By Mel Lambert
The AES Convention returned to Berlin after a three-year absence, and once again demonstrated that the Audio Engineering Society can organize a series of well-attended paper programs, seminars and workshops, in addition to an exhibition of familiar brands, for the European tech-savvy post community. Held at the Maritim Hotel in the creative heart of Berlin in late May, the 142nd AES Convention was co-chaired by Sascha Spors from University of Rostock in Germany and Nadja Wallaszkovits from the Austrian Academy of Sciences. According to AES executive director Bob Moses, attendance was 1,800 — a figure at least 10% higher than last year’s gathering in Paris — with post professional from several overseas countries, including China and Australia.
During the opening ceremonies, current AES president Alex Case stated that, “AES conventions represent an ideal interactive meeting place,” whereas “social media lacks the one-on-one contact that enhances our communications bandwidth with colleagues and co-workers.” Keynote speaker Dr. Alex Arteaga, whose research integrates aesthetic and philosophical practices, addressed the thorny subject of “Auditory Architecture: Bringing Phenomenology, Aesthtic Practices and Engineering Together,” arguing that when considering the differences between audio soundscapes, “our experience depends upon the listening environment.” His underlying message was that a full appreciation of the various ways in which we hear immersive sounds requires a deeper understanding of how listeners interact with that space.
As part of his Richard C. Heyser Memorial Lecture, Prof. Dr. Jorg Sennheiser outlined “A Historic Journey in Audio-Reality: From Mono to AMBEO,” during which he reviewed the basis of audio perception and the interdependence of hearing with other senses. “Our enjoyment and appreciation of audio quality is reflected in the continuous development from single- to multi-channel reproduction systems that are benchmarked against sonic reality,” he offered. “Augmented and virtual reality call for immersive audio, with multiple stakeholders working together to design the future of audio.”
Post-Focused Technical Papers
There were several interesting technical papers that covered the changing requirements of the post community, particularly in the field of immersive playback formats for TV and cinema. With the new ATSC 3.0 digital television format scheduled to come online soon, including object-based immersive sound, there is increasing interest in techniques for capturing surround material and then delivering the same to consumer audiences.
In a paper titled “The Median-Plane Summing Localization in Ambisonics Reproduction,” Bosun Xie from the South China University of Technology in Guangzhou explained that, while one aim of Ambisonics playback is to recreate the perception of a virtual source in arbitrary directions, practical techniques are unable to recreate correct high-frequency spectra in binaural pressures that are referred to as front-back and vertical localization cues. Current research shows that changes of interaural time difference/ITD that result from head-turning for Ambisonics playback match with those of a real source, and hence provide dynamic cue for vertical localization, especially in the median plane. In addition, the LF virtual source direction can be approximately evaluated by using a set of panning laws.
“Exploring the Perceptual Sweet Area in Ambisonics,” presented by Matthias Frank from University of Music in Graz, Austria, described how the sweet-spot area does not match the large area needed in the real world. A method was described to experimentally determine the perceptual sweet spot, which is not limited to assessing the localization of both dry and reverberant sound using different Ambisonic encoding orders.
Another paper, “Perceptual Evaluation of Synthetic Early Binaural Room Impulse Responses Based on a Parametric Model,” presented by Philipp Stade from the Technical University of Berlin, described how an acoustical environment can be modeled using sound-field analysis plus spherical head-related impulse response/HRIRs — and the results compared with measured counterparts. Apparently, the selected listening experiment showed comparable performance and, in the main, was independent from room and test signals. (Perhaps surprisingly, the synthesis of direct sound and diffuse reverberation yielded almost the same results as for the parametric model.)
“Influence of Head Tracking on the Externalization of Auditory Events at Divergence between Synthesized and Listening Room Using a Binaural Headphone System,” presented by Stephan Werner from the Technical University of Ilmenau, Germany, reported on a study using a binaural headphone system that considered the influence of head tracking on the localization of auditory events. Recordings were conducted of impulse responses from a five-channel loudspeaker set-up in two different acoustic rooms. Results revealed that head tracking increased sound externalization, but that it did not overcome the room-divergence effect.
Heiko Purnhagen from Dolby Sweden, in a paper called “Parametric Joint Channel Coding of Immersive Audio,” described a coding scheme that can deliver channel-based immersive audio content in such formats as 7.1.4, 5.1.4, or 5.1.2 at very low bit rates. Based on a generalized approach for parametric spatial coding of groups of two, three or more channels using a single downmix channel, together with a compact parametrization that guarantees full covariance re-instatement in the decoder, the coding scheme is implemented using Dolby AC-4’s A-JCC standardized tool.
Hardware Choices for Post Users
Several manufacturers demonstrated compact near-field audio monitors targeted at editorial suites and pre-dub stages. Adam Audio focused on their new near/mid-fieldS Series, which uses the firm’s ART (Accelerating Ribbon Technology) ribbon tweeter. The five models, which are comprised of the S2V, S3H, S3V, S5V and S5H for horizontal or vertical orientation. The firm’s newly innovated LF and mid-range drivers with custom-designed waveguides for the tweeter — and MF driver on the larger, multiway models — are powered by a new DSP engine that “provides crossover optimization, voicing options and expansion potential,” according to the firm’s head of marketing, Andre Zeugner.
