ECHO Project: A New Chapter in Immersive Orchestral Recording

The ECHO Project (Exploring the Cinematic Hemisphere for Orchestra) emerged from a shared ambition: to rethink how orchestral music can be captured in three dimensions, and to make that knowledge openly accessible to the wider community. Rooted in collaboration between leading engineers, researchers, and AIR Studios in London, the initiative brings together academic inquiry and industry expertise to explore new frontiers of spatial recording.

This project builds upon a simple but powerful idea: that immersive audio is not merely a technical enhancement, but a creative medium in its own right. When recording techniques faithfully capture the energy of an ensemble and the character of a space, listeners are invited not just to hear the orchestra, but to inhabit the performance.

A Recording Session Designed for Discovery

The team convened at Lyndhurst Hall at AIR Studios, a venue renowned for its unique acoustic signature and long history of film scoring. 

© Applied Psychoacoustics Lab (APL)

For this project, the London Contemporary Orchestra performed two contrasting works:

• Train Journey, a new composition by Academy Award–winning composer Volker Bertelmann (Hauschka), written expressly to explore immersive musical storytelling.
• Schreker’s Kammersinfonie, whose intricate textures and shifting colours pose a rewarding challenge for spatial capture.

To reveal the different possibilities of immersion, the orchestra was recorded in two physical configurations: a traditional 180° layout and a circular 360° arrangement that places performers around the microphone arrays. This dual approach enables listeners and researchers to compare how layout, composition, and recording technique interact to shape the listening experience.

Eight Microphone Arrays, Eight Perspectives

One of ECHO’s defining features is the diversity of microphone arrays contributed by the participating engineers. Rather than adopt a single standard, the project embraces the individuality of each designer’s philosophy, honed over years of recording for film, games, and classical music.

Among the arrays included are:

• 2L Prism (Morten Lindberg), refined for tonal transparency and natural balance.
• AirCage (Nick Wollage), extending the Decca Tree tradition into the immersive domain.
• ESMA-3D (Hyunkook Lee), designed for precise, continuous 360° imaging and VR rotation.
• P3H Anamorphic and P3H Pyramid (Mark Willsher), created to shape spacious, cinematic sound fields.
• PAMA (Simon Ratcliffe), tailored for Dolby Atmos workflows in contemporary scoring.
• PCMA-3D v2 (Hyunkook Lee), built on psychoacoustic principles of vertical localisation.
• PentaSphere (Anthony Caruso & Kellogg Boynton), inspired by spherical HRTF design and the PlayStation spatial audio ecosystem. 

Together, these arrays form a rare comparative resource: a set of eight professional interpretations of immersive orchestral capture, all recorded simultaneously under identical conditions.

A Comprehensive Open-Access Database

All materials from the session have been released open access under a CC BY-NC-ND 4.0 license, forming the ECHO database — an extensive library intended for education, research, and creative exploration.

The collection includes:

• The full multitrack recordings from every array, along with spot microphones, ambience arrays, a KU100 dummy head, and an EigenMike EM32.
• Dolby Atmos 7.1.4 ADM master files, prepared in both “array-only” and full “presentation” versions by each engineer.
• Binaural renders using the APL Virtuoso plugin, enabling accurate virtual playback of the spatial mixes on headphones.
• Pro Tools and REAPER session templates, allowing users to explore and remix the materials with ease. 

This open-access model continues the spirit of the previous initiative 3D-MARCo, reaffirming the value of sharing high-quality reference material with the wider community.

Advancing the Field of Immersive Music

Beyond its technical contributions, the ECHO Project invites a broader reflection on how orchestral music may evolve in an immersive landscape. It foregrounds the interplay between composition, spatial design, and microphone technique, demonstrating how each element shapes the listener’s sense of presence, scale, and narrative.

For students, engineers, and researchers, ECHO offers a rich foundation for study. For composers and producers, it offers a glimpse into new creative possibilities. And for listeners, it provides an opportunity to encounter the orchestra in a more enveloping, multidimensional form.

The project was made possible through the generous support of AIR Studios, Air Edel, HHB/Avid, Dolby, Dynaudio, Spitfire Audio, Audeze, Audiomovers, and many others, alongside the musicians of the London Contemporary Orchestra and conductor Hugh Tieppo Brunt.

© Applied Psychoacoustics Lab (APL)

A Year of Immersive Discovery

ECHO was designed to be a catalyst, sparking curiosity in practitioners just beginning their immersive journey while challenging seasoned professionals to rethink their established workflows. Over the past year, the project has matured into a vital ecosystem for educators, researchers, and sound engineers. It offers the community a rare opportunity to learn, compare, and combine techniques using materials of the highest quality.

By providing open access to recordings from a renowned studio space, captured through a variety of microphone arrays, and performed with the highest level of musicianship and composition, ECHO removes the usual barriers to entry. It allows users to experiment with professional-grade assets that are usually locked behind closed doors, bridging the gap between theoretical research and the practical realities of a recording session.

ECHO Use Cases

The ECHO Project resources have been used across a wide range of applications in both the professional audio industry and academia, for example:

• Choosing a microphone array for capturing enveloping ambience in a re-amping session at Abbey Road Studio 2, London, by Emre Ramazanoglu, mixer, producer, and songwriter.
• Teaching immersive orchestral recording techniques at Abbey Road Institute, London, by James Auwarter, recording and mixing engineer.
• Experimenting with diffusion strategies for spatial orchestral recordings, by John Pax, Managing Director, Harvard Shelemay Sound Lab, USA.
• Supporting decisions on experimental immersive microphone arrays for Dolby Atmos production of acoustic music, by Matt Anderson, engineer and owner of MillSounds Studio, USA.
• Exploring immersive recording techniques in an ensemble recording class, by Kazuya Nagae, Professor, Sound Media Composition Course, Nagoya University of the Arts, Japan.
• Teaching immersive mixing and critical listening, by Kieran Lynch, Lecturer in Sound and Music Production at the Institute of Art, Design and Technology (IADT), Ireland.

The Future of ECHO

As we move into the second year of ECHO, the focus shifts from data collection to broader community engagement and real-world application. To mark this milestone, we are planning a special online event that will invite feedback, explore how the resource has inspired engineers to experiment with new techniques, and discuss how ECHO can continue to grow as a hub for the immersive audio community.

We hope ECHO will serve as a valuable resource for anyone interested in immersive sound, from students and educators to composers and music lovers alike. The event will provide a space to share how the database is being used in both smaller- and larger-scale projects, examine the impact of composition, musicians positions and different microphone arrays on the creative process, and encourage dialogue between the technical and artistic sides of the industry. We invite you to download the tracks, join the webinar, and take part in shaping the sounding future of immersive productions.

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Visit: https://apl-hud.com/echo/