Noise Neutralization

p>

The doorway to enter the hemi-anechoic test chamber for the Automotive Seating R&D Center in Faurecia’s new headquarters. Image courtesy of Eckel Industries.

In July, in the heart of the U.S. automotive industry, global automotive supplier Faurecia opened its new North American headquarters. The 278,000-sq.-ft. facility, located about 30 miles north of Detroit in Auburn Hills, MI, encompasses a high-tech research and design center featuring an anechoic test chamber designed and installed by Eckel Industries of Cambridge, MA.

Chances are consumers don’t give a thought to the noise and vibration emitted by the motor controls of the seats in their cars, unless they’re loud, grating or lurching. But the reality is that automotive manufacturers invest time and money in testing these parameters to ensure consumer comfort and meet industry standards.

Faurecia wanted to take its automotive seating noise, vibration and harshness (NVH) testing to the next level to achieve the highest industry standards. Because a large share of its global sales belong to premium automotive manufacturers, subjective “psycho-acoustic” benchmarks are crucial.

Having worked with Eckel in the past and knowing the company’s ability to meet standards beyond the norm, Faurecia went directly to the Eckel team to design and install a hemi-anechoic test chamber for the Automotive Seating R&D Center in its new headquarters. It is the largest chamber in any of Faurecia’s worldwide locations, and can accommodate an entire vehicle.

Eckel’s team of designers and engineers worked closely with Faurecia’s building contractor on the requirements for the room within which the chamber would be installed. The team also responded swiftly and deftly to ongoing requests for changes to the chamber layout.

The design process began in June 2013. In February 2014, Eckel got the call to head to Michigan to install the chamber, which has been operational since March. Faurecia began conducting testing in April as it transitioned employees and operations to the new headquarters.

“Eckel’s anechoic acoustic chamber design and installation teams were efficient and easy to work with,” reports Christopher Kus, project engineer and NVH specialist for Faurecia. “They were able to quickly supply quotes during each altered revision of the sound chamber layout. Installation timing was exactly as defined, and the finalized acoustic chamber has world-class quality.”

Faurecia Engineering Director Robert Parmann agrees. “Eckel worked very well with us and with our general contractor,” he adds. “Their exceptional planning, organization and collaboration helped to keep our total project on schedule. The final test chamber was completed on time, and exceeded the ISO specifications and our expectations.”

Exceeding the Standards

Faurecia’s products need to meet both automotive original equipment manufacturer (OEM) NVH standards, or preference rating specifications, and its own established consumer tolerance thresholds. During production of new vehicles, automotive manufacturers rely on Faurecia to test their seat frames and motor controls to achieve specific NVH goals. Accordingly, Faurecia required the new hemi-anechoic test chamber to meet the ISO 3745 standard for transmissibility, including a target base ambient sound level below 25 dBA (somewhere between rustling leaves and a whisper). The Eckel chamber exceeds the ISO specifications: It’s certified at 17 dBA.

Automotive manufacturers rely on Faurecia to test their seat frames and motor controls to achieve specific noise, vibration and harshness goals. Image courtesy of Eckel Industries.

Internally, the chamber measures 19 ft., 4 in. by 28 ft., 10 in., and 12 ft., 2 in. high. It features a 10-ft.-square vehicle door, a 7x3-ft. personnel door and an isolated floor that prevents external vibrations from being transmitted into the chamber. The walls, ceiling and doors are covered with anechoic perforated metal wedges, each measuring 34 in. long.

The chamber has a 100 Hertz cutoff frequency (the cutoff is the frequency at which the energy absorption drops below 99%, or the pressure reflection exceeds 10%). It also incorporates a 2,000 cfm silenced ventilation system. To meet Faurecia’s request for a distinguishing element — something that would make the chamber immediately recognizable as Faurecia’s — Eckel painted select anechoic wedges blue.

“Faurecia is a standout global automotive supplier, so it made perfect sense to give their anechoic chamber a look that reflects the company’s uniqueness and stature,” says Eckel VP Jeff Morse. “We’ve been privileged to work with them for many years, providing production line and laboratory test enclosures, and were thrilled when they selected us to build a state-of-the-art chamber at their new headquarters. We look forward to continuing to serve their acoustic design needs in the future.”

More Info

• Eckel Industries
• Faurecia