The Eve Audio SC203 near-field monitor features a three-inch LF/MF driver plus a AMT ribbon tweeter, and is supplied with a v-shaped rubberized pad that allows the user to decouple the loudspeaker from its base and reduce unwanted resonances while angling it flat or at a 7.5- or 15-degree angle. An adapter enables mounting directly on any microphone or speaker stand with a 3/8-inch thread. Integral DSP and a passive radiator located at the rear are said to reinforce LF reproduction to provide a response to 62Hz (-3dB).
Genelec showcased The Ones, a series of point-source monitors that are comprised of the current three-way Model 8351 plus the new two-way Model 8331 and three-way Model 8341. All three units include a co-axial MF/HF driver plus two acoustically concealed LF drivers for vertical and horizontal operation. A new Minimum Diffraction Enclosure/MDE is featured together with the firm’s loudspeaker management and alignment software via a dedicated Cat5 network port.
The Neumann KH-80 DSP near-field monitor is designed to offer automatic system alignment using the firm’s control software that is said to “mathematically model dispersion to deliver excellent detail in any surroundings.” The two-way active system features a four-inch LF/MF driver and one-inch HF tweeter with an elliptical, custom-designed waveguide. The design is described as offering a wide horizontal dispersion to ensure a wide sweet spot for the editor/mixer, and a narrow vertical dispersion to reduce sound reflections off the mix console.
To handle multiple monitoring sources and loudspeaker arrays, the Trinnov D-Mon Series controllers enable stereo to 7.1-channel monitoring from both analog and digital I/Os using Ethernet- and/or MIDI-based communication protocols and a fast-switching matrix. An internal mixer creates various combinations of stems, main or aux mixes from discrete inputs. An Optimizer processor offers tuning of the loudspeaker array to match studio acoustics.
Unveiled at last year’s AES Convention in Paris, the Eventide H9000 multichannel/multi-element processing system has been under constant development during the past 12 months with new functions targeted at film and TV post, including EQ, dynamics and reverb effects. DSP elements can be run in parallel or in a series to create multiple, fully-programmable channel strips per engine. Control plug-ins for Avid Pro Tools and other DAWs are being finalized, together with Audinate Dante, Thunderbolt, Ravenna/AES67 and AVB networking.
Filmton, the German association for film sound professionals, explained to AES visitors its objective “to reinforce the importance of sound at an elemental level for the film community.” The association promotes the appreciation of film sound, together with the local film industry and its policy toward the public, while providing “an expert platform for technical, creative and legal issues.”
Lawo demonstrated the new mc²96 Grand Audio production console, an IP-based networkable design for video post production, available with up to 200 on-surface faders. Innovative features include automatic gain control across multiple channels and miniature TFT color screens above each fader that display LiveView thumbnails of the incoming channel sources.
Stage Tec showed new processing features for its Crescendo Platinum TV post console, courtesy of v4.3 software, including an automixer based on gain sharing that can be used on every input channel, loudness metering to EBU R128 for sum and group channels, a de-esser on every channel path, and scene automation with individual user-adjustable blend curves and times for each channel.
Avid demonstrated native support for the new 7.1.2 Dolby Atmos channel-bed format — basically the familiar 9.1-channel bed with two height channels — for editorial suites and consumer remastering, plus several upgrades for Pro Tools, including new panning software for object-based audio and the ability to switch between automatable object and buss outputs. Pro Tools HD is said to be the only DAW natively supporting in-the-box Atmos mixing for this 10-channel 7.1.2 format. Full integration for Atmos workflows is now offered for control surfaces such as the Avid S6.
There was a new update to Nugen Audio’s popular Halo Upmix plug-in for Pro Tools — in addition to stereo to 5.1, 7.1 or 9.1 conversion it is now capable of delivering 7.1.2-channel mixes for Dolby Atmos soundtracks.
A dedicated Dante Pavilion featured several manufacturers that offer network-capable products, including Solid State Logic, whose Tempest multi-path processing engine and router is now fully Audinate Dante-capable for T Series control surfaces with unique arbitration and ownership functions; Bosch RTS intercom systems featuring Dante connectivity with OCA system control; HEDD/Heinz Electrodynamic Designs, whose Series One monitor speakers feature both Dante and AES67/Ravenna ports; Focusrite, whose RedNet series of modular pre-amps and converters offer “enhanced reliability, security and selectivity” via Dante, according to product specialist for EMEA/Germany, Dankmar Klein; and NTP Technology’s DAD Series DX32R and RV32 Dante/MADI router bridges and control room monitor controllers, which are fully compatible with Dante-capable consoles and outboard systems, according to the firm’s business development manager Jan Lykke.
What’s Next For AES
The next European AES convention will be held in Milan during the spring of 2018. “The society also is planning a new format for the fall convention in New York,” said Moses, as the AES is now aligning with the National Association of Broadcasters. “Next January we will be holding a new type of event in Anaheim, California, to be titled AES @ NAMM.” Further details will be unveiled next month. He also explained there will be no West Coast AES Convention next year. Instead the AES will return to New York in the autumn of 2018 with another joint AES/NAB gathering at the Jacob K. Javits Convention Center.