100 Things #69: Testing MEMS Microphones In SoundCheck

Testing MEMS microphones and devices in SoundCheck is as simple as any microphone test. In fact, SoundCheck’s ability to work with different devices means MEMS setup is plug and play. Just like testing an analog microphone, SoundCheck can perform standard tests using microphone substitution or microphone subtraction. SoundCheck allows up to 64 channels of simultaneous acquisition, so daisy-chaining MEMS inputs easily expands the number of hardware inputs. Testing MEMS with SoundCheck is simple for both individual components and finished products.

Testing MEMS Microphones In SoundCheck

Try MEMS microphone measurements for yourself!

Our free test sequence includes not just one, but three pre-written test sequences for testing MEMS microphones including Frequency and Sensitivity, Microphone Substitution, and Power Supply Rejection.

Video Script:

As you know, SoundCheck offers unrivaled flexibility for testing different types of devices, and testing a MEMS microphone is as simple as adding a small, stand-alone MEMS interface to your test setup.

Let’s look at how we measure a digital MEMS- or micro-electromechanical- microphone in SoundCheck from component level to a finished product.

Testing digital MEMS microphones is identical to testing an analog microphone, we simply add a MEMS interface like the DCC-1448 to convert the digital PDM signal to PCM. This interface has 2 inputs, and  two interfaces can be daisy chained together for 4 discreet MEMS inputs. Performing the measurement is the same as with an analog mic. SoundCheck calibrates the source speaker by first measuring the speaker’s response and applying the reciprocal response to the speaker, effectively flattening the speaker. This removes the speaker’s influence on the MEMS microphone measurement [diagram.. Short video B-roll]. Alternatively, we can capture the response simultaneously though the MEMS mic and a calibrated reference mic, and subtract the reference mic’s response from the MEMS response, leaving the raw response of the MEMS microphone [diagram].

SoundCheck also tests MEMS sub-assemblies like a hands free microphone array. These sub-assemblies usually have multiple MEMS microphones and onboard D/A. Since SoundCheck easily supports multiple channels and multichannel audio hardware like our own AmpConnect 621, scaling for testing 4 or 6 channel MEMS sub-assemblies is a snap.

Of course, once the MEMS sub-assembly is installed into the finished product, we can measure that too. Here’s a test setup of SoundCheck testing the hands free MEMS microphones installed in a vehicle. SoundCheck plays a test stimulus through the mouth simulator and captures the response through the on-board microphones. The microphone response is transferred to SoundCheck via a BTC-4149 Bluetooth interface paired to the vehicle’s head unit, then analyzed. 

Aside from basic audio quality tests using sine waves, SoundCheck can also measure MEMS microphones with real world signals like pink noise, speech, music and more for all types of tests including communications, voice activation and more.

Check out our website for more information and free test sequences for measuring MEMS microphone sensitivity, frequency response and power supply rejection.

100 Things #10: Low Cost Audio Measurement with SoundCheck ONE

SoundCheck’s low cost audio measurement software, SoundCheck One, is a budget-friendly solution for basic audio tests. It is simple to use with sequence templates to quickly test simple devices such as headphone, microphones and speakers. Using the same advanced algorithms as the regular version of SoundCheck, it is fully compatible with the regular version, and may be upgraded at any time.

Low Cost Audio Measurement with SoundCheck ONE

Learn more about SoundCheck ONE

SoundCheck Packages and Modules

 

Video Script: Low Cost Audio Measurement with SoundCheck ONE

SoundCheck One is an entry level SoundCheck package designed for basic transducer measurements. It is low-cost and easy to use, making it ideal for production, end-of-line testing and benchmarking applications.

Under the hood it features the same unique algorithms and advanced test methods as the full version of SoundCheck; the difference is in the user-interface.

SoundCheck ONE is supplied as a complete package including software and an audio interface – either an AmpConnect ISC or AudioConnect. Instead of SoundCheck’s sequence editor for test development, pre-configured test templates for speakers, headphones and microphones are provided.

Each template contains all the typical measurements for those devices. The tests themselves cannot be edited but individual steps can. For example frequency range, levels and limits can be modified and measurements toggled on or off to generate product-specific sequences. This makes it fast and easy to configure basic tests that can be deployed across multiple products.

Because SoundCheck ONE uses the same data format as full-featured versions, its curves, waveforms and results can be shared for deeper analysis with users who might have an advanced license.

At approximately half the price of a regular SoundCheck system, SoundCheck ONE is a great entry-level option. While it doesn’t offer the limitless flexibility of the full versions of SoundCheck, its template-based approach makes it extremely simple to configure and use.

