Testing Automotive Audio with A2B

How to Test Automotive MEMS Microphones Over A2B | SoundCheck How do you measure automotive microphone arrays connected through an A2B bus? This section of the seminar demonstrates how SoundCheck can communicate with an A2B audio interface to capture signals from automotive MEMS microphones and perform measurements using the same analysis tools available for conventional audio inputs. A2B (Automotive Audio Bus) is particularly useful for automotive microphone testing, where the vehicle's internal microphones may be used for voice recognition, communications, active noise cancellation, and road noise cancellation. Instead of capturing the signal with external measurement microphones, SoundCheck can acquire the microphone signals directly through the vehicle's digital audio network. In this video you’ll learn: What A2B is and how it is used in automotive audio systems Why A2B is useful for testing automotive microphone arrays How A2B transports audio, control data, clock, and power How multiple microphone devices can be daisy-chained How to configure an A2B audio interface for MEMS microphone testing How to connect A2B channels to SoundCheck input signal paths How to measure multiple MEMS microphones simultaneously How captured A2B signals can be analyzed and tested in SoundCheck A2B is a high-bandwidth, bi-directional digital audio bus that can transport audio data, control information, clock, and power over a single two-wire unshielded twisted-pair cable. Multiple devices can be connected in a daisy chain, while the bus can also supply power to devices in the chain. This can reduce wiring complexity and weight compared with conventional automotive connections. The demonstration uses an Analog Devices A2B sound card and AD2425 evaluation board connected to multiple boards containing PDM MEMS microphones. The example setup provides four MEMS microphone inputs, two line inputs, and two line outputs. A separate Listen AudioConnect and SC Amp are used to drive a speaker with pink noise for testing the microphones. The A2B hardware is configured using Analog Devices SigmaStudio to match the physical system. Once configured, SoundCheck recognizes the A2B interface through its ASIO channels. The microphone inputs can then be assigned to individual SoundCheck signal paths and calibrated alongside the rest of the measurement system. The demonstration shows how four discrete MEMS microphone channels can be acquired simultaneously and displayed in SoundCheck using an RTA. The measured microphone responses can be stored in memory, analyzed, and compared against limits just like signals from other audio measurement sources. Once the microphone data has been captured through A2B, SoundCheck can apply its standard measurement and analysis capabilities to the signals. This allows the same platform to be used for automotive microphone validation and more specialized applications, such as evaluating microphones intended for active noise cancellation or road noise cancellation. This section is intended for automotive audio engineers, acoustic engineers, microphone engineers, MEMS microphone developers, and test engineers working with digital automotive audio systems and microphone arrays. Related topics include A2B testing, automotive microphone testing, MEMS microphone testing, PDM microphones, automotive microphone arrays, active noise cancellation, road noise cancellation, digital audio buses, and SoundCheck automotive testing. Segment taken from our full Automotive Audio Testing Seminar, available here: https://www.listeninc.com/automotive-...