Automotive Audio Measurement
Any car audio, any measurement
SoundCheck offers simple, fast and accurate automotive audio measurement, from individual speaker components to complete in-vehicle infotainment and telematics systems. With interfaces to connect via Bluetooth, Lightning, USB and with individual MEMs devices, as well as analog connections, SoundCheck easily handles the complexity and demands of audio testing in today’s vehicles.
Automotive audio measurements include
- Speaker/system response
- Speaker/panel buzz, squeak and rattle
- Bluetooth audio performance
- Head unit and amplifier response & THD+N
- Microphone/microphone array response.
- Active noise cancellation effectiveness
- Spatial reproduction accuracy
Automotive Audio Measurement Test Configurations
There are many different automotive audio test configurations, depending on the nature of your test. Signal maybe captured by a single microphone, pair of microphones, 6-mic array or even a head and torso simulator, depending on your measurement requirements. Additional components such as Bluetooth interfaces my be added to get signals in and out of the head unit. Audio interfaces vary according to the number of channels. Below are some examples of common configurations, but there are many more possibilities. Please contact one of our engineers for guidance.
End of line multi-speaker test using a single microphone in the center of the car
Bluetooth in-car speaker test using a 6 microphone array to represent a person in the drivers’ seat
Bluetooth in-car microphone test using a head and torso simulator
Automotive Audio Measurement Software – The SoundCheck System
SoundCheck’s modular combination of hardware and software for automotive audio measurements is cost-effective, flexible and expandable.
At the heart of the system is the SoundCheck software. Powerful, fast and accurate, its scalable design allows it to perform in the field and simulation laboratory as well as the end of the production line.
Complete flexibility in stimulus choice enables any test signal (even music) to be used as stimuli. Virtual instruments offer the functionality of stand-alone hardware on your laptop. Advanced algorithms and powerful post processing options allow a wide choice of analyses and mathematical operations. For example, using a common 6 measurement microphone array, it is possible to measure sound power, time delays, spatial envelopment and both tonal and stereo balance. Alternatively, the response of a telematics microphone array to a person in the driver’s seat both with and without background noise can be evaluated. Documentation options range from comprehensive Microsoft Word or Excel reports to simple pass/fail outputs or automatic database writing.
Repeatable, automated tests are quickly and easily created, modified and saved using the simple point-and-click interface. Complex sequences can be developed to meet specific automotive test requirements, for example performance of active road noise cancellation, microphone directivity and spatial reproduction.
In addition to interfacing with the audio measurement hardware (audio interface, HATS, microphone, coupler etc.) the software can also control the vehicles head unit to adjust L/R and fader balance.
SoundCheck also fully integrates with the Mentor A2B interface for testing automotive audio connected via the Analog Devices A2B digital bus. The Mentor Analyzer, which handles the transmission of signal in to and out of the bus, is viewed as an ASIO interface by SoundCheck, enabling SoundCheck to read/write to the device and therefore analyze any transducer connected to the A2B bus.
SoundCheck Multi-channel RTA graph for automotive Max SPL measurement showing the results from 6 microphones as well as the average (black line).
Automotive Audio Measurement Hardware
AudioConnect 2™: A USB-powered high-precision compact audio interface with built in headphone amplifier and power supply for 2 microphones. This is a very cost-effective approach for basic automotive testing.
AmpConnect 6×2: A high-precision multi-channel audio interface with 6 input channels to support a 6-mic array and 2 output channels. It offers sample rates up to 192kHz along with microphone power, full TEDS support, impedance measurement and digital I/O in a single USB-connected unit.
AmpConnect 621: A high-precision multi-channel audio interface with 6 input channels to support a 6-mic array and 2 output channels. It offers sample rates up to 192kHz and includes an amplifier output, along with microphone power, full TEDS support, impedance measurement and digital I/O in a single USB-connected unit.
Halo 6-Microphone Array: A low-cost microphone holder with integrated bubble level for precise positioning to AES TC-AA guidelines.