Furthermore, because the SoundCheck platform is modular, your investment is not wasted if future testing demands more flexibility. SoundCheck ONE can be upgraded to a more advanced SoundCheck package with full sequence development capabilities at any time. The test sequences will continue to work on the upgraded system, where they can be expanded and developed to meet all your measurement challenges.

 

 

 

 

Advanced Microphone Measurements Part 2

Listen’s Support Manager, Steve Tatarunis, discusses some of the more advanced aspects of microphone measurements. This is an expansion of material covered in the Basic Microphone Testing webinar, and part two of the full advanced microphone measurements seminar. Advanced Microphone Test part 1 shows microphone measurements like polar plotting, open loop, active/passive noise rejection, and more. This seminar is of interest to anyone testing microphone characteristics, both in an R&D and production line environment. The tests featured in this seminar can be used both at component level, whether selecting microphones for devices or component QC, or these tests can be performed on finished products like smartphones, smart speakers, and more.

Seminar topics include:

More advanced aspects of microphone testing including:

  • Phase
  • Open loop microphone testing for voice activated devices such as smart speakers, automotive audio, etc.
  • Intermodulation distortion
  • Advanced hardware and test configurations for measuring microphone arrays
  • Beamforming with broadside and endfire arrays
  • Measuring MEMS devices frequency, sensitivity and power supply rejection (PSR) performance

Presenters: Steve Tatarunis
Duration: 40 Mins

Advanced microphone measurements resources

SoundCheck comes with many pre-written sequences including the sequences demonstrated in this seminar including the microphone test sequences for measuring microphone self noise, microphone substitution, frequency response and sensitivity, and open loop. Additionally, we offer the sequences featured in this seminar measuring digital MEMS microphones and microphone intermodulation distortion in our sequence library for download. Along with the sequences featured in this seminar, our sequence library is full of additional pre-written sequences for basic microphone measurement.

More about advanced microphone measurements

Check out our main page on Microphones, which includes links to test sequences, relevant products and more.

Advanced Microphone Test Part 1

Listen’s Support Manager, Steve Tatarunis, discusses some of the more advanced aspects of microphone test. This is an expansion of material covered in the Basic Microphone Testing webinar. This seminar is of interest to anyone testing microphone characteristics, both in an R&D and production line environment. This is part one of two in our advanced microphone measurement seminar series, with part two also available on our website. The tests featured in this seminar can be used both at component level, whether selecting microphones for devices or component QC, or these tests can be performed on finished products like smartphones, smart speakers, and more.

Seminar topics include:

  • Demo of microphone test methods substitution, equalized source, and transfer function in SoundCheck
    • How to calibrate for these measurements
    • What are the trade-offs?
  • Advanced microphone test measurements
    • Polar plot
    • Self noise and signal to noise
    • Open loop
    • Active/passive noise rejection

Presenters: Steve Tatarunis
Duration: 63 Mins

Advanced microphone test resources

SoundCheck comes with many pre-written sequences including the sequences demonstrated in this seminar including the microphone test sequences for measuring microphone self noise, microphone substitution, frequency response and sensitivity, and open loop. Additionally, we offer the sequences featured in this seminar microphone polar plot measurements with the new MDT-4000 turntable and open loop microphone test in our sequence library for download. Along with the sequences featured in this seminar, our sequence library is full of additional pre-written sequences for basic microphone measurement.

More about advanced microphone tests

Check out our main page on Microphones, which includes links to test sequences, relevant products and more.

Basic Microphone Measurement Seminar

Technical Support Manager, Steve Tatarunis discusses and demonstrates basic microphone measurement, and how to measure characteristics that matter. Three different basic microphone test methods are explained including substitution, equalized source, and two-channel transfer function. Testing microphones in SoundCheck yields a full array of important results, since SoundCheck can be used to test microphone specifications including frequency response, sensitivity, impedance, directivity/polar pattern, polarity, dynamic range, signal to noise/self-noise, polarization/bias. Finally, two basic microphone measurement techniques are demonstrated: equalized source, and microphone substitution.

 

Seminar topics include:

  • Common microphone types and how they work
  • Microphone specifications
  • How to measure microphones using the two standard methods available in SoundCheck
    • Substitution method
    • Equalized speaker method
  • R&D and production test environments
  • Important measurements such as frequency response, sensitivity, etc.

Presenters: Steve Tatarunis
Duration: 34 Mins

Basic microphone measurement resources

Our sequence library is full of pre-written sequences for basic microphone measurement. Additionally, SoundCheck comes with many pre-written sequences including the sequences demonstrated in this seminar. To take these sequences to the next level, we offer more complex testing scenarios like microphone polar plot measurements with the new MDT-4000 turntable.

More about basic microphone measurement

Check out our main page on Microphones, which includes links to test sequences, relevant products and more.