AES Europe 2025

In this session, we propose a path for the evolution of immersive audio technology towards accelerating commercial deployment and enabling rich user-end personalization, in any linear or interactive entertainment or business application. We review an example of perceptually based immersive audio creation platform, IRCAM Spat, which enables plausible aesthetically motivated immersive music creation and performance, with optional dependency on physical modeling of an acoustic environment. We advocate to alleviate ecosystem fragmentation by showing: (a) how a universal device-agnostic immersive audio rendering model can support the creation and distribution of both physics-driven interactive audio experiences and artistically motivated immersive audio content; (b) how object-based immersive linear audio content formats can be extended, via the notion of Acoustic Objects, to support end-user interaction, reverberant object substitution, or 6-DoF navigation.

This tutorial is for everyone working on the design or production of digital audio and should benefit beginners and experts. We aim to bring this topic to life with several interesting audio demonstrations, and up to date with new insights and some surprising results that may reshape pre-conceptions of high resolution.
In a recent paper, we stressed that transparency (high-resolution audio fidelity) depends on the preservation of micro-sounds – those small details that are easily lost to quantization errors, but which can be perfectly preserved by using the right dither.
It is often asked: ‘Why should I add noise to my recording?’ or, ‘How can adding noise make things clearer?’ This tutorial gives a tour through these questions and presents a call to action: dither should not be looked on as an added noise, but an essential lubricant to preserves naturalness.

Tutorial topics include: fundamentals of dithering; analysis using histograms and synchronous averaging; what happens if undithered quantizers are cascaded?; ‘washboard distortion’; noise-shaping; additive and subtractive dither; time-domain effects; inside A/D and D/A converters; the perilous world of modern signal chains (including studio workflow and DSP in fixed and floating-point processors) and, finally, audibility analysis.

This panel discussion gathers professionals with a broad range of experience across audio post production for film, television and visual media. During the session, the panel will consider questions around how AI technology could be leveraged to solve common problems and pain-points across audio post, and offer opportunities to encourage human creativity, not supplant it.

Broadcasting movies in linear TV or via streaming presents a considerable challenge, especially for highly dynamic content like action films. Normalising such content to the paradigm of "Programme Loudness" may result in dialogue levels much lower than the loudness reference level (-23 LUFS in Europe). On the other hand, normalising to the dialogue level may lead to overly loud sound effects. The EBU Loudness group PLOUD has addressed this issue with the publication of R 128 s4, the forth supplement to the core recommendation R 128. In order to have a better understanding of the challenge, an extensive analysis of 44 dubbed movies (mainly Hollywood mainstream films) has been conducted. These analysed films were already dynamically treated for broadcast delivery by experienced sound engineers. The background of the latest document of the PLOUD group will be presented and the main parameter LDR (Loudness-to-Dialogue-Ratio) will be introduced. A systematic approach when and how to proceed with dynamic treatment will be included.

In this workshop, we present the next generation of Immersive audio capture and reproduction through virtual acoustics. The aural room, whether real or generated, brings together the listener and the sound source in a way that fulfills both the listener’s perceptual needs—like increasing the impression of orientation, presence, and envelopment—and creates aesthetic experiences by elaborating on the timbre and phrasing of the music.
Members of the Immersive Audio Lab (IMLAB) at McGill University will discuss recent forays in creating and capturing aural spaces, using technology ranging from virtual acoustics to Higher Order Ambisonics (HOA) microphones. Descriptions of capture methods, including microphone techniques and experiments will be accompanied by 7.1.4 audio playback demos.
From our studio sessions, we will showcase updates to our Virtual Acoustics Technology (VAT) system, which uses active acoustics in conjunction with 15 omnidirectional and 32 bidirectional speakers to transport musicians into simulated environments. Workshop elements will include a new methodology for creating dynamically changing interactive environments for musicians and listeners, ways to create focus and “mix” sound sources within the virtual room, experimental capture techniques for active acoustic environments, and real-time electronics spatialization in the tracking room via the VAT system.
On location, lab members have been experimenting with hybridized HOA capture systems for large-scale musical scenes. We will showcase multi-point HOA recording techniques to best capture direct sound and room reverberance, and excerpts that compare HOA to traditional channel-based capture systems.

In this dynamic, hackathon-style session, participants will rapidly develop a world-class brand strategy for their company using cutting-edge AI tools and collaborative exercises. Attendees will leave with an actionable blueprint they can implement immediately in their businesses or projects.

Format: 90 minute session
Key Takeaways:
Master the essentials of brand strategy and its impact on content creation and sales
Engage in hands-on exercises to develop a brand strategy in real time
Learn how AI tools can accelerate brand positioning

Time selective techniques that enable measurements of the free field response of a loudspeaker to be performed without the need for an anechoic chamber are presented. The low frequency resolution dependent room size limitations of both time selective measurements and anechoic chambers are discussed. Techniques combining signal processing and appropriate test methods are presented enabling measurements of the complex free field response of a loudspeaker to be performed throughout the entire audio frequency range without an anechoic chamber. Measurement technique for both nar field and time selective far field measurements are detailed. The results in both the time and frequency domain are available and ancilliary functions derived from these results are easily calculated automatically. A review of the current state of the art is also presented.

