07. December 2018

Smart Measurements for Smart Devices

Smart Measurements for Smart Devices

Smart devices is a booming market and the number of devices available is growing rapidly. The market is wide open, and competition is fierce. As a manufacturer of smart devices, one way to stay ahead of the game is to run tests to ensure the quality of the acoustic responses of the microphones and speakers in one’s devices. A quality testing procedure is also, certainly, something that is needed for repair and refurbishment of such devices.

Devices such as smart speakers, mobile devices, personal assistants, smart thermostats, smart security cameras and similar have entered the consumer market with force during the last couple of years. More and more household appliances are getting connected to the smart home network. Most of those devices have an audio interface, such as built-in loudspeakers or microphones to interact with the user. Some of them even deliver an impressive level of audio quality. How easy is it to test this quality?

The Challenge
When testing loudspeakers and microphones as separated components, the stimulus signal and the measured signal going to and coming from the component are directly connected from the loudspeaker or the microphone to the Audio Analyzer system. This is called a “Closed Loop” test setup. However, in smart devices, where the device has been completely assembled, there are usually no designated interfaces allowing access to the back of the components. Injecting a test signal into the loudspeaker under test, or measuring a test signal acquired by the device’s microphone cannot be achieved in a closed loop.

FX100 Loudspeaker Test
FX100 Loudspeaker Test

The Solution
The solution is to use an “Open loop” test setup. For the loudspeaker test, the test signal is not injected by the analyzer, but rather produced by the device under test (DUT) itself. For the microphone test, the results are not immediately received by the analyzer, but rather first recorded by the DUT itself. This open loop solution is possible by using the NTi Audio “External GlideSweep” measurement technique. This allows the FX100 Audio Analyzer to synchronize to a played-back signal.

Open Loop System
Open Loop System

Take a look at this video to see how easily such smart device measurements can be performed on the example of an Amazon Echo Dot.

Read more about how to test smart devices.

Here you will find more about the Flexus FX100 Audio Analyzer.

Press Picture(s) for download here.

Categories: Quality Control

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