The Model 3900 Dynamometer (Model 3900) is a full-sized machine specifically designed to evaluate Noise, Vibration, and Harshness (NVH) of brake assemblies for automotive and medium truck applications up to 11,300 Nm. This state-of-the-art machine incorporates a 186-kW motor capable of low speed brake drag protocols while utilizing a vehicle suspension fixture to accurately reproduce system NVH frequencies. To further duplicate on-road test conditions the suspension fixture is contained within a climatic controlled test enclosure. The test enclosure is designed as an acoustic free field chamber making the Model 3900 a perfect machine for research and development of brake system NVH. Additionally, the Model 3900 is a multi-purpose dynamometer that allows for performance brake testing. The dynamometer is fully capable to conduct all of the standard brake performance test procedures. Having one dynamometer that is qualified to conduct both NVH and performance tests can be advantageous in brake development.