The physics of feeling: Inside the science and showcases of live sound pioneers L-Acoustics


I’m in a suburban office park and it feels like a music festival. I’m in a showroom and it feels like a concert hall. I’m in a 3,000-person auditorium and it feels like a 10,000-person arena. I’m outside of Paris, in London, and at the offices of sound reinforcement specialists L-Acoustics—on a multinational adventure to experience 40 years and the future of audio as a transformative medium.

It’s September 2024, four decades to the month that Dr. Christian Heil founded the sound solutions company in a farmhouse south of Paris. L-Acoustics systems can now be found on some of the most high-profile tours and in 10,000 iconic concert halls, cultural centers, events facilities, and festival grounds worldwide. 

I’m at the L-Acoustics headquarters in Marcoussis, another Parisian suburb, where I’ll learn about L-Acoustics’ approach to amplifying art and amplification as art. But to truly understand how the company has developed tools that give engineers full control of the sonic environment, I first have to imagine it’s 1977 and I’m facing a stage bathed in projections, topped with inflatables, and surrounded by massive, chaotic, messy speakers.

It’s a Pink Floyd concert, and an era where Heil felt sound was very necessary but not very celebrated. A Ph.D. in the field of particle physics, Heil felt that, while the “In the Flesh” tour was profound, he could use his understanding of how energy travels through mediums to improve electro-acoustics and how concert speakers vibrate particles on the way to moving our souls. So, in September 1984, he founded C.HEIL.TEA—the company that would become L-Acoustics—so he could apply the knowledge of what slows and slurs sound waves in order to engineer clearer expression and emotional engagement at live events.

Stacks towers walls—the way speakers were described shows that concert sound had always been building toward something. But building blocks are just that: Blocks. These cubes and columns sit beside, under, on top of each other, bolted to pre-existing architecture. They spit output in the same direction and interfere with each other. And making things louder did not make them clearer. The disjointed doubling of sound waves causes something called comb filtering, which can result in a hollow response that volume does not fill. 

Heil’s solution to the destructive sound patterns from these clusters was 1992’s Variable Curvature Line Source Array, or V-DOSC. This multi-speaker system used Wavefront Sculpture Technology to ensure consistent SPL throughout the audience, funnel the high frequencies into coherent beams, and produce intelligible sound at scale. 

Without a waveguide, sound ripples outward, becoming uneven and indistinct depending on the area. But when properly engineered and aligned, the reflectors in these vertical speaker stacks help deliver a flat, cylindrical wave of sound rather than a round, expanding one, minimizing drop-off. This, in turn, reduces volume hot spots and dead spots and paints an overall more balanced experience regardless of where you’re in the crowd. 

Presenting the high, mid, and low drivers as a single continuous source, V-DOSC was the first step from where things were—producing louder and louder speakers—to where they are—producing speakers that are not only sonically efficient but space efficient, cutting down on transportation and installation costs. Properly placed line arrays also narrow the space between performer and speakers, cutting down on the disconnect of seeing a band directly in front of you but hearing them coming from off to the sides. Even in a cavernous space, reconnecting sound and vision can make things seem more immediate and intimate. 

Line arrays are the standard now—if you’ve been to a mid-sized or large venue recently, you can’t miss the ribbons of black boxes flying above the stage, gently curling inward to make sure the audience can hear from GA to far away. Better dispersion at distance is the norm. If it sounds simple, it’s not. If it sounds awesome, that’s because it is. But before the L-Acoustics era, this wasn’t the case.

Of course, it’s one thing to talk concepts. It’s another thing to encounter them. We walk down the street to take a quick tour of the product lines (see the slideshow below), looking at the craftsmanship and quality control that ensure customer satisfaction. L-Acoustics has speaker, amplification, and DSP (digital signal processing) component facilities in France and Germany. But while manufacturing is spread out, final assembly takes place right here—keeping the supply chain and the signal chain proprietary for the sake of traceability and reliability. 

