Qmed Low Frequency Monopole Source


The Simcenter Qsources hardware low frequency monopole source has been designed to measure vibro-acoustic transfer functions in and around vehicles. The sound source level in combination with the frequency range makes this source a versatile measurement device designed to meet the needs of noise, vibration and harshness (NVH) research and development departments. The negligible diffraction makes it an accurate omnidirectional sound source up to 2,000 hertz (Hz). This source also allows you to measure typical vibroacoustic body noise transfer functions reciprocally, which is valuable information for vehicle body development. It can excite the passenger and trunk cavity to measure scaled acoustic transfer functions. These frequency response functions (FRFs) can be used to perform acoustic modal analysis. These sources are compatible with the latest standards for acoustic modal analysis, which propose multiple sources in the cavity without the disturbances associated with traditional low-frequency sources. Another application of the measured FRFs is for indoor pass-by-noise engineering. Acoustic frequency response functions between indoor microphone positions and microphone positions at dominant sound sources in and around the vehicle is acquired from 30 Hz up to 1,000 Hz. The reference sensor is integrated in the source and measures the volume displacement. The sensor is independent from the acoustic environment in which the source is used. Sophisticated electronics are integrated.


  • Compact volume acceleration sound source for scaled acoustic driven frequency response functions
  • Near to perfect monopole behavior due to patented driver configuration 
  • Drivers and integrated sensors for a source level signal with long-time stable calibration 
  • Large stroke piston drivers for high sound pressure level in smaller spaces, between 5 and 1000 Hz for acoustic transfer and acoustic modal analysis
  • Highly suitable for reciprocity based vibro-acoustic frequency response function measurements in cars, truck cabins, etc. for the 30 to 1000 Hz range
  • Built-in overload protections