Reassuring vault-like door sound is the ideal for the Volvo Cars' noise team
The Volvo V70 and S80 ranked among the ten best cars when Swedish motoring magazine Vi Bilägare tested noise levels in 35 car models. A great result for Volvo Cars' sound and noise experts and engineers who worked closely together to improve the sound environment.
A dedicated music-lover can spend thousands on an audio system that gives the most perfect balance in the music of his or her choice. That is exactly the way the engineers at the Volvo Cars NVH centre (NVH stands for Noise, Vibration and Harshness) work to create the right sound environment inside the car. This does not mean that the passenger compartment has to be clinically silent, but rather that the right sort of sound should be heard at the right volume.
Changes and developments in working methods throughout the Volvo Car Corporation mean that the NVH centre enters the process earlier in the new-car project, and that cooperation with its engineers is closer than ever before. As a result, the results are also better than ever before. Together with the engineers, the NVH centre has above all examined what improvements can be made to insulation, absorbents and mouldings. Calculations early in the overall process, the design of chassis components and noise from the engine are also factored in and balanced against other properties during the development phase.
"We see a major improvement in the Volvo V70 - the compromise between the car's various characteristics that we must always make was highly successful," says Anette Garnemark, systems analyst noise and vibration.
The work is carried out very systematically. Problems are identified early on so everything is right from the very beginning.
This successful working method has attracted a lot of attention. A survey was recently carried out by motoring magazine Vi Bilägare which measured the noise levels in 35 different car models. The Volvo V70 and S80 were among the ten best. Other car magazines such as Teknikens Värld and Aftonbladet Bil also praise the low noise level, especially in the Volvo V70.
Irritate, inform or impress
NVH divides noise into three different categories: those that irritate, inform and impress. The first category should preferably be entirely absent. The second includes a certain degree of engine noise, for instance, so the driver knows the engine is running.
One example of sound that impresses is the noise a car door makes when it is shut.
"We want it to sound reassuring, like the door of a vault," explains Anette.
The 60 or so staff at the NVH centre set requirements, make calculations, test-drive pre-series cars, listen and assess, and finally suggest improvements and recommend how best to implement them. Subjective assessments are combined with objective tests that measure the noise level. Maximum noise levels that are heard outside the car are regulated by legislation but for the interior environment, it is Volvo Cars' own requirements that apply. In a nutshell, they stipulate that the perception of a Volvo should always be premium - even for the ear.