product demonstration videos

AudioConnect 2 Audio Measurement Interface Demonstration

What makes an audio measurement interface different from any other audio interface? This is a good question. As you probably know, SoundCheck works with most audio interfaces – this is advantageous as our customers can use hardware they already own, keeping the overall system cost down.

However, if you don’t have an audio interface and need to get one at the same time as your test system, there are many advantages to purchasing dedicated test hardware such as the AudioConnect 2, or for multi-channel applications, the AmpConnect 621. They include many features specifically designed for audio test, such as microphone power and internal switching. This saves money on other components. They are designed for production and field measurements so they are ruggedly constructed, and unnecessary features such as front panel controls are eliminated to avoid accidental adjustment. Perhaps more importantly, Listen’s audio interfaces are configured for full plug’n’play automated setup that hugely simplifies the setup process and virtually eliminates the possibility of incorrect configuration.

Watch this short 5 minute video to learn more.

 AudioConnect 2 Audio Measurement Interface Demonstration Video

Learn more about the AudioConnect 2 Interface

Check out our product information page, and another short video that we made explaining the philosophy around offering our latest generation audio interfaces.

More Information?

Curious? Contact our sales team for more information and pricing.

Directional Audio Measurements with the MDT-4000 Turntable

Have you ever wondered about the thought process that goes into designing a new audio test product? Our sales and support teams worked closely with Portland Tool & Die during the design of the MDT-4000 turntable for directional audio measurements to ensure it addressed all the pain-points that our customers had with other brands – speed, accuracy, portability, control and more. In this short video, designer Kris Hett demonstrates these features and you can see how seamless integration is with SoundCheck.

 Directional Audio Measurements with the MDT-4000 Turntable

Learn more about the MDT-4000 Turntable

Check out our product information page, and our comparison of the MDT-4000 specifications with other popular turntables

Free polar plot test sequence for use with the MDT-4000 Turntable. This gets you up and running quickly with polar plots, and can be used as a base for creating your own measurement sequences.

More Information?

Curious? Contact our sales team for more information and pricing.

100 Things #86: Listen’s Latest Generation Audio Interfaces

Traditional sound cards have drawbacks for audio testing, such as physical controls that can easily be altered, cabling errors, and the need for manual calibration. Two interfaces in our next generation of audio testing hardware: AudioConnect 2, and AmpConnect 621, fix these common problems. Both interfaces feature high resolution audio inputs and outputs, TEDS compatibility, microphone power, and internal signal routing. AmpConnect 621 features a built in amplifier and impedance measurement. AudioConnect 2 is portable and can be fully powered over USB type C.

Listen’s Latest Generation Audio Interfaces

Learn more about Listen audio interfaces

Read on for more information and technical specifications of the AmpConnect 621, AudioConnect 2. Audio interfaces can be used with a variety of test hardware including Bluetooth interfaces, turntables, accelerometers, and more. Check out all of SoundCheck’s compatibility with audio testing hardware.

Video Script:

Since SoundCheck was launched in 1995, it has become a standard as an affordable and flexible audio test and measurement system using pro audio soundcards as an audio interface .  But did you know that we also offer our own audio interfaces?

You may wonder why, since soundcards offer so many advantages, so let me share some secrets about why we designed our own hardware, and some of its lesser-known benefits.

When correctly calibrated, high-end soundcards are accurate and cost-effective, especially for high channel counts. But they do have some drawbacks, particularly when used on the production line. Common pain points with sound cards include:

  • Cabling errors – it’s easy to connect something up wrong, or to have a faulty or loose cable 
  • People may accidentally adjust the controls on the soundcard, especially in a busy lab or factory environment – if someone fiddles with your gain control mid way through a production run, you’re going to have a problem!
  • It’s not a big deal when you only have one soundcard to set up, but if you are configuring 30 or 40 production lines, it takes time to configure the channels and calibrate everything. And on top of that, your test integrity depends on this being done correctly.

Our latest generation hardware combines high resolution audio inputs and outputs with TEDS compatibility, microphone power, internal signal routing, and in some cases amplifiers and impedance measurement, to simplify your setup.

These are our two latest audio interfaces, AudioConnect 2 and AmpConnect 621. AudioConnect 2 is our ultra-portable, laptop-powered, low cost 2-channel interface. It has 2 input and 2 output channels and a headphone output. The inputs offer both constant voltage power for our SCMs, and constant current for IEPE microphones and all inputs support TEDS. It’s great for headphone measurements, or for a portable setup. AmpConnect 621 has six powered microphone inputs and two output channels, as well as a built in amplifier and impedance current sensor. This one’s great for multi-channel applications such as measurements with a 6-mic array, or when you need to drive a passive speaker or artificial mouth.

So first off, you can see that these are more than just a soundcard – we’ve put all the functionality you need in one box, with all the signals routed internally, This means that the only connection you have is one USB cable and that makes it hard to mess up your connections. So we can take a speaker testing setup that looks like this and replace it with this. And it actually costs less than all the separate components.

