Over the years, many of our customization projects have turned into industry standards. By tailoring both technical specifications and form factor, as well as carefully considering where, how, and by whom the microphone will be used, we’ve succeeded in creating a number of bestsellers. Here are a few of our favorites.
GRAS 146AE
A lab quality microphone designed for the real world 
The ruggedized GRAS 146AE ½″ free-field microphone was developed as a direct response to insights and suggestions
from close collaborators in the automotive industry. Their main challenge? All the mics they used were developed for lab use. But acoustic testing of cars takes place in less pristine and controlled environments – meaning their mics would get dropped and break or get clogged by oil and dust. On top of that, most mics on the market were developed for one specific scenario, e.g., indoors, outdoors, high or low temperatures. This meant that acoustic engineers had to switch mics again and again. Addressing these, and many more, issues one by one, resulted in the ruggedized GRAS 146AE. Tough enough to survive and perform in the majority of all NVH acoustic applications.
GRAS 147AX
An elegant solution to a sticky issue
Over the years, by closely collaborating with our customers and engaging with their acoustics teams, we have developed unique solutions that have since become industry benchmarks. One notable example is the GRAS 147AX CCP Rugged Pressure Microphone, designed specifically for motor sound measurements. Prior to its introduction, acoustics engineers in the automotive industry had to improvise engine bay sound measurement setups using regular free field microphones and miles of duct tape. This process was time-consuming and compromised the reliability of repeated testing. Recognizing this issue, our development team responded with a rugged, surface-mounted microphone featuring a magnetic base, enabling effortless mounting – an instant classic in the industry
GRAS 147EB
Developed for 10,000 miles of rough treatment
The wheelhouse of a car is extremely hostile to regular test microphones. Think rain, salt, snow, and ice, then multiply by 10.000 miles of test drives. The result is lots of stops for replacing broken microphones and recalibrating your test setup. That’s why we developed the GRAS 147EB in collaboration with our friends at Volkswagen. The 147EB CCP X-Rugged Microphone Set is an extremely robust microphone specially designed and optimized for on-road brake noise testing – in all weather conditions. Waterproof, oil and dust-resistant, and temperature stable, all you need do is replace or clean its grid and windshield once in a while.
GRAS UTP
High precision, low profile
Measuring the sounds of the airflow and turbulence around an aircraft as it moves through the air (or gets tested in a wind tunnel) has always been a challenge. Unless your test microphones are flush against the surface of the aircraft, all they’ll pick up is the noise generated by themselves. Only very small, thin, and aerodynamically correctly shaped sensors can do the job. That’s why our close collaborators at Airbus gave us a very specific challenge: To develop a test microphone no thicker than 1 mm. So we did. The solution was the UTP family of Ultra-Thin Precision microphones. The UTP microphones combine the high precision and reliability of GRAS measurement microphones with the need for extremely low-profiled (less than 1 mm) microphones with minimum turbulence influence. Challenge accepted. Challenge met!
GRAS 46DE
The world’s smallest measurement microphone set
Here it is: The world’s smallest measurement microphone set – with a microphone capsule the size of a match. When it comes to precision sound measurements, size matters – and even a small microphone can cause big trouble. That’s why GRAS decided to develop the 46DE, a microphone set that at ⅛″ is almost invisible. Because of its small size and low sensitivity, 46DE is ideal for measuring high frequencies and high sound pressure levels. Furthermore, the small size allows measurements in confined spaces not previously accessible. There really wasn’t a market for such a small microphone, but we decided to make one just to prove that we could. Today, this little innovation project has become a big seller. Developing and producing something so small was a huge challenge, but the GRAS team delivered – and the user feedback is making it worth the effort.
GRAS 47BG-FV
Designed for tight spaces and high pressure
The GRAS 47GB-FV has been specifically designed for use in scenarios where flush mounting is required. It is optimized for acoustic measurements of a sound source at a boundary or wall; in which case the microphone forms part of the wall and measures the sound pressure on the wall itself. The 47GB-FV can be used in any flush-mounting setup, but it has several additional design elements that make it the perfect microphone for mounting where the distance between microphones must be very small or the cavity behind the measurement wall provides very little space for microphones and cabling.
EQset™ technology
Microphones with EQset technology all have a uniformly fixed sensitivity and flat curve. This reduces measurement uncertainty and greatly simplifies microphone setup, monitoring, replacement, and corrections. With EQset technology, everything can happen quickly and easily without any individual microphone adjustments or corrections. The simplification of setup and other tasks saves both time in the setup itself and time in operator training. The first microphones with EQset technology on the market are GRAS 40PM & 40PM-1. They are designed for use in production line environments, where they provide a costeffective, easy-to-use, error-resistant, and environmentally stable alternative to traditional production line test microphones.
