Tag Archive for: 621

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 AmpConnect 621 Multichannel, Multifunction Audio Interface

AmpConnect 621

The new AmpConnect 621 is Listen’s next generation multichannel, multifunction, high resolution audio test interface. It is ideal for any application where more than 2 channels are needed, for example, automotive audio, voice-activated device measurements, sound power measurements and measuring devices with multiple speakers such as soundbars and smartphones. With a sample rate of up to 192kHz, it is also a great choice for measuring high resolution devices such as headphones and hearables. Additionally, it includes all the functionality required for audio testing in just one unit, including an amplifier, microphone power supply, line outputs and digital I/O.

AmpConnect 621 features 6 inputs, 2 line outputs and one amplifier output. All inputs offer microphone power (SCM, IEPE and pre-polarized), to accommodate many types of couplers, accelerometers and reference microphones – even the new Brüel and Kjær 5128 high resolution head and torso simulator. Full TEDS support for microphones and accelerometers simplifies setup and calibration by importing the data at the click of a button. The 2 line level outputs plus  a separate 50W amplifier route the output signal to any sources, powered or needing amplification, (e.g. artificial mouth, speakers, headphones, automotive head units). Impedance measurements using the amplifier output, along with output voltage monitoring, are performed entirely internally and do not require using any of the 6 external input channels, leaving them open for other measurements. This, along with digital I/O, simplifies operation as signals are all routed internally with no additional cabling required. The device connects to the computer with a single USB cable; the only additional cables required are those connecting your microphones and DUTs. This all-in-one approach offers excellent ground loop immunity in comparison to discrete components.

The interface has no control knobs on the front; control is entirely through the SoundCheck software interface. This minimizes errors by making it impossible for settings to be accidentally changed. For example, in a production environment, the only way the operator can adjust the settings is by modifying the test sequence, and access to this can be restricted via operator access rights. This helps OEMs ensure test integrity when requiring contract manufacturers or offshore manufacturing facilities to run their test sequences. This is also advantageous for protecting against accidental changes in a laboratory, particularly when multiple people are accessing the same piece of equipment. The front panel features visual indicators for power, input and output level, amplifier channel and level so that overloads, etc. can be clearly identified.

Test deployment is fast with full plug and play functionality. Channel configuration is fully automatic when the AmpConnect 621 is connected to the SoundCheck computer – the user just needs to adjust driver selection and sampling rate if different from the default values. Calibration data is read from TEDS microphones in SoundCheck’s calibration editor, or easily imported from a calibration file. When setting up multiple systems, the AmpConnect only needs to be configured once, and the setup can be duplicated to other test stations; there is no need to re-configure AmpConnect 621 each time.

AmpConnect 621 offers the option to use WASAPI-exclusive mode with Windows 10 audio devices in addition to the more commonly used ASIO drivers. This advanced communication protocol allows SoundCheck to bypass the Windows audio mixer, sending audio streams directly to the device. This results in lower latency and ensures that there is no sample rate conversion behind the scenes. It also enables SoundCheck to put an exclusive lock on the audio interface so that a measurement cannot be disrupted by system sounds which is valuable in highly automated settings. Multiple WASAPI devices can be used simultaneously, and WASAPI and ASIO devices can be combined to increase channel availability.

Like Listen’s other hardware products, AmpConnect 621 is built to last in production environments. The 17” wide x 2-Units (3.5”) high x 11.5” deep rack-mountable unit is rugged with a new fingerprint-resistant matte finish.


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The New AmpConnect 621 MultiChannel High Resolution Audio Interface

In this short video, Les Quindipan introduces the new AmpConnect 621 multichannel high resolution audio interface, explaining all its features and demonstrating how quick and easy it is to configure. AmpConnect 621 is a high resolution multichannel audio interface with 6 inputs, 2 line outputs, 1 amplifier output (plus everything else you need for audio testing!)

The New AmpConnect 621

Read on to learn more

For more details and technical specifications, check out the AmpConnect 621 product page.

AmpConnect 621 simplifies your multichannel audio test with 6 inputs, 2 line outputs and one amplifier output, along with microphone power, full TEDS support, impedance measurement and digital I/O in a single USB-connected unit. With sample rates up to 192kHz, it is ideal for the measurement of high resolution audio devices. AmpConnect 621 features 6 channels of audio test in a single unit, high accuracy impedance measurement independent of input channels, plug-and-play setup with error-free operation, front panel visual level indicators, and ground loop immunity, all in a rugged and rack-mountable for demanding production environments.