I’m then taken behind Marcoussis HQ, beyond the parking lot, and into the trees, where we can focus on focus and experience the innovations that set the stage—literally and figuratively—for live sound. It’s here, in a grove under the transmission towers, that L-Acoustics stages K and L Series speakers that require very understanding neighbors when they run one of these A/B test sessions. 

Walking me to, and through, these systems are Tom Laveuf, an L-Acoustics application engineer for Southern Europe, and Rahul Samuel, L-Acoustics head of application for Northern Europe. Both transitioned from playing on stage to manning the mix around the turn of the millennium, so have plenty of perspective when it comes to taming unruly reflections or uneven coverage—a process that was once as much guesswork as science. Now, however, you can sweat the details pre-arrival so you sweat less on-site.

“When I started as a system tech, we’d do everything in Microsoft Excel, putting numbers in there and trying to find the angles you needed to deploy to, the heights you want to put something at,” says Samuel. “And the tolerances weren’t always so tight, so you could have five of the same model loudspeakers, and they could all sound slightly different from each other. Thanks to modeling programs [like L-Acoustics Soundvision] and adjustable waveguides and working with a company with consistent sound quality enabling accurate predictions, now you can spend time on site finessing things, not fixing them.” 

Physical developments in the line arrays helped achieve this new level of control. With the K Series (released in 2008), L-Acoustics improved weight management and flexible rigging options, allowing adjustable angles between boxes for even smoother tailoring of vertical directivity. And with 2014’s K2, L-Acoustics introduced Panflex technology—mechanically adjustable “fins” visible along the trough in the middle of speakers below—that could work alongside DSP to steer horizontal coverage as needed to respond to venue width.

And with the L Series (introduced in 2023), the company took into consideration average venue and audience geometries to develop a streamlined design with optimum curve, power density, and off-axis performance, but reduced weight and materials (and therefore lower fuel costs and carbon footprint). A new auto-lock rigging system and single cable connector, among other factors, mean five times less action to get an array in the air. Computational fluid dynamics contributed to redesigning the internal volume to create bigger, better airflow, and, therefore, better bass. 

Despite all this, the cardioid pattern of the boxes minimizes low-frequency bleed if you’re not in front of the speakers, which is good for performers and staff and the stage behind you at a festival. After walking around the speakers while playing test tracks, stopping at designated angles to gauge efficiency and engagement, I can confirm its surprising effectiveness.

In general, prototyping with algorithmic digital twins led to many innovations. As important as the hardware is for tonal consistency, however, the sound wouldn’t be as exactingly sculpted without the pre-visualization of L-Acoustics software. Soundvision is 3D modeling software for a venue’s acoustic response, allowing engineers to import CAD models of spaces and simulate speaker confirmations. Considering virtual variables and potential obstructions gives actionable insight so engineers can optimize coverage and clarity before a single cable is laid. This makes for a shorter setup that’s all about precision, not panic. And once systems are soaring, real-time coverage pattern changes in software reduce physical adjustments required.

“With Soundvision, we could design systems that delivered consistent sound quality from the front row to the nosebleeds,” says Laveuf. “It changed our workflow, shifting from reactive problem-solving to proactive design.”

If there are mitigating factors, the control of an L-Acoustics system goes far beyond physical arrangements. When it comes to sound propagation, wind, temperature, humidity, and other environmental factors will have a discernible effect on sound projection. With software, you can map out where the energy is projected to be distributed and dented and compensate for frequency losses with granular adjustments. Wherever a few more dBs needs to be pushed, amplification channels are always on tap. 

Of course, all this control available to L-Acoustics’ 12,500 registered software users goes beyond mere convenience and can be used for creative purposes, as well. The L-ISA Immersive Sound Art allows for object-based audio, for specific elements to be moved throughout a three-dimensional sound field. While impactful for concerts, this spatial audio is particularly powerful in bespoke auditory experiences like Broadway productions, where directional cues are part of the narrative.  