Warsaw tutorial

Love it or hate it the Dolby noise reduction system had a significant impact on sound recording practice. Even nowadays, in our digital audio workstation world, Dolby noise reduction units are used as effects processors. 2
However, when the system first came out in the 1960s, there were other noise reduction systems, but the Dolby “Model A” noise reduction system, and its successors, still became dominant. What was it about the Dolby system that made it so successful?
This tutorial will look in some detail into the inner workings of the Dolby A Noise reduction system to see how this came about.
Dolby made some key technical decisions in his design, that worked with the technology of the day, to provide noise reduction that did minimal harm to the audio signal and tried to minimise any audible effects of the noise reduction processing. We will examine these key decisions and show how the fitted with the technology and electronic components at the time.
The tutorial will start with a basic introduction to complementary noise reduction systems and their pros and cons. We will the go on to examine the Dolby system in more detail, including looking at some of the circuitry.
In particular, we will discuss:
1. The principle of least treatment.
2. Side chain processing.
3. Psychoacoustic elements.
4. What Dolby could have done better.
Although the talk will concentrate on the Model 301 processor, if time permits, we will look at the differences between it, and the later Cat 22 version.
The tutorial will be accessible to everyone, you will not have to be an electronic engineer to understand the principles behind this seminal piece of audio engineering history.

Have you ever wondered how AES works? Let's meet up and talk about the benefits of volunteering and the path to leadership in AES! You could be our next Chair, Vice President, or even AES President!

This tutorial is based on a Journal of the Audio Engineering Society review paper being submitted.

2025 marks the centennial of the commercial introduction of the modern dynamic direct radiating loudspeaker, Radiola 104, and the publication of Kellogg and Rice’s paper describing its design. The tutorial outlines the developments leading to the first dynamic loudspeakers and their subsequent evolution. The presentation focuses on direct radiating loudspeakers, although the parallel development of horn technology is acknowledged.

The roots of the dynamic loudspeaker trace back to the moving coil linear actuator patented by Werner Siemens in 1877. The first audio-related application was Sir Joseph Lodge’s 1896 mechanical telephone signal amplifier, or “repeater.” The first moving coil loudspeaker was the Magnavox by Peter Jensen in 1915, but the diaphragm assembly resembled earlier electromagnetic loudspeakers. The Blatthaller loudspeakers by Schottky and Gerlach in 1920’s are another example of a different early use of the dynamic concept.

It is interesting to take a look at the success factors of the dynamic loudspeakers, creating a market for quality sound reproduction and practically replacing the earlier electromagnetic designs by the end of 1920s. The first dynamic loudspeakers were heavy, expensive, and inefficient, but the sound quality could not be matched by any other technology available then. The direct radiating dynamic loudspeaker is also one of the most scalable technologies in engineering, both in terms of size and production volume. The dynamic loudspeaker is also quite friendly in terms of operating voltage and current, and what is important, the sound can be adjusted through enclosure design.

The breadth of the applications of dynamic loudspeakers would not have been possible without the developments in magnet materials. Early dynamic loudspeakers used electromagnets for air gap flux, requiring constant high power (e.g., Radiola 104’s field coil consumed 8W, while peak audio power was about 1W). Some manufacturers attempted steel permanent magnets, but these were bulky. A major breakthrough came with AlNiCo (Aluminum-Nickel-Cobalt) magnets, first developed in Japan in the 1930s and commercialized in the U.S. during World War II. AlNiCo enabled smaller, lighter, and more efficient designs. However, a cobalt supply crisis in 1970 led to the widespread adoption of ferrite (ceramic) magnets, which were heavier but cost-effective. The next advancement especially in small drivers were rare earth magnets introduced in the early 1980s. However, a neodymium supply crisis in the 2000s led to a partial return to ferrite magnets.

One of the focus points of the industry’s attention has been the cone and surround materials for the loudspeaker. Already the first units employed relatively lossy cardboard type material. Although plastic and foam materials were attempted in loudspeakers from 1950’s onwards, plastic cones for larger loudspeakers were successfully launched only in the late 1970’s. Metal cones, honeycomb diaphragms, and use of coatings to improve the stiffness have all brought more variety to the loudspeaker market, enabled by the significant improvement of numerical loudspeaker modelling and measurement methods, also starting their practical use during 1970’s.

A detail that was somewhat different in the first loudspeakers as compared to modern designs was the centering mechanism. The Radiola centering mechanism was complex, and soon simpler flat supports (giving the name “spider”) were developed. The modern concentrically corrugated centering system was developed in the early 1930’s by Walter Vollman at the German Gravor loudspeaker company, and this design has remained the standard solution with little variation.

The limitations of the high frequency reproduction of the early drivers led to improvements in driver design. The high frequency performance of the cone drivers was improved by introducing lossy or compliant areas that attempted to restrict the radiation of high frequencies to the apex part of the cone, and adding a double cone. The introduction of FM radio and improved records led to the need to develop loudspeakers with more extended treble reproduction. The first separate tweeter units were horn loudspeakers, and the first direct radiating tweeters were scaled down cone drivers, but late 1950’s saw the introduction of modern tweeters where the voice coil was outside the radiating diaphragm.

The latest paradigm shift in dynamic loudspeakers is the microspeaker, ubiquitous in portable devices. By manufacturing numbers, microspeakers are the largest class of dynamic loudspeakers, presenting unique structural, engineering, and manufacturing challenges. Their rapid evolution from the 1980s onwards includes the introduction of rare earth magnets, diaphragm forming improvements, and a departure from the cylindrical form factor of traditional loudspeakers. The next phase in loudspeaker miniaturization is emerging, with the first MEMS-based dynamic microspeakers now entering the market.