Practical Considerations for DFAN Testing

On the heels of a string of successful test campaigns, a recent lessons learned meeting had our engineering team reviewing and reflecting on ways to keep improving our operational performance and the quality of service that we’re able to provide. While we enjoy presenting at conferences and working on groundbreaking acoustic research, the services and sales our team provides with our Neutron™ System are really where the rubber meets the road when it comes to performing a safe, accurate, and successful test campaign. Building off part 1 from one of our most recently published papers, I thought it would be interesting to share some of our insights as we prepare for another run of large-scale Direct Field Acoustic Noise (DFAN) test services.

While we spend a lot of time discussing the quality and performance of our hardware systems, one of my most frequent sayings of the past few years has been, “A product is only as good as the people behind it.” In one of our recent large-scale DFAN tests, we deployed not only 48 Neutrons but also achieved synchronized technical performance from nearly a dozen of our team members. For every large test, there are engineers and technicians who need to perform their jobs safely and consistently throughout the entire test campaign. To fulfill our mission of providing complete 360-degree support for our customers, we provide not only DFAN testing experts but also specialists in structural engineering, data acquisition, test operations, and highly experienced test conductors.

This deep bench of experienced team members, combined with the simplicity of the Neutron™ System not requiring complex customization for each configuration, allows us to support multiple programs in various locations around the world with ease. Delivering quality speakers is just one part of the equation; having skilled engineers and qualified technicians involved helps ensure that every test runs safely and successfully, contributing to a complete DFAN campaign.

Another recent topic our team worked on centered around helping our customers understand how a very large Neutron™ System deployment would affect the concrete floor in their facility. With our upcoming deployment for one of the largest DFAN tests in history, every aspect of system operation and performance needs to be reviewed meticulously—not just by our team of experts, but also by several key decision-makers—experts in their own right—who support our customer and our host facility.

There were two main concerns when it came to placing a large DFAN system from the standpoint of the flooring: weight distribution and total weight supported. The legacy approach of using concert line array systems can severely impact the construction of typical concrete floors because each column distributes its weight on a limited number of “feet.” Furthermore, given the massive number of enclosures required, the total weight of the system can significantly impact a facility floor. Hence, our engineering team devoted considerable time during the design phase of the Neutron™ device to reducing its weight through acoustical design improvements and increasing the bearing area of the device to ensure that the weight of each column would not become a set of concentrated point loads when deployed in large configurations.

Two practical benefits of our design work on weight and loading were very clearly realized. Thanks to its increased surface area and 4-5x reduction in the number of enclosures required for a test versus concert systems, the Neutron™ makes for a much safer test system from the standpoint of the facility floor surfaces. When compared to legacy approaches to DFAN testing, the Neutron™ can reduce the pressure each column places on the floor by a factor of 50x. Additionally, because the system works on the principle of exceptional efficiency and power, fewer devices are needed. We saved one customer nearly 20,000 lbs of total weight versus their previous test solution for the same size of test article. That’s a lot more sound for a lot fewer pounds! (And fewer trucks on the road, lightening our environmental impact as well.)

A third and final key point—and one we’ve talked about in previous articles—is that we keep seeing how pre-planning is paramount for performing a successful DFAN test. This includes not only system preparation but also a significant amount of documentation and paperwork. For a Neutron™ acoustic device heading to a test, it is important to note that the test campaign can begin weeks before the actual test itself. Technicians at the ARS warehouse verify the acoustical performance of the Neutron™ as well as perform a final QA check, including cleanliness and cosmetic checks. If the DFAN test is to be performed in a clean facility, ARS technicians will perform a final cleaning of the unit before encapsulating it in plastic to maintain cleanliness. ARS has general internal guidelines for system cleanliness, but we often work with the client to tailor our cleaning program to match their requirements. Every part of the ARS System that must be placed inside the cleanroom is cleaned using similar methods. The goal of this cleaning is to reduce or eliminate the cleaning burden as the system is moved into the customer’s facility. Ultimately, this attention to detail will save time during facility test preparations and test execution.

The cleaned and packaged system is then loaded onto semi-trailers that have also been thoroughly cleaned. One of the benefits of our facility being both modern and clean is that we’re able to maintain our cleanliness levels through loading onto the truck. It is inevitable that some dust will settle onto the system, especially if they must be transported long distances. Luckily, the system is already encapsulated in plastic to ensure the system will be clean upon arrival at the customer facility.

While paperwork, cleaning, and weight savings might not be the “coolest” aspects of our job, they are crucial. Our team’s dedication to maintaining a consistent level of quality and excellence enables us to provide the outstanding customer service and successful tests that our company has become known for today. With several large test campaigns coming up, I’m excited to return and continue growing our base of knowledge with more practical lessons learned and successful test campaigns completed.