SCM Measurement Microphones: Rugged and cost-effective 1/4″ microphones available in 2 sizes. The perfect companion for the 6-microphone array,
Automotive Test Kit: All the hardware you need for automotive test in a rugged carry case. Includes Halo 6 microphone array, 6 SCM-4 measurement microphones, stand, cables and AudioConnect 6×2 audio interface. Just add SoundCheck for a complete automotive test system.
SoundConnect 2™: A 2-channel microphone power supply (SCM, IEPE, 200V polarization) ideal for vibration measurements or applications where polarization is required.
BTC and BQC Bluetooth Interfaces: Designed for R&D and production respectively, these interface any Bluetooth device to SoundCheck, offering full control over all Bluetooth protocol settings and explicit control over the CODEC choice and transmitter power. The BQC is USB powered for easy on-road testing.
Also available : MEMS interfaces, speakers, current monitors, 3rd party hardware including Head and Torso Simulators (HATS), and more.
Examples: How do our Customers use SoundCheck for Automotive Audio Measurements?
These are just some of the automotive audio measurements that our customers are making:
- Final audio QC check on car including end of line distortion test to ensure no Buzz, Squeak and Rattle from the audio system
- Voicing audio system to the car including speaker positioning and equalization of the system for correct tonal and spatial balance including L/R and front/back balancing
- Incoming QC on MEMS microphones to be embedded in car
- Microphone positioning and directivity measurement
- On-the-road tests to evaluate active road noise reduction
More information? See the right sidebar to view detailed information about relevant test sequences, white papers, webinars and more about automotive audio testing.
In-car measurement of active road noise reduction using SoundCheck with the USB-powered AudioConnect
Recommended Equipment for Automotive Audio Test
Software
SoundCheck Basic (1000) for production or SoundCheck Advanced (1103) for R&D
Optional Software Modules
2019: Intermodulation (IM) & Difference Frequency (DF) distortion, including 2-tone stimulus
2021: Transfer Function
2024: 8 Channel system
Hardware
Automotive Test Kit (components including Halo 6 microphone array, SCM microphones, AudioConnect 6×2 and Bluetooth Interfaces also available separately).
Specialty Automotive Audio Measurements
There are many different types of automotive audio measurements. Expand the sections below to learn more about making measurements via Bluetooth, Max SPL measurements, impulsive distortion, Buzz Squeak and Rattle measurements and more. Also see the speaker and microphone testing section of the website for details on automotive audio component test for production and incoming QC.
Automotive Max SPL Measurements
Automotive Max SPL measurements enable a comparison of how loud an infotainment system can play in a car and is often quoted in specifications. However, it is important that measurement of this characteristic is standardized to offer meaningful comparison. Learn more about the AES’s efforts to standardize this and how to implement these measurements in SoundCheck. Read More >
Buzz, Squeak and Rattle Measurements
Buzz, squeak and rattle noises caused by the car’s audio system are typically caused by manufacturing defects in the speakers, such as transient distortion caused by loose particles, and loose wires or panels that vibrate when the speaker is played at high volume. These faults are easily identified by a combination of harmonic distortion (conventional or perceptual methods) and transient distortion measurement techniques. Read More >
On-road Automotive Measurements
It is often necessary to make audio measurements in a car while driving, for example for evaluating road noise and noise reduction systems, measuring infotainment system characteristics that may change with background noise such as frequency response, and assessing hands free communications systems in real-world conditions such as POLQA measurements. Learn more about test configurations for on-road measurements. Read More >
Connecting to Car Audio
One of the challenges with Automotive testing is connecting to the car audio system to get test signals in and out, whether you are testing the speaker and need to play a test signal out the car stereo, or whether you need to capture the response of an on-board microphone. Learn more about how to connect SoundCheck to your car’s infotainment unit via Bluetooth, USB drive or A2B bus. Read More >
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