Giving Spaces New Meaning

May 29, 2024

Even if you've attended a concert or live performance, you might not realize what goes on behind the scenes. Sophisticated acoustic design plays a crucial role in ensuring that the artist's sounds reach every corner of the venue. That's why Yamaha has dedicated decades to researching acoustic design across different areas. This includes architectural acoustics for refining building interiors, as well as electroacoustics for enhancing equipment such as speakers.

In 2021, Yamaha combined and enhanced its existing technologies to introduce Active Field Control (AFC), a groundbreaking immersive sound solution. AFC consists of AFC Enhance, which optimizes the reverberation and spatial impression of a sound space, and AFC Image, which allows for precise control over localization of a sound. These technologies effectively turn the venue into a musical instrument, facilitating new forms of musical expression.

Taking Control of Ambience and Sound

Yamaha started researching acoustic design in 1969, aiming to discover the ideal relationship between performer, audience, and space. This led the company to establish an acoustic design consulting service for auditoriums and theaters across Japan.

The challenge at the time was to adjust the acoustic environment to suit diverse situations. For instance, in a church setting, the acoustic requirements for choir performances are different from those for sermons. Choir music benefits from a fuller resonance, whereas less reverb is preferred during sermons to enhance clarity of speech. "We needed a way to achieve multiple types of acoustic qualities within the same space," explains Hiromu Ohgi, who is currently involved in the AFC project.

The conventional approach to increasing resonance is to add artificial reverb effects. However, this changes the impression of the original sound of musical instruments and vocals. In 1985, Yamaha revolutionized the practice with the introduction of "Assisted Acoustics." By manipulating sound propagation within the space itself, it allowed for adjustments in reverberation and volume, while preserving the authentic quality of the original sounds. Following several technological upgrades, Assisted Acoustics evolved into AFC Enhance, offering users the ability to create ideal acoustic environments for diverse applications.

Meanwhile, AFC Image emerged from Yamaha's extensive research and development into its immersive sound solution, ViReal TM. While AFC Enhance controls the reverberation of a space, AFC Image offers three-dimensional control over the position and motion of individual sounds within the space. For example, AFC Image can give the audience the impression that they are hearing the music directly from the instrument itself, rather than through the speakers. It can also simulate the sensation of sound sources moving from one part of the stage to another. Creators can exert this level of control over 128 objects simultaneously, offering the audience dynamic and immersive acoustic experiences.

Unlocking the Potential of the Novel Technology

In 2021, Yamaha merged the two models and introduced the new system as AFC. Initially, the potential applications for this new technology were unclear.

The breakthrough occurred when Yamaha partnered with conductor Tomomi Nishimoto to explore AFC's capabilities in her classical concert. Ohgi explains, "Because of the COVID-19 pandemic, people were questioning the purpose of gathering together for concerts and live shows. Ms. Nishimoto addressed this by conceptualizing her concert around the idea of 'connecting spaces,' which resonated with AFC's ability to control acoustic space."

The concert, titled "Marinart Becomes a Forest," took place in October 2021 in Shizuoka, Japan. Pandemic restrictions prevented the chorus and orchestra from performing in the same space. AFC was used to connect the main hall with two other rooms in real-time, enabling the musicians to perform in a unified acoustic environment. AFC was also used to tell a story through music. Adjustments in reverberation and sound motions were used to portray the shifts in seasons, eras, and locations, immersing the audience in a captivating journey through time and space.

The performance offered valuable insights into the potential of the new technology. "Ms. Nishimoto provided us with many ideas and suggestions on how to use AFC to achieve the desired sound for each piece," Ohgi explains. "Her concert helped us better understand the wide range of potential applications.

Ohgi has been immersed in music from an early age, playing various instruments like the electone, contrabass, and cello. At his first recital, he was captivated by the concert hall's acoustic qualities and felt inspired to create similar spaces one day. This childhood experience, combined with his interest in physics, led him to pursue a degree in acoustic engineering at university. During his internship at Yamaha, Ohgi found his passion for spatial acoustics, which ultimately led him to join the company. Today, he is involved in both acoustic design and AFC-related projects.

Space as a New Kind of Instrument

After gaining valuable insights from Ms. Nishimoto's concert, Ohgi and his team organized an AFC String Quartet Experimental Concert in 2022. "We collaborated with composer SiHyun Uhm, who composed the music with AFC technology in mind," Ohgi explains. "It marked the first time AFC was integrated into a musical piece, almost as if it were its own instrument." The acoustic effects made possible by AFC Enhance, along with the manipulation of acoustic images within the space using AFC Image, further expanded the range of musical potential.

By overseeing two innovative concerts, Ohgi reaffirmed his understanding of the role that sound space plays in music. Conventionally, music was limited by the physical attributes of the venue where it is performed. Because AFC offers control over the acoustic environment itself, it removes these physical constraints and allows for greater freedom in musical expression.

As evidence, Ohgi notes a shift in how AFC is utilized. "Initially, AFC was used passively, to refine the acoustic environment for a more natural experience," he reflects. "But as new methods of sound manipulation emerged, creators began harnessing AFC in more innovative and proactive ways."

Opening the Door to New Forms of Musical Expression

Many examples in history indicate that acoustic environments shaped the evolution of music. Ohgi elaborates, "I think the distinctive reverberation inside churches laid the foundation for church music, which eventually evolved into classical music. Conversely, Japanese gagaku music might not have spread as widely if the architecture were stone-based rather than wood-based."

As AFC empowers its users to control the acoustic space itself, it holds the potential to mark a pivotal moment in music history.

This is why Ohgi emphasizes the importance of making AFC accessible to as many sound engineers, composers, and creators as possible. "Engineers alone cannot shape the future of music," Ohgi emphasizes. "Composers and musicians are better positioned to unlock the technology's full potential." This is particularly true for AFC Image; being relatively new, its full potential remains undiscovered by engineers. Yamaha is dedicated to showcasing AFC's value to creators and encouraging its use.

Ohgi adds that it is equally important to support creators' artistic endeavors by refining the technology. "Currently, AFC can manipulate the reverberation and acoustic impression of the space, as well as the positioning of individual sounds. There are many elements that are still out of our control, however. Our ultimate aim is to achieve full control over all aspects of the acoustic environment." The collaborative efforts of engineers refining the tool and creators innovating its usage are certain to reshape music history.

AFC controls acoustic environments, opening new possibilities for musical expression. Meanwhile, Station Pianos use the power of music to transform train stations. While these endeavors may appear unrelated at first glance, they share the same goal of enriching people's musical experience through the synergy of space and sound. In the final article in this three-part series, we will look into the "Key" that connects these two projects. Stay tuned.

(Interview: December 2023)

*Bio as of the time of the interview