Reflections on Sir Harold Marshall's "The objective of acoustical design"

When reflecting on my career path, a few extraordinary individuals I had the good fortune to encounter have shaped my strong appetite for innovation and creativity. Creative people radiate energy and enlightenment, inspiring me to view our professional work in new ways. Sir Harold Marshall is one of them.

Impressions of Sir Harold Marshall

In February 2015, Sir Harold Marshall and I attended MDA's biennial conference in Adelaide

My initial encounter with Harold was through several email exchanges during the design process of the Zhuhai Opera House when employed by Marshall Day Acoustics. Later, I met him three times: twice at the company's biennial conferences, and once during a dinner in Hong Kong when he was passing through the city.

Harold is not tall, speaks at a measured pace, and carries himself with the demeanour of a philosopher. At the first biennial conference I attended, he gave a presentation. The philosophical depth of his talk was such that, although I understood each word individually, I found the overall meaning elusive. I asked a few colleagues afterwards, and was somewhat comforted to learn that they had also struggled to grasp the full meaning.

During a dinner in Hong Kong, while discussing the contributions of various teams to the acoustic design of the newly completed Philharmonie de Paris, Harold remarked, "The successes in good projects are shared." In the competitive corporate world, this statement struck me profoundly.

The Role of Acoustic Consultants in Auditorium Design

In the process of auditorium design, the role of acoustic consultants can be categorised into two main types. The first type makes local adjustments and refinements to a relatively mature architectural design. The second type collaborates closely with architects from the very beginning, creating a performance space that creatively integrates architecture, sound, and performance. The vast majority of acousticians fulfill the first role. Only a few possess the capability, opportunity, and ambition to perform as the latter, and Harold is undoubtedly a distinguished representative of this second type.

From his first notable work, the Christchurch Town Hall in New Zealand in 1972, to the Segerstrom Center for the Arts in the United States in 1986, the Guangzhou Opera House in 2011, and the Philharmonie de Paris in 2015, Harold has creatively applied his lateral reflection theory, first proposed in 1967. Working alongside architects, he has broken through traditional forms of performance spaces, creating venues with excellent acoustics that are both innovative and refreshing. His contributions to both the theory and practice of auditorium acoustics are outstanding.

The Christchurch Town Hall in New Zealand (Source: Marshall Day Acoustics website)

The Segerstrom Center for the Arts in the United States (Source: Marshall Day Acoustics website)

In October 2015, the 9th International Conference on Auditorium Acoustics was held at the newly completed Philharmonie de Paris. During this conference, Harold was awarded the prestigious Rayleigh Medal by the Institute of Acoustics and was invited to deliver the keynote speech titled "Presentational Rhetoric in Concert Halls: Being There - The Objective of Acoustical Design."

First Principles Thinking vs. Comparative Thinking

Harold’s keynote speech reflects his consistent philosophical approach, which seeks to understand the essence of a subject. This brings to mind Elon Musk’s emphasis of "first principles" thinking.

In a TED talk, Musk attributed his success across various fields to his mastery of first principles thinking: each system contains fundamental propositions or assumptions that cannot be omitted, deleted, or violated. First principles thinking involves stripping away layers of surface-level details to reveal the core essence of a subject, then building up from there. Musk argues that using first principles thinking rather than comparative thinking is crucial.

Most acousticians are accustomed to comparative thinking, which involves learning from the specific forms and details of successful auditoriums and then imitating them in their designs. This approach helps quickly grasp basic methods and reduce design errors, but it can also easily constrain designers within existing forms, leading to formulaic designs.

Harold never explicitly mentioned the concept of first principles, but it is obvious to me he thinks in this way. Using conventional patterns as a starting point for auditorium design clearly does not align with first principles thinking and is something Harold rejects. He wrote, "There is not much design required to follow a recipe! It is no accident that the "Shoeboxes", "Fans", "Vineyards" and so on were specifically excluded in the competition for the Philharmonie de Paris. A DESIGN was required".

Acoustic Design Objectives for Concert Halls

In his speech, Harold defines a concert hall as a form of art where performers and audience interact and derive meaning. This form of art, like painting, music, and dance, cannot be described abstractly in words but must be experienced in person. From this, he concludes that enhancing the impact of performances should be the common goal for all involved in the design of concert halls, including acousticians.

In the design process of concert halls, some acoustic consultants limit their responsibilities to calculations and analyses rather than actively participating in the design. Meanwhile, some architects focus solely on visual effects, neglecting the importance of acoustic design. This often leads to conflicts between architects and acoustic consultants. However, if both parties adopt "enhancing the impact of performances" as their common goal, they can collaboratively create a space that integrates architecture, sound, and performance, fostering a meeting of minds rather than a clash of wills.

Methods of Acoustic Design for Concert Halls

After reaching a consensus on design objectives, Harold addresses the next challenge: how architects and acousticians can resonate with each other in their design methods.

