HOLOPLOT: The Challenge Of Creating A Sound System For Sphere, Part 2

Berlin-based HOLOPLOT was chosen for Sphere Las Vegas for its groundbreaking 3D Audio-Beamforming and Wave Field Synthesis technology. The project was particularly challenging because of the shape of the structure, the need for unobstructed sight lines with no large hanging arrays obscuring the view or interrupting the projection surface, and a sound system that worked well for both live performances and immersive films.

RELATED: HOLOPLOT's Unique Capabilities Transform Audio Experience At Sphere, Part 1

In the second part of Live Design's interview with Miguel Hadelich, head of sales and operations at HOLOPLOT USA, he talked us through the major challenges of the project, the pressures facing live venues, and his thoughts on the future of audio technology.

Live Design: The curved surface of Sphere is one obvious challenge to the audio, how did you address this?

Miguel Hadelich: Sphere is the largest, self-supported spherical structure in the world. It stands 366’ tall, has a 1000,000 m3 internal volume and the LED interior results in a six second RT. The sound must travel up to 110 meters to reach every member of the audience. HOLOPLOT technology enables the precise steering of sound on both the vertical and horizontal axes, allowing it to be contained within defined zones, preventing undesired energy spillage onto any room boundary and therefore significantly improving speech intelligibility and audio quality.

Inside a spherical structure, sound waves are naturally reflected towards the center, affecting the distribution and quality of audio. Conventional loudspeaker solutions like line arrays cannot prevent sound energy hitting reflective surfaces such as the highly reflective LED media plane at Sphere. This results in poor sound quality and distracting echoes.The brief for Sphere was not only to deliver crystal-clear audio for an audience of up to 18.600, but also to completely hide the sound system behind a 160.000 square foot, curved LED surface and deliver even sound coverage across a distance of 110m without the use of delay towers to ensure an unobstructed view.

Sphere’s proscenium array is mounted directly behind the stage, which thrusts out into the audience area by a fair amount. The curvature of Sphere means that the proscenium array is physically pointing down towards the stage, not up towards the audience area. However, 3D Audio-Beamforming technology means that sound can be digitally ‘aimed’ towards the audience. By building arrays in two dimensions (instead of traditional “line arrays”) there is control over the breadth and depth simultaneously, allowing coverage over a large and complex audience area.

HOLOPLOT has developed proprietary compensation algorithms to retain the characteristic clarity of sound of X1 by compensating for the angle-dependent and frequency-dependent transmission loss created by the LED screen. The effects can be described similarly to those of a directional-dependent, spatial EQ.The straight position of the X1 arrays keeps all sound sources (drivers) at a constant distance and angle relative to the screen. As a result, the transmission loss in a certain direction is the same for all drivers, allowing a uniform compensation across the array.

LD:  What other challenges were there on this project?

MH: HOLOPLOT’s work on the system for Sphere began in 2018 and simultaneously saw the development of the X1 Matrix Array, the technology behind Sphere Immersive Sound.

X1 employs a previously unheard-of number of drivers, each individually driven and signal processed. The mission was to build an acoustic prototype of X1 for Sphere in just four months so the viability of a design proposal could be validated. From there, its development was continued.

A big challenge was taking the extremely high-level project requirements and breaking them down into a product design and system concept that not only sounds and works perfectly, but ensured it was possible to mass manufacture within certain cost parameters. To be able to do this, the development team was grown from an initial five people to more than 40 in just a year. The entire company now numbers approx 140 employees.

Key milestones had to be reached throughout the process, with acoustical consultants Vanguardia overseeing the validation process. During the construction process, each cabinet was tested at our facility in Berlin, tested again when it was taken out of the shipping container in the US, and again when it reached Sphere.

LD: U2 are currently in residence in Sphere, will the sound system be left as is for the next artist?

MH: The sound system is permanently installed and will not require physical adaptation. Our technology is powered by software, so any changes to how the system is used can be made digitally, at the click of a button.

The sound system has two venue coverage modes that are instantly recallable by operators and/or the show control system: Full Venue Coverage Mode which sets each Sphere Immersive Audio Array to cover the entire venue evenly, and is the mode used for the U2 shows; and Immersive Coverage Mode for the 10,000 immersive seats, which sets the coverage pattern of each array and is currently used for (the movie)  Postcards from Earth.


The advantage of the Immersive Coverage Mode is that the sound quality is much more intimate as the sound system minimizes acoustic reflections resulting in sound that seems like it is coming from nearfield speakers and is unique to Sphere. Each Coverage Mode has variations that automatically adjust and compensate for changes in atmospheric conditions such as temperature and humidity, which allows the venue to have a consistent sound quality no matter what the current environmental conditions are. Any future shows or residencies can decide how they’d like to utilize the system. The creative opportunities are limitless.