When it comes to the L-Acoustics narrative, I leave Paris with half the story. Along with its use at Bon Iver concerts and Adele residencies, among so many others, L-ISA has found applications beyond performances and has been used in museums, corporate installations, and other shared spaces. But these are all planned and paced encounters. I arrive in London and head to the L-Acoustics Highgate facility ready to learn about the company’s latest technologies that allow spaces to be transformed at the press of a button.

The HYRISS platform exemplifies this vision of architectural audio, enabling venues to tailor their acoustic identity dynamically. Case in point, we’re ushered into a well-appointed sitting room, striking in its elegant simplicity. Velvet couches, impressionistic art and expressionistic carpet, and a flatscreen TV are to one side, small marble and gold tables and chair to the other, a piano in the divide. Sonically, it starts out a “blank canvas of quiet,” according to our host Scott Sugden, L-Acoustics director of product management. And you can’t always reshape the space that exists for sound, so why not reshape how the sound exists in a space.

HYRISS, or Hyperreal Immersive Sound Spaces, does just that; it lets you take the static space and match it to the context of the occupants. Walking around with an iPad, Sugden launched a standard stereo track into the dead air—first playing it throughout the room before moving it from one wall to one corner till he finally split its frequencies, with vocals and bass at opposing ends. Next a nature soundscape enveloped us as we wandered our serene sanctuary, until the ambiance was broken by the entrance of concert pianist Belle Chen. Teasing the keys, she and Sugden exchanged thoughts on the need for some resonance. And with a tap, reverb gave the piece she was playing the big hall energy it needed to breathe. 

“The goal is to make sound as adaptable and integrated as lighting,” says Sugden. “You can highlight, dim, or redirect sound based on the mood or activity.”

A comfortable space for casting those evocative hues requires an investment, of course. For this showroom, 60 speakers from the short-throw X Series and medium-throw S series are powered by 60,000 watts, all embedded in the walls and ceiling. At the same time, the control platform leverages L-ISA’s overall positional capabilities and Anima machine learning for the localization and spatialization of separate sonic elements. Finally, the Ambiance system uses custom-installed sensing microphones and processors to change the room acoustics—further sculpting the echoes and eddies in real time from speech-friendly to concert-ready. 

“We design the full stack of technology, and we manufacture the full stack, and that’s a huge help,” says Sugden. “You know, a Formula One car is so fast not because it’s naturally the fastest car, but because they’re integrating everything together. At the end of the day, that’s how you get that level of performance and how you do it consistently around the world. And that’s the reason why artists choose L-Acoustics … because around the world, the level of control we maintain means it’s going to be consistent.”

HYRISS is the kind of integration that could be done in a custom-build home cinema but would be equally suited to a conference center or gallery or theater or other multi-use “temples for the ears,” as Heil calls them. Why just fill the room when you can fulfill the room? It’s a question asked and answered again when I encounter one more L-Acoustics system later that night. 

I’m at ABBA “Voyage,” the virtual residency of the Swedish pop band in a purpose-built, engineered-wood East London venue full of L-Acoustics solutions. I’ve come for the kitsch but stayed for the kicks. There’s an infectious feedback loop as thousands of people sing along with the digital avatars (or ‘ABBAtars’), the room itself amplifying the escapism and making every new old song a happiest memory. It’s engineering meets artistry, immersive and articulate—the essence of L-Acoustics in its fifth decade. The company has four decades on the front line of line arrays, leading the first wave of waveguides, and is still finding new ways to re-engineer experiences.

“Good sound means connection,” says Heil earlier in the day. “It’s not just about fidelity or full frequencies; it’s about creating an environment where the audience feels emotionally engaged and present in the performance. That’s what we’ve dedicated 40 years to achieving—an environment where sound doesn’t just accompany life, but helps shape it.”

 

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