-field and Random incidence (also known as diffuse-field) corrections are available for most GRAS measurement microphones. These values are showing how…

The preamplifier is a device that takes the high impedance signal coming from the microphone capsules and converts it to a low impedance signal that can be...

We will explore the benefits and limitations of the CCP preamplifier and Prepolarized microphone technologies so it is possible to make a…

Prepolarized microphones have a thin layer of electrically charged material on its backplate. The electrons in this material will provide the polarization voltage needed by...

A random incidence corrector (aka diffuse field corrector) is an accessory that is placed on top of the microphone capsule. This is done in order to…

Any object that is placed in a sound field will cause a disturbance due to its size and shape. A microphone is no different. A standardized IEC-61094-4 WS2P ½” pressure measurement microphone has a…

Yes, it is possible if Low-noise microphones are used. Low-noise microphones are measurement microphones with very…

GRAS 146AE, 147AX and 147EB microphone sets (Figure 43) are the first microphones we released that are specifically designed to overcome some very specific challenges found in Automotive NVH testing. Here there is a list of some of their more…

A microphone capsule that is classified as a measurement microphone, as defined in IEC 61094 standard family, is of…

The output from a condenser microphone is a very high-impedance signal and is therefore very sensitive to the capacitive loads of cables. This makes it necessary to...

Just like with microphone capsules, there are also two main types of preamplifiers that are used together with measurement microphones. The difference between these two types lie in the…

TEDS (Transducer Electronic Data Sheet) is a set of electronic data in a standardized format defined within the IEEE 1451.4 standard. This data specifies what type of sensor is present, describes its…

Every ear simulator/coupler has a different design and calibration method. There are some ear simulators that can even be calibrated in different ways, by adding …

A measurement microphone that is stored in a controlled laboratory environment that was never exposed to challenging environments, shocks, drops or vibrations, can keep its…

Pistonphones and sound calibrators are instruments designed for sensitivity checking and calibration of measurement microphones. In order to do that, these instruments can…

No, 44AA and 44AB mouth simulators won’t fit inside a KEMAR Head. The KEMAR´s mouth simulator has a…

Yes, both RA0401 and RA0402 711 style ear simulators from GRAS are an improved version of the classic RA0045 and RA0045-S1 ear simulators. They fulfill all the specifications from a...

RA0403 and RA0404 Hi-Res ear simulators are not necessarily better or worse than RA0402 and RA0403 High Frequency ear simulators. Using RA0403 and RA0404 ear simulators can have…

Yes, it is possible. Active Noise Cancellation and Bluetooth headphones/headsets tend to have a “hiss” noise in quiet surroundings. This “hiss” can be detected via subjective testing, but when...

Standard/classic rubber pinnae (like GRAS KB0060/1 and KB0065/6) were originally designed for testing hearing aids or in-ear phones from communication devices with conical or cylindrical fittings...