April 2023

Interview With Tomasz Zernicki Of Zylia
Boston Audio Society meeting features immersive audio / volumetric recording.
Article by Alvin Foster

  Anna Czerwoniec, marketing & sales director at Zylia, introduced Tomasz Zernicki, Zylia CEO and co-founder. (Both have PhDs, not often the case in audio.) Zylia is a new, innovative company supplying tools for video-audio production. Zernicki's doctorate is in electronics, digital audio processing, and telecommunications. His specialization is VR (virtual reality) production and volumetric audio recording. He has made significant contributions in audio compression standards such as MPEG, mph 3D, 360-degree audio, and music production. Zernicki was awarded as an outstanding young scientist by the Polish National Center for Research and Development, and was also selected as an outstanding innovator by 'New Europe 100: Eastern Europe's emerging technology stars' (selected by Res Publica, Google, Visegrad Fund, and the Financial Times.

Tomasz Zernicki, Piotr Szczechowiak:Founders of Zylia, which has developed a technology that uses just a single microphone to record multitrack sounds that can later be separated.

Zernicki followed his introduction by saying that among Zylia's goals is teleporting to any place in the world or the metaverse to participate virtually in live events with Zylia products. He introduced Florian Grond, also with a doctorate, as their Creative Sound Engineer; Grond was involved in many Ambisonic recordings and volumetric audio.

Zernicki said that the goal at Zylia is to shorten the distance between the audience and artists by supplying immersive audio solutions. "We believe that 3D audio is a key part to re-create the emotions that go together with the video or any media content." Fortunately, interest in live concerts even after Covid continues to grow. There has been an explosion of available game platforms, VR headsets, and devices that supplement participation in virtual realities. Now MPEG, the same group that developed MP3, is working on volumetric audio rendering standards, which will eventually be built into smartphones, receivers, and broadcast media.

Zylia was created specifically to support the production of six degrees of freedom (DoF) and volumetric 3D audio experiences. The Zylia 6DoF VR/AR set allows audio engineers and creatives to place multiple customized Zylia ZM-1S microphones around a sound scene to capture audio that supports truly immersive experiences with freedom of movement through the 3D space. With Zylia microphones and equipment, in other words, you can decide where you want to be at the concert. You can position yourself (virtually) next to the conductor or drummer, or occupy the best seat in the hall. Volumetric audio works by enabling listeners to decide the position they would like to listen in.

Tomasz supplied several VR samples. One employed 30 musical instruments and players. Using our own headphones at home for the Zoom presentation, we were able to navigate around the artists. The playback was highly compromised because not each person listening to the presentation had the VR glasses or the headphones used by Zylia. Within these limitations, while watching the video on our screen, some feeling of 'you are there', or live, was present. Some of the six degrees of freedom was clear even in the extremely compromised playback environment.

The two models of Zylia ZM-1 and ZM-1S microphones organize the MEMS mike capsules on a sphere. (MEMS mikes are largely based on electret capsules and the Zylia mike has onboard preamps and A/D converters. MEMS mikes are also known as mike chips or silicon mikes.)

The soccer-ball-size sphere has 19 capsules to enable 360-degree recordings. With multiple ZM-1S microphone arrays (time code input allowing for synchronization) you can record a volumetric audio experience by probing the space with Ambisonics spheres. The Zylia corporation sells a recorder and the software solutions to create your own VR. The result is a high-quality 3rd order Ambisonics recording in which you can walk around and get involved. Each of the omni-directional digital MEMS capsules contains an ADC and the 19 outputs are multiplexed to USB, with the option of utilizing timecode inputs for synchronization. The factory-calibrated capsules are 48kHz / 24-bits. (No XLR cables are used because of their bulk.) Tomasz displayed a frequency response graph on the screen showing a +/-4dB from 20 Hz to 20 kHz, and claimed a sensitivity variation among the 19 microphones of 0.1dB. The MEMS mike capsules do not change their characteristics over time, a requirement for Ambisonics. (Typical electric or condenser microphones must be recalibrated periodically.)

