Tag Archive for: AmpConnect 621

100 Things #54: TEDS Microphone Support for Fast Calibration

TEDS microphone support (with appropriate hardware) in SoundCheck makes your audio measurement system setup and calibration fast and simple. Listen’s portable and budget-friendly AudioConnect 2  audio test interface, and the AmpConnect 621 multi-channel, high resolution test interface both support TEDS.

SoundCheck Supports TEDS Microphones for Fast Calibration

Learn more about Listen’s hardware with TEDS Microphone Support

Check out the new features video for Listen’s AudioConnect 2 and AmpConnect 621, which both support TEDS microphones.


Video Script: TEDS Microphones Support in SoundCheck for Fast Calibration

A TEDS, or Transducer Electronic Data Sheet, compatible microphone, is a measurement microphone with a programmed data chip. The data chip stores a wide variety of calibration data including the microphone’s serial number, sensitivity, and date calibrated information. This makes setup and calibration with a TEDS microphone fast and easy, particularly in a multichannel system.

Did you know that SoundCheck includes direct support for TEDs microphones with supported hardware? This capability is available in SoundCheck 18 and later. When this is combined with Listen’s AmpConnect 621 multi-channel, high resolution test interface, setup and calibration could not be easier. Let’s take a look.

Here’s my SoundCheck Calibration Window with 6 separate measurement microphones with 6 signal paths and calibration files. This 6 mic array might be used for in-vehicle audio testing, for example. When a TEDS compatible test interface like Listen’s AmpConnect 621 is detected, the “Read TEDS” button in the Calibration window is available. When depressed, SoundCheck can retrieve the microphone’s serial number, mic sensitivity and calibration date directly from a TEDS mic. The process can be repeated for each connected TEDS mic. Setup could not be easier.

Now we want to hear from you. Do you use TEDS microphones for audio measurements? Let us know in the comments.  For more information, visit ListenInc.com.





100 Things #42: Measuring Max SPL of a Vehicle Infotainment System

SoundCheck is ideal for making in-car measurements such as Max SPL, frequency response and distortion. In fact, SoundCheck is the only full-featured audio test system that offers true nth octave real-time multichannel analysis of 6 microphones simultaneously, that we need for some in-car measurements.  In this short video we demonstrate how we can make Max SPL measurements using a 6 microphone array with SoundCheck and an AmpConnect 621 audio interface. You could make these measurements as part of an end-of-line QC test, in the R&D lab, or to compare various car infotainment systems.

In-Car Max SPL Measurement

Learn More About Automotive Measurements

Watch our Automotive Measurement Seminar in which we make in-car measurements of Max SPL, Frequency response and Buzz, Squeak & Rattle.

Read a short article about the work that the AES Technical Committee on Automotive Audio is doing on Max SPL measurements.

A free pre-written SoundCheck test sequence is available to measure both the Max SPL Spectrum and a single, power averaged value for Max SPL in line with the AES TC-AA working group’s proposed guidelines.

A comprehensive resource on in-car Max SPL measurements is the Audio Engineering Society Technical Committee on Automotive Audio (TC-AA). Their in-vehicle measurements white paper (draft) aims to define repeatable and defined car audio system measurements and in addition to the measurement methods, contains information on standardized test configuration, for example microphone and seat positioning.

Main webpage on SoundCheck for Automotive Measurements.


Video Script: Measuring Max SPL of a Vehicle Infotainment System

Did you know SoundCheck can make in-car measurements such as Max SPL, frequency response and distortion? In fact, SoundCheck is the only full-featured audio test system that offers true nth octave real-time multichannel analysis of 6 microphones simultaneously, that we need for some in-car measurements.  In this short video I’m going to demonstrate how we can make Max SPL measurements using a 6 microphone array with SoundCheck and an AmpConnect 621 audio interface. You could make these measurements as part of an end-of-line QC test, in the R&D lab, or to compare various car infotainment systems.

In this test, we use a 6 microphone array to represent the driver’s head. We mount it on a tripod so that it’s easily adjusted to the position where the head would be.

This is placed in the driver’s seat of the car, with the tripod legs as far back on the seat as they’ll go, right against the backrest. The height and angle of the seat are set to the minimum or lowest position. The AES is working on a proposed standard for this type of measurement that defines some very specific dimensions between the pedal and backrest, the height of the stand, and the inclination of the back rest. For this demo, I’m not going to be that precise, but as you can see, I am making sure that I have recorded the dimensions I am using, and the mic array is in a fairly typical driver head position.

Now let’s measure Max SPL. We’ll use broadband monophonic pink noise and we’re going to crank the volume to the max   – even outside of the car this is going to be loud!

It’s hitting 110 dB and we’re going to play it for 30 seconds and take the linear average or Leq. Here you can see the readings on the six microphones, and the black line representing the spatial power average. The test sequence is calculating the overall Max SPL as 111 dB C weighted, and also displays the Max SPL spectrum from 20Hz to 20 kHz.

If you’d like to learn more about in-car measurements, check out our automotive measurement seminar, in which we also demonstrate frequency response and distortion measurements. You can find this in the audio measurements playlist on our Youtube channel! This test sequence that I just used for measuring Max SPL is also available for download, free of charge, from our website.


AmpConnect 621 Demo Video

In this short video, sales engineer Les Quindipan gives a brief overview and demonstration of the new AmpConnect 621 multichannel, high-resolution audio interface.

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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