Automotive Testing Facilities

IAC Acoustics can provide a number of different chambers to suit the needs of the automotive sector. Below is a list of other facilities available from IAC Acoustics:

Powertrain NVH Chambers

Powertrain testing is typically carried out inside a hemi-anechoic chamber to ensure high acoustic absorbency. A typical layout for powertrain test cells is with 2 independent dynamometers sitting outside of the test chamber, leaving only the engine and gearbox inside the hemi-anechoic room. IAC powertrain chambers allow functional testing of various powertrain and transmission types in a virtual vehicle environment.

  • Acoustic and vibration performance (acceleration, deceleration)
  • Optimisation of the powertrain and driveline components (engine accessories, shafts, intake system)
  • Base calibration of control units (ECU, TCU etc.) to improve the NVH performance

The flexible design of IAC powertrain test cells allow the installation of various transmission types:

  • Manual transmission
  • Automatic transmission
  • CVT transmission
  • Dual clutch transmission
  • Hybrid transmission

The aim of this test rig is to perform tests on FWD and RWD Power Train systems for NVH R&D purposes.

Driveline Chambers

Driveline chambers are similar to powertrain test cells,except they have no acoustic treatment. Driveline chambers typically measure engine performance such as economy, timing, pressures and power. As no acoustic measurements are taken in this type of chamber, there is usually no need for acoustic linings to the inner walls. The exception to this may be if there are other acoustic-sensitive tests going on in adjacent rooms.

Modal Analysis Rooms

Modal analysis facilities are used to measure the resonance and tone of bodywork panels on a vehicle.

Panels are struck with differing degrees of force and the resulting resonance measured. This type of testing is used to ensure panels do not excessively vibrate, causing unwanted noise. Panels which are found to have a high degree of resonance can be treated with additional supports and strengthening to overcome the problem.

Like listening rooms, IAC modal analysis laboratories are constructed from Moduline™ panels to isolate external noise from the facility. The room is then treated with IAC Varitone™ panels to tune the space for an optimum amount of absorption.

Shake & Rattle Facilities

Shake and rattle facilities are typically used at the end of a production line before a vehicle leaves the factory. This is a final acoustic test to ensure there are no panels which squeak or rattle. Small, unwanted noises within a vehicle cabin are one of the main reasons for returns to dealerships, post purchase and this test helps to avoid dissatisfied customers.

IAC Acoustics can provide a turnkey service for shake and rattle rooms providing the hydraulic 4-post test rig in addition to the acoustic treatments to the room to ensure no interfering sound transmission from other areas of the production facility.

Airbag Acoustic Test Facilities

Testing airbags is a particularly noisy and dangerous procedure. Dealing with controlled explosions and instantaneous noise levels in excess of 140 dB, airbag testing can have a detrimental effect on the health of staff working in the vicinity if it is not managed correctly.

IAC Acoustics has experience in providing airbag testing chambers for both in-vehicle and off-vehicle testing.

Due to the levels of noise control required, airbag facilities are typically of a twin-wall Moduline™ construction with a large air gap between the two walls.

Quiet Rooms

Quiet rooms are similar to VSAC’s, except without a chassis dynamometer. Quiet rooms are typically facilities for taking acoustic measurements around a stationary or idling vehicle. Noise from components and tangible areas of a vehicle that a consumer will interact with such as handles, switches, door closures and windscreen wipers are measured in quiet rooms.

Due to the measurements being taken, quiet rooms need to be isolated from any other noise sources. Typically manufactured from acoustic walls and ceilings, the addition of anechoic wedges ensures minimal transmission of sound from other areas of the facility entering the test chamber.

Background noise typically ≤ 20 dB(A).

 

ISO 5130:2020 Anechoic sound chambers

ISO 5130:2020 describes the measurement methodology for determining the sound pressure level of stationary road vehicles. This standard is typically applied in semi-anechoic or fully anechoic chambers to minimize external noise effects and enhance the precision of the measurement results. The vehicles are in a stationary condition while their engines are operated at defined RPMs to acoustically simulate real operating conditions, such as idle or stationary operation.

The test setup includes microphones positioned at specified distances from the exhaust or other relevant noise sources, in accordance with the standard’s requirements, to ensure accurate and reproducible measurement values. Measurement chambers specifically designed for ISO 5130, such as IAC chambers, provide a controlled environment necessary for the precise recording of sound pressure levels. This ensures reliable verification of compliance with legal noise limit values.

The measurement chambers are tailored to accommodate various vehicle types and engine configurations, allowing manufacturers the flexibility to conduct noise measurements as part of vehicle development. Due to their outstanding sound insulation and absorption, ISO 5130-compliant test facilities provide consistent and robust data for determining the stationary noise emissions of vehicles.

 

  • Cut-off frequency <100 Hz
  • Background noise shall be at least 10 dB below the A-weighted sound pressure level to be measured
  • 3 m radius from the microphone location and any point of the vehicle
  • ISO 26101:2017 Acoustics — Test methods for the qualification of free-field environments