Zylia has dedicated software that allows beamforming, X-Y, B-format, Dolby Atmos, 3D sound, Blumlein, and other standard output arrangements from the 19 capsules. Zylia supplies a 19-channel input recorder to capture the output for your DAW. Currently it is the only 19-channel, USB recorder on the market Having more than four capsules is a requirement for Higher-Order Ambisonics (HOA), a technique for reproducing a soundfield at a particular point to an arbitrary degree of spatial accuracy. Added mikes are needed to differentiate the position of the musicians more accurately in Ambisonics, binaural, and multichannel recordings.

That is, the deployment of more capsules, when done properly, can sometimes yield a more accurate placement of instruments within the ensemble soundfield. Tomasz outlined in another audio-video sample the beam pattern options possible, and how a beam can be aimed anywhere among the musicians to extract the audio. He also sonically demonstrated binaural, audio, stereo, and mono sound from a third-order Ambisonics recording made with the Zylia ZM-1 microphone.

To show volumetric audio, using another video sample, Tomasz placed about 10 Ambisonic mikes around a car and one mike inside. With the Zylia software you can easily create Ambisonics, volumetric audio when walking around the car. Sonically, you can simply figure out where the person is standing near the car both by the engine's loudness and HOA directional clues. This is true even in places where the microphones are missing inside and outside the car.

In another video, Tomasz used 30 microphones totaling 600 audio channels. Each mike was placed in and around a small onstage orchestra. A total of 600 audio channels were captured and fed to a single computer. With Zylia's Ambisonic VR software, the location of each musician and how close you are standing next to the violins or horns in the video-audio sample could be figured out. (Nick and I heard a demo at the show with VR glasses. It was excellent, the best VR we have experienced.) More samples can be found on their site, Zylia.co, or on YouTube.

Questions & Answers
Alvin Foster noted that the microphone graph displays a significant rolloff in the bass below 50 Hz. Florian Grond replied that if necessary, the engineer can add a small bass boost. Foster asked about the overall s/n of the Zylia system given that the specification for each mike is only 69dB. Tomasz replied that the dynamic range was 105dB. (After the meeting, David Hadaway supplied his explanation for Zylia's spec: Their mike has a 69dB s/n referenced to 94dBspl. So the noisefloor is 25dB. Mediocre but typical for small mikes such as lavalier types. Since they are being used in the near field, that shouldn't be a problem. The max level is 130dB, so the dynamic range is 130 - 25 = 105dB.)

Brad Meyer asked about costs. At B&H the 19-channel recorder costs $1360 and the Zylia mike with software $1375.

Alvin Foster asked if the mike and software came with a trial period. No trial for the hardware, but a trial for software does exist. And some retailers may offer a trial period.

According to Tomasz, the market for Ambisonics is large and growing. Dolby Atmos is in lots of theaters, Hollywood is starting to incorporate HOA, and the game industry has taken VR and volumetric audio to another level of immersion. Volumetric audio hand in hand with video increases immersion and the 3D experience. The gaming industry already has a bigger budget than Hollywood movies.

The ZOOM meeting went on for over 2:45, longer than our norm. Tomasz Zernicki and Florian Grond supplied many anecdotal examples and experiences of virtual reality that can be captured with VR when combined with volumetric audio. Most of the participants suggested that better days for the expanding base lie ahead.

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Specifications
Zylia ZM-1S Ambisonics Microphone Array
High-quality 360 audio recording -- third-order Ambisonics
19 microphone omni-directional digital MEMS capsules distributed on a sphere
Timecode input channels
Multiple ZM-1S timecode synchronization
LED ring status indicator informing about recording status
48 kHz / 24 bit recording
USB connectivity makes the process of recording easy
Recording: Zylia Studio PRO plug-in, Zylia 6DoF VR/AR software, or any DAW

Zylia ZM-1S Multi-Channel Recording Unit
Recording timecode input allows for the synchronization of multiple ZM-1S microphones as well as other devices connected to the recording systems such as video cameras.

Can be controlled by an external timecode signal
Audio line input
Full-Scale voltage input (single-ended): 2.1 VRMS
ADC sampling rate: 48 kHz
ADC bit resolution: 24-bit
Timecode support: 
SMPTE Timecode Rates: 23.98, 24, 25, 29.97, 29.97DF and 30 FPS

Company Information
Zylia Sp. z o. o.
Mostowa 27,
61-854 Poznan, Poland

Voice: 0048 61 279 40 44
Website: Zylia.co