Qsources’ solutions are used worldwide by development engineers, consultants, researchers at institutions and universities. Our range of Infra-Qsources & Simcenter Qsources products can be used in a wide array of applications including architectural acoustics as well as industrial, technical or automotive applications.


Building acoustics encompasses the control of noise inside buildings. This includes isolation of sound transmission between rooms or sections of the building and the acoustic quality or sound characteristics of spaces. These factors are most important to consider during the design and construction phase as they can have an impact on general well being, health, communication and productivity.

Acoustic measurements are performed on completed buildings to optimize the isolation but also to identify the behavior of structural materials in their normal application environment. Studies are also used for verification of the predicted behavior from models.

Sound transmission across larger spaces can be controlled by measuring acoustic parameters such as reverberation time or speech transmission index (STI). The sound transmission through or across floors, partitions, venting systems or windows is typically measured on-site or verified by means of transmission loss.


Controlling sound quality, spectral balance as well as the ratio of early and late reflections which are influencing the natural character of music and speech intelligibility are particularly important in spaces such as concert halls, recording studios, lecture halls and theaters.

Factors which can influence the quality of sound or transmission across spaces include: the angles and dimensions of the reflecting surfaces, their corrugation, the reflective and scattering properties of the materials, the presence of audience, and the open volumes in spaces.

Measurements of reverberation time, speech transmission index (STI) or impulse responses are performed to optimize sites and identify the reflective behavior of surfaces and materials in their normal application environment or for verification purposes.

Next to measurements in performance sites, general room acoustics also acompasses measurements in apartment buildings, houses, work places and offices. Room acoustics influences the well being being of inhabitants and their effectiveness at work.


Road noise and railway noise belong to the most disturbing and the most investment-intensive noise issues. Railway- and subway- stations are notoriously loud and often suffer from poor intelligibility of announcements.

Noise mapping and noise monitoring are widely used techniques for the prediction and assessment of traffic/railway noise. On-site measurements with powerful monopole sound sources allow verification measurements. Measurements can target local reflection measurements to verify the surface parameters, like absorption coefficient and scattering, as used in models. Furthermore, source controlled measurements on longer distance attenuation allow the verification of the longer distance prediction ability of models.

These studies lead to improvements of noise reducing solutions during construction phase or in a later phase by determining the optimal measures such as road barriers. These solutions can improve the quality of live for those living and working around any traffic line.


Industrial machinery and their instruments such as fans, panels, engines, rotors and so on can cause a lot of noise. Excessive noise has become one of the leading occupational hazards and may lead to hearing loss.

The determination of sound power according to the ISO 3741 to ISO 3747 range provide a practical base for the limitation of noise emission. Manufacturers of machinery, enclosures, barriers and absorption materials can work to the desired specification at medium and higher frequencies. This is based on sound power estimation and verification. Determination of the sound power emission in an acoustic chamber, or in free-field are often impossible for large machines, or even for smaller machinery which depend on infrastructure for normal operation. Therefore, on-site measurements in non-ideal acoustic environments are required.

The usage of a sound power reference source can be used to determine sound power emission in-situ, as an alternative to sound intensity scanning or other complex and more demanding techniques.




A wide range of techniques are needed for limiting noise emission, achieving acceptable cabin noise, reducing vibration for higher precision or controlling vibration fatigue.

Certain measurements, such as airborne noise isolation across large ships, can be addressed with energy analysis based techniques. Similar to the technique used in building acoustics. The Infra-Qsources range provide opportunities for these applications because of the small dimensions and controlled noise radiation.

Other measurement techniques require products which can also be used for automotive applications such as suspension of propulsion systems, modal analysis and transfer system. The integrated sensors in the Simcenter Qsources sound sources, and the self-supporting and self-alignment suspensions in their shakers are a major advantage for these type of tests.

There are special requirements in these application areas, related to flow, temperature, level, etc. which may be addressed with custom-made Qsources products such as QindW, a flush reference source which was developed for a windtunnel application.


Occupants in vehicles tend to be very close to loud sources of disturbance such as combustion engines, whining gears, hydraulic pumps, road-tire interaction as well as turbulent flow around the cabin. There is no space available for thick heavy noise isolating structures inside or around the vehicle. Electrical vehicles with light weight structures bodies especially require complex engineering and measurements leading to acoustic comfort.

There have been a lot of developments in automotive NVH in past years including elaborate testing procedures. Common measurements include a combination between tests & model analysis for materials and components, NVH testbeds for subsystems, diagnostic measurements on complete vehicles in natural operation, dynamic load identification, model verification/correlation testing, etc.

Qsources has developed specialized sound sources and shakers for automotive testing. The Simcenter Qsources range is extensively used in NVH procedures such as Transfer Path Analysis (TPA), FRF measurements, vibro-acoustic transfer functions, airborne sound quantification and modal analysis.