LD: Do you think this advanced audio experience will create a demand from audience members in other venues?

MH: Yes, absolutely. Sphere has catapulted our industry into the future. It completely redefines the term live entertainment. People like to come together and share in their experiences, yet feel like the show is put on just for them. To achieve that it’s crucial to feel connected to the performance. Unintelligible or simply extremely loud live sound doesn’t allow you to do that. Most people now have access to incredibly high quality TVs and speakers at home, so live experiences have to match this.

HOLOPLOT allows venues to deliver the audio as it was intended, without the need to crank up the system to reach the rows at the back. Everyone receives the same listening experience. In Sphere this means people were able to pick out elements of a song they’ve never been able to hear before. Headphones and home hi-fi systems are so advanced, when we get to a live gig we want the same quality. It’s no longer sufficient to simply go and ‘see’ the artist, you also want to be able to connect to the lyrics, and this requires an advance audio solution, especially in venues of extreme scale.

LD: Do you think that advances in immersive sound will make these types of audio upgrades more affordable?

MH: All live venues strive to provide quality entertainment. Sphere has taken this premise and pushed the boundaries of what’s possible, showing us the future of live entertainment. Artists, sound designers and audiences are increasingly demanding immersive experiences, and are willing to pay extra for it. So while the initial investment might be higher, it pays off for a venue as they can cater to a broader program. I see this trend gaining further momentum, and being able to create multi-purpose, highly-flexible venue spaces is key to accommodating this trend.

HOLOPLOT technology and its unique sound control capabilities enable the creation of these highly flexible venues. Reduced set up and change over times with our software-driven technology also enable them to accommodate more shows throughout the week. Reliability rises when changes are being automated. Our products are powered by software so any changes can be done via presets, rather than having to be executed manually by an on-site team.

All HOLOPLOT sound systems are also monitored remotely. Our smart software constantly analyzes the performance of your system and its components and our remote support team is ready to step in whenever needed.

Additionally, by being able to direct audio to where it is wanted and keeping it away from reverberant surfaces, we reduce the need for cost-intense acoustic absorption, while also freeing up creative and architectural visions.

The sound clarity that can be achieved with HOLOPLOT makes broadcasting content more straight forward, with less time needed to mix the content for live screening to other venues or home screens for example. This concept lends itself perfectly for the world of esports, where different sections of the audience could listen to different content, while simultaneously live streaming the event to audiences across the globe.

LD: Can this type of immersive sound be accomplished in outdoor venues, for example, sports stadiums?

MH: Some of the key advantages of HOLOPLOT technology cater to the needs often seen in stadiums. Like enabling precise sound control, meaning even the most challenging environments can be transformed into exceptional listening experiences.

HOLOPLOT technology creates unbeatable coverage across the entire audience delivering greater fidelity and intelligibility for all. Our products can cover large distances without a drop in level, meaning the need for delay towers is reduced. They can also be integrated behind LED walls. Both these capabilities enable unobstructed sight lines, a big element of sporting events and large live concerts, where screens play a big role.

A HOLOPLOT system gives you greater control over sound, despite changing room or space acoustics for diverse events, allowing the sound to match the size of the crowd. This opens up the door to offering more diverse programming, reducing downtime for a venue, increasing revenue streams.

LD: What do you see as the future of sound for live entertainment?

MH: The future of venues is marked by a shift from single-purpose spaces to multifaceted destinations, integrating culture, hospitality, sports, and leisure. These venues will feature adaptable physical and virtual spaces, own media channels, engagement programs, and advanced technology systems to create memorable, connected (in the emotional and digital sense) experiences for their audiences. Permanently installed sound systems that provide flexibility and longevity are also a key component in addressing sustainability ambitions by preventing the need for transporting sound systems across the globe.

Audio technology is increasingly merging with visual technology and at HOLOPLOT we’re at the forefront of this. The venues of the future will become more and more dynamic, hosting diverse programs around the clock. Customer dwell time is being increased by offering a journey pre- and post-show, with integrated dining and breakout events. Our technology allows you to reconfigure a system at the click of a button, rather than having to physically change the audio system, making for an efficient changeover between events.

As we’ve seen with Sphere, immersive experiences drive innovation, and I’m sure we’ll see plenty more radically new interpretations of this. Especially with the dawn of AI and virtual content.

LD: What part of the Sphere project are you most proud of?

MH: The feedback from concert goers and industry figureheads like Joe O'Herlihy has been amazing. They prove that what we created has had the desired impact. The Sphere project has showcased HOLOPLOT’s ability to develop, build, and deploy a brand new technology successfully in such a short time. The system has redefined sonic experiences for live entertainment and, in addition to Sphere, has also been transforming venues around the world. All with their own unique challenges, of different sizes and with differing content. I look forward to continuing to bring unparalleled audio experiences to even more spaces.

