Vehicle acoustics

Solutions for acoustics and vibration control technology

Projects in vehicle and test bench testings are always challenging and require technical expertise, especially when it comes to air conditioning and acoustics. This is not least because of the continuous development of more efficent engines and power train systems and the resulting changes in climate and acoustics testing. IPETRONIK has many years of experience as well as the required know-how to conduct measurement processes, test and developments to your full satisfaction.

Acoustic optimization

Acoustics play a vital role in the automobile series development. IPETRONIK is your experienced partner in this field of engineering. Especially concerning the optimization of HVAC acoustics. This becomes more important because of lower background noise levels of new generation of powertrain. As a first step, we record the status quo, i.e. the vehicle noise as well as all relevant parameters for stimulation and transmission with our extensive measurement equipment. A comprehensive analysis then identifies undesired noise components in order to develop corrective actions. Usually, vehicles are tested in a climate acoustic chamber using the same measurement equipment as on aggregate acoustics test benches. A typical vehicle test includes the following:

  • Simulation of real-life test conditions with ambient temperature and relative air humidityRecording of the thermodynamic parameters (temperatures, pressures, rpm, etc.) vibroacoustic parameters (pulsations in the refrigerant piping, vibration, airborne noise, etc.), as well as the digital bus data of the vehicle (CAN, LIN, FlexRay)
  • Repetition of the measurement process in acoustically relevant operating conditions

The combination of IPETRONIK measurement hardware and software guarantees the smooth interconnection of the on-board system’s digital bus data streams and the applied measurement instruments.


Aggregate acoustics

As the core of the refrigerant circuit, the refrigerant compressor produces the required cooling performance but also undesired noise through vibration and force excitation airborne noise emission, as well as pulsations in the refrigerant piping.

The innovative IPETRONIK aggregate acoustics test bench records the vibroacoustic stimulations at every interface and the vehicle operating parameters with the help of microphones, load cells, acceleration and pulsation sensors, as well as measuring sensors for thermodynamic values.

With our load unit IPEload, the load and operating conditions of the refrigerant compressor can be simulated in a precise and repeatable way for high and low load. In addition, this allows us to represent partial load conditions with swashplate angles of the medium control range during an rpm ramp and precisely observe predetermined values for pressure, temperature, superheating, and mass flow. Empirical values are available for belt-driven compressors and electric scroll compressors of the refrigerants R134a, HFO-1234yf, and R744 (CO2).

Artificial head

Airborne noise is usually measured with microphones that can be placed anywhere in the room, the amplitude of the sound pressure being the essential measurement parameter for the description of a sound field.

Since this parameter cannot represent all the important criteria of the human auditory perception, so-called binaural microphone arrangements have become established. With two microphones and a separating body similar to a human head, the recordings provide very authentic listening experiences when replayed with headphones. The IPEacoustic head combines both of these approaches by using an innovatively shaped separating body and a third microphone.


The two lateral microphones provide the characteristic database of a separating body stereophony. The wedge profile of the head creates an additional, acoustically neutral measurement position to record the sound from the front and the sides extensively uninfluenced. One major advantage of this method is the synchronicity of the binaural and the neutral sound recording in one place.

Technical details:

  • Wedge-shaped head with binaural microphone arrangement
  • Additional third microphone placed in acoustically neutral position
  • Complete with torso and inclinable head
  • Easy handling
  • Equipped with ½“ microphones (IEPE or 200 V supply)
  • Compatible with all common acoustics measurement systems
  • Standard front end: IPETRONIK Mx-SENS2 4
  • Standard software: IPEmotion with acoustic module (incl. several export formats)
  • Optional Noise-free high performance PC integrated in the IPEacoustic head body
  • Dimensions: W 38 cm x H 76 cm x D 34 cm
  • Weight: approx. 15 kg

Climate acoustic chamber

The climate acoustic chamber simulates the ambient conditions of a vehicle regarding temperature, relative air humidity, and radiant heat. The semi-anechoic room allows us to measure vehicle noise only occurring under extreme load conditions of the HVAC system.

In addition to acoustic measurements, our range of services includes cool-down tests and fill quantity determination. For all these tests and measurements, we use our well-proven high-performance measurement equipment, gaining precious experience in the process to further develop our hard- and software.

Location Baden-Baden

  • Usable dimensions: 6.5 m x 3.5 m 2.9 m (L x W x H)
  • Temperature range: -20°C to +50°C
  • Humidity control: 20 % to 70 % relative moisture within the temperature range of +10°C to +50°C
  • Air circulating volume flow: up to 23,100 m³/h 32 km/h)
  • Acoustic measurements: up to 10,000 m³/h
  • Sun simulation with infrared: up to 1,200 W/m² (also usable at sub-zero temperatures)

Location Eichstaett

  • Usable dimensions: 9.6 m x 5.8 m 3.5 m (L x W x H)
  • Temperature range: -5°C to +50°C (expendable up to -20°C)
  • Humidity control: 20 % to 70 % relative moisture within the temperature range of +10°C to +50°C
  • Air circulating volume flow: up to 46,200 m³/h (64 km/h)
  • Acoustic measurements: up to 10,000 m³/h
  • Sun simulation with infrared: up to 1,200 W/m² (also usable at sub-zero temperatures)
  • Certified semi-anechoic room according to DIN 3745
  • Integrated freewheel hubs system