Architectural design encompasses various schools of thought and styles. However, a widely accepted approach among architects is to let the building become what it wants to be. Harold advocates that acousticians should also think about design in this way, allowing the building to become what it wants to be acoustically.

The difference between making a building what we want it to be and allowing it to become what it wants to be is significant. The former involves imposing our will on the building’s form, such as rigidly applying conventional hall shapes and treatments. The latter requires understanding, respecting, and leveraging the various forces at play in the design, guiding the building to achieve its ultimate acoustic goals. This transforms acoustic engineering into acoustic "design".

Harold illustrates how acoustic and architectural design can be unified through two of his projects: Guangzhou Opera House and Philharmonie de Paris. Both projects received widespread acclaim for their architectural effects and acoustic quality, and they both are highly innovative.

In the design of the Guangzhou Opera House, the architect Zaha Hadid aimed to break away from traditional symmetrical auditoriums, creating a dynamic, asymmetrical performance space. Harold valued this idea, noting, "The sound radiation of a symphony orchestra is not symmetrical; there is no reason why an auditorium must be symmetrical." He proposed a design concept where the seating areas were staggered to provide lateral reflections. Thus, the left-side balcony front could provide as many lateral reflections as possible to the right-side seating, and the right-side balcony front could do the same for the left-side seating. This unified the visual form of the space with its acoustic requirements.

The Guangzhou Opera House (Source: Marshall Day Acoustics website)

In the design of the Philharmonie de Paris, the architect Jean Nouvel envisioned a space rich with unpredictability. Building on this concept, Harold introduced the idea of an interwoven dual-space acoustic design. The inner space, composed of floating cloud-like reflectors and audience balconies, provides early reflections to enhance sound clarity. The space behind these reflectors and balconies contributes to reverberation, enriching the sound. Harold described the effect of the integrated architectural and acoustic designs as: "You cannot look at this space either and say ' the acoustics begins here... or there' ".

The Philharmonie de Paris (Source: Marshall Day Acoustics website)

Essential Skills and Qualities for Acoustic Consultants

To achieve acoustic "design", which the auditorium acoustically becomes what it wants to be, Harold identified the following essential skills and qualities acoustic consultants should process:

1. Deep understanding of objective acoustic criteria: Recognise the limitations of research on acoustic criteria. Understanding the derivation of these criteria allows surpassing conventional wisdom.

2. Understand impact of lateral reflections on the hall's geometric dimensions.

3. Open attitude towards architectural design: Avoid acoustic recommendations that compromise architectural vision.

4. Awareness of acoustic scale relating dimension to reflection bandwidth must be second nature.

5. Understanding the relationship between reverberation and volume.

6. Ability to identify surfaces prone to echoes.

7. Awareness of the limitations of ray tracing method for acoustic analysis.

8. Ability to communicate with the architects in their chosen medium: Use sketches or real-time 3D acoustic analysis to convey ideas.

9. Knowledge of acoustic materials

10. Aspiration to create spaces that enhance the impact of performances for performers and audiences.

Factors Determining the Reputation of Concert Hall Acoustics

Do concert halls with equally effective acoustic designs on a technical level receive the same acclaim for their sound quality? Harold's answer is no. While acoustic science and technology are necessary, they are not sufficient for the reputation of concert hall acoustics.

Harold categorises the factors determining the reputation of concert hall acoustics into four levels: physics, engineering, design artistry, and discursive power. Physics and engineering technology form the foundation—linear, predictable, and deducible. Design artistry and discursive power, however, are non-linear, complex, and unpredictable. As with all non-linear systems, a small perturbation can cause significant differences in outcomes. The superstructure is built on the foundation and cannot violate its principles, but the foundation cannot fully explain the superstructure's influence.

For example, some concert halls may be hailed by the media as having the best acoustics in the country. This recognition affirms the quality of their sound, but it does not mean that other halls cannot match their acoustic excellence on a physical level. Similar to how a film's success at the Oscars depends not only on its quality but also on its promotional efforts, publicity can sometimes be decisive.

Understanding these factors helps acoustic consultants better position themselves and their work within the broader context of auditorium acoustics.

The Significance of Harold’s Acoustic Design Philosophy

Harold is a world-renowned master in acoustic design, and his ideas are highly respected by both architects and clients. However, most acoustic consultants have limited creative freedom in their projects. Performing our duties diligently within these constraints is meaningful and necessary for most architectural projects.

Nonetheless, Harold’s acoustic design philosophy holds significant value. It reminds us not to focus solely on studying and imitating the specific forms of successful projects but to delve into the first principles behind these forms. Harold's design inspiration also teaches us to guard against falling into routine design patterns as we gain experience. We should strive to avoid mental rigidity and continually pursue innovation.

Even a small innovation can bring joy that transcends an award. I firmly believe that the joy brought by creativity is embedded in our DNA.