Buzz, Squeak and Rattle Testing
Case Study – One Stop For Buzz, Squeak and Rattle Testing
Buzz, squeak and rattle testing is the new advanced technique used to resolve annoying noises in vehicle interiors which occur when incompatible contacting material pairs move in relation to each other. This movement is frequently caused by vibration road load inputs or flexing of the the vehicle body. The result is noise often referred to as buzz, squeak and rattle (BSR) or squeak & rattle (S&R).
Buzz, squeak and rattle issues are notoriously difficult to troubleshoot and repair once a vehicle has left the assembly plant. To test for BSR or S&R issues on the component or system level, development and design engineers measure the sounds emitted by their products while the product is excited with vibration inputs provided by an extremely quiet shaker inside of a quiet sound chamber.
Paragon Systems is one of a handful of independent labs in North America with this buzz, squeak & rattle vibration testing capability and is the only facility in Canada. The core of the system is an extremely quiet (<30 dBA/1.2 sones while operating) electrodynamic shaker, the best-in-class MB Dynamics Energizer Black.
Don’t be fooled by laboratories advertising that they can do buzz, squeak and rattle testing by shutting off the cooling blower to their electrodynamic shaker. These types of cobbled-together setups are hard pressed to achieve background sound levels lower than 50 dBA and then only for very short periods of time due to shaker overheating.
The MB Dynamics Energizer Black and our quiet chamber comply with the requirements of the most demanding BSR test in the industry, GMW14011. The Energizer Black shaker is mated to equally quiet MB Dynamics horizontal moving table which permits excitation of the product in the two lateral axes.
In addition to shaking a product and measuring the noise and acceleration response output, the system can be configured to examine the squeak and itch characteristics of door sealing systems. Squeak and itch is caused when a door seal element moves in relation to the mating surface on the door frame.
The sound and vibration software and multi-channel data acquisition system is capable of simultaneously recording data from microphones surrounding the product as well as from lightweight (5 gram) accelerometers mounted to the product. Sound and vibration data can be correlated on the same time base. This is an invaluable tool for troubleshooting buzz, squeak & rattle issues on automotive assemblies.
Just like the one-stop service we provide for our vibration testing clients, we also have the in-house capability to design and build the specialist quiet BSR fixtures necessary to bridge the interface between your device and the BSR shaker while still maintaining the very quiet environment.
Buzz, Squeak & Rattle Shaker
- Frequency Range: From DC up to 2,000 Hz
- Displacement: 50 mm maximum
- Product Weight: 34 kg (90 kg with supplementary support)
- Operating Background Noise (typ): < 30 dBA, 1.2 Sone (N10 Zwicker Loudness)
S&R Vibration Controller
- Input Channels: 2 maximum
- Background Noise (typ): < 24 dBA, 1.0 Sone (N10 Zwicker Loudness)
- Noise Criteria (NC) rating: < NC15
- Interior Dimensions: 3.39 m L x 2.17 m W x 2.31 m H
- Door Opening: 0.85 m W x 2.07 m H
Sound + Vibration Measurement & Analysis System
- Sound Inputs: 4 maximum
- Vibration Inputs: 10 maximum
- Typical Measurements: Sound Pressure (dB(A)), Zwicker Loudness (ISO 532), 1/nth Octave, FFT
- Ford Simple Sound Quality Tool (SSQT)