You’ll also notice something missing – buttons. There are no knobs or buttons on the front panel, although we do have level and overload indicators so you can be sure that everything is operating within maximum dynamic range. All control is via the software. This means that once you set your hardware configuration as part of your test sequence, no-one can deviate from that at all – either by adjusting knobs, or by incorrectly setting it up in the first place. This ensures that your test is being run correctly, and it’s particularly useful if you are relying on 3rd party manufacturers to run your tests. If you specify the hardware, software and test sequence, you can guarantee your product is tested to your exact standards with no room for error.

Another benefit of Listen hardware is fast setup with seamless plug and play operation. The calibration data is stored on the device’s firmware so when you connect your interface to SoundCheck, the system reads the calibration values automatically so there’s no need for manual calibration. The input channels also automatically populate with sampling rates, and the device self-test requires no additional cabling as all switching is internal. If you’re using TEDS microphones, you can also automatically read this data too.

So, as you can see, although we always have and always will support a wide range of soundcards, our own hardware offers some clearly defined benefits. Conversely, there are other situations, for example high channel count, where a sound card is the more cost-effective option. Our goal is test system modularity and flexibility, so sound card or audio interface – the choice is yours.

New Transient Distortion Measurement Algorithm

At Listen, we’re at the forefront of audio measurement research, and we’re always looking to improve on existing audio measurement techniques, even our own! Loose Particle detection has been a valuable production metric for analyzing transient distortion since we launched it in 2004. This new iteration uses our own original research to improve accuracy and reliability, show a clear correlation to audibility, and simplify limit setting. In addition to production line testing of speakers, headphones, drivers and other devices, it is also valuable for automotive Buzz, Squeak and rattle (BSR) measurements and measuring rattling components such as keys and buttons on a variety of devices. All is explained in the short video below.

Transient Distortion Detection Launch Video

Watch our launch video (broadcast date 05/25/2023) for the full details.

 

Ready to Measure your Transient Distortion?

If you have SoundCheck 21, you already have this new algorithm! Download our free complete end of line test sequence with enhanced Loose Particles to start using it right away.

If you don’t have SoundCheck 21, but have an older version, you can send us your recorded waveforms and we’ll analyze them for you and send you the results. Please contact sales@listeninc.com for a test sequence to record the waveforms.

No SoundCheck system at all? No problem! You can send us your speakers and we’ll test them for you. Or we may be able to arrange a system loan. Contact your sales engineer at sales@listeninc.com for more information.

Prefer to Read About It?

We know not everyone has 15 mins free to watch a video, although its hard to beat the benefits of a proper demonstration. So here’s a brief summary of the information about this new algorithm that is presented in the video:

What it does

The new algorithm measures transient distortion caused by loose particles that may become trapped in a device during manufacture and create an unpleasant sound when they vibrate in the finished product. This is measured in the time domain rather than the frequency domain as these artifacts appear randomly over time, and not periodically in the same way that harmonic distortion artifacts are presented. This algorithm has a couple of unique features:

1) It measures transient distortion separately from harmonic distortion which gives deeper insight into the failure mode and accelerates troubleshooting, particularly on the production line.

2) It’s easy to correlate with audibility as the algorithm removes the stimulus waveform to allow the user to listen to just the distortion artifacts. As well as enabling the user to truly understand how measured results correlate to listening, this also facilitates limit setting.

3) It’s reliable even in the presence of transient background noise since it relies on a cumulative event count rather than a single event triggering a fail. Limit setting is simple as it is not frequency dependent

 

Applications

  • Production line driver test
  • Production line finished product test (rattling buttons, keys, grills, and other components)
  • Buzz, Squeak and Rattle (BSR) / Impulsive distortion measurements in cars

 

How it works

Like Listen’s original 2004 transient distortion detection algorithm, enhanced Loose Particles relies on a time domain analysis of the waveform. However, rather than simply filtering and counting transients, it removed the stimulus, performs a time domain analysis of the remaining transients, then applies a unique Prominence calculation to evaluate each transient in the context of the surrounding waveform. A threshold is applied, and the number of transient events above that threshold are counted. The event count indicates whether a device has a transient distortion problem. Transient events caused by speaker manufacturing issues tend to repeat many times as particles bounce around in side the speaker, or components vibrate. In contrast, background noise events occur infrequently during the duration of the measurement. The threshold is set based on audibility, and the Loose Particle count limit can be set according to the environment to fine-tune the algorithm for the specific operating conditions.

 

Graphic demonstrating how the Transient Distortion algorithm (Loose Particles) works

4 Stages of the enhanced Loose Particles algorithm for transient distortion measurement: Response waveform, Loose Particle waveform, Prominence and enhanced Loose Particles.

 

 

For additional background, comparison to other methods, such as Crest Factor Analysis, and live demonstrations, please check out the video above.

 

Learn More

SoundCheck 19 New Features Video

In this short video, sales engineer Les Quindipan gives a brief overview and demonstration of the new features and functionality of SoundCheck 19, including the multichannel RTA, RT60 Room Acoustics module, AmpConnect 621 control, and more.