LD: What other projects is HOLOPLOT involved in?

MH: Highly acclaimed sound designer, Jonathan Deans, collaborated with music supervisor Dean Sharenow and director Saheem Ali to create an unforgettable auditory experience for the Off-Broadway production of Buena Vista Social Club at the Atlantic Theater. Global technology provider PRG provided a comprehensive audio and lighting solution for the production, including the first HOLOPOT X1 system to grace a musical theater production.The Atlantic Theater is a converted church, with architecture that poses acoustic challenges. Although it has undergone significant modifications to become a delightful space for any show, accommodating live percussion instruments on stage, including congas, bongos, and timbales, sometimes just six feet away from the audience, meant it became inevitably loud. Deans was concerned about the vocal presence of the actors and needed precise audio control over the seating area, with vocal clarity amid live percussion being his main priority, which is why he specified HOLOPLOT.Utilizing HOLOPLOT’S proprietary 3D Audio-Beamforming and Wave Field Synthesis technology, X1 allows for the creation of precise coverage zones for the audience as well as sound localization in 3D space. The combination of this proved essential for managing vocal presence in a tight and potentially loud space without overwhelming the audience and led to Deans using X1. A single central mono cluster of three X1 modules is configured horizontally, and exclusively designated for vocal reinforcement, utilizing the system in a unique, creative and impactful way

LD: What other projects has HOLOPLOT been working on?

MH: The Beacon Theatre on Broadway is one of New York’s most prestigious and popular entertainment venues, hosting the biggest names in live entertainment. However, it has also been one of the most acoustically challenging with a plethora of hard, reflective surfaces and architectural restrictions making it extremely difficult to achieve even coverage and optimal sound.

In 2022, venue owners Madison Square Garden Group (MSG) decided to match the beautifully restored interior and high-caliber of touring acts with a cutting-edge sound system that would provide the best audio experience to every seat. The system design for Sphere was already well underway when the Beacon system was installed and the two systems don’t relate in that sense, rather the Beacon system was to provide artists and crew with an opportunity to get hands-on with a system they may encounter if performing at Sphere in the future.

X1’s modular design makes it scalable and flexible, delivering revolutionary audio experiences in any given space, whether for a 3000 cap theatre in a stereo L/R deployment or a 19.000 cap immersive mega venue.

Other notable projects include Misr Masjid, a newly-built mosque of incredible scale, central to the development of the country’s new administrative capital outside of Cairo, and London’s Lightroom, which hosts unique exhibitions, created in collaboration with leading artists and innovators.

As one of the largest mosques in the world, the Misr Masjid project presented the unique challenge of delivering clear, intelligible speech to a congregation of thousands in a space of over 10.000sqm - without compromising the architectural integrity of the building’s mainly marble interior.

A conventional sound system may require upwards of 30 positions to achieve sufficient coverage and intelligibility within such a space. HOLOPLOT provided unmatched audio coverage throughout the mosque, requiring only nine loudspeaker array positions. Each array is mounted as high as 23m above the floor, concealed at a significant distance from the listener behind painted cloth or metal, rendering the entire audio system invisible to worshipers.

X1 has the ability to perfectly control and shape sound in both classic and more complex environments, maneuvering highly reflective spaces with unprecedented accuracy. At Misr Masjid, X1 handled an existing reverberation time of six seconds, caused by both the marble interior and 60m high dome, managing not to excite the reverberant field - directing energy away from reflective surfaces and preventing the need for large amounts of acoustic treatment.

London-based Lightroom is an ambitious concrete structure housed in a 14m deep basement, allowing for projections up to 11m high, which was conceived by award-winning design studio and production company 59 Production, who wanted to turn it into a smooth sounding gallery space without compromising the 360-degree visuals. The team quickly realized that conventional loudspeaker solutions would need multiple wall cavities or mounting positions on all four walls to achieve the desired immersive effects. The space also has a reverb time of over six seconds and there is very audible background noise of projector fans. Sound Designer, Gareth Fry, suggested HOLOPLOT and a system design that only required two positions within the room, yet delivered more creative tools that could be used to generate immersive effects. The system not only provided the answer for the inaugural exhibit, ‘DAVID HOCKNEY: BIGGER & CLOSER (not smaller and further away)’, but also paved the way for future shows.The system design comprises two HOLOPLOT X1 arrays at either end of the room. HOLOPLOT’s unique optimization algorithms, means the listening area can be defined as well as the relative sound pressure level for each area. This allows for uniform coverage from each array no matter where the listener is positioned within the space. Additionally, each array is strategically placed behind color-matched, acoustically transparent material, which preserves the integrity of the 360-degree projection surface.