The business of staging events, both indoors and outdoors, relies on a wide range of interconnected skills, technologies and services. All of these depend on the ongoing viability of live events.
Outdoor events such as festivals rely on and support a whole ecosystem of people and businesses. This includes the artists who perform, the organization and promotion of the event, the staging, design and production, the rigging, lighting, audio, visuals and effects, and the ticketing, security, refreshments, merchandise and transport. The list goes on. Live concerts can in many ways be broken down to being all about tickets and drinks. However, if we can’t stage the event, the tickets and beer can’t be sold, and the livelihood of many people will be dramatically affected.
The rising challenge
In today's world, staging events is not just about impressing audiences; it is also about meeting environmental and regulatory demands. Noise monitoring is de rigueur, and noise complaints have now become a major issue.
At d&b audiotechnik, this has always aligned with our mission: Democracy for Listeners. For over four decades, we have pursued one idea: that every audience member should feel the same connection to the music, regardless of where they stand or sit.
Controlling LF
Historically, the development of professional loudspeakers was a race to achieve higher output, greater power handling, and better durability. At the time, simply being louder than the crowd without bursting into flames by the end of the festival was already considered a great success! However, today's challenges demand more.
We now face complex acoustic spaces, high audience expectations in terms of intelligibility and consistency, and strict off-site noise limits. In professional audio, few challenges have been as complex or transformative as the pursuit of broadband directivity control, especially when extended into the low-frequency domain.
High and mid frequencies can be shaped with horns and waveguides. Low frequencies? Not so easy. Their long wavelengths radiate in all directions, spilling sound backstage, onto reflective surfaces or into off-site areas at outdoor events. Most critically in recent times, this has led to regulatory compliance issues related to environmental noise.
A 100 Hz problem and an idea
In 2013, a leading German outdoor festival received noise complaints from a nearby neighborhood. A 100 Hz peak was the cause of the complaints.
Our engineers asked: What if our ArrayCalc software could model sound not just in the audience zone, but all the way out to the affected area? We tried it and found that, by adjusting the time alignment of the main PA clusters, we could reduce the problematic frequency precisely where it mattered without affecting the audience experience.
This wasn't a complete solution, but it paved the way for further development.
In collaboration with SoundPLAN, we launched NoizCalc in 2016, giving users the power to predict offsite noise before the first speaker is even flown.
The SL-Series
The real milestone was reached in 2018 with the launch of the SL-Series, beginning with GSL, which was later joined by KSL and XSL. These were the first fully integrated, large-format loudspeaker systems to deliver true broadband directivity, using cardioid techniques in the low frequencies, within the same enclosure.
The SL-Series solved three long-standing challenges in loudspeaker design at once. Consistent coverage became a reality, with precisely defined horizontal and vertical dispersion from sub-bass to high frequencies, even below 100 Hz. Rear rejection reached new levels with up to 20 dB attenuation behind the array which was a real game changer for stage conditions and nearby residents alike. All of this was achieved within the framework of what we call 'System Reality': the seamless integration of loudspeakers, subwoofers, amplification and processing, resulting in improved system design efficiency, reduced implementation effort and accurately predictable performance across diverse environments.
What was once considered a theoretical limit in electroacoustic engineering became a true, full-range solution, in reproduced frequency range and directivity control.
Why It matters
Broadband directivity isn’t just an engineering success. It is also far from just being about “front-to-rear SPL difference”. For us, the focus is on delivering a consistent frequency response all around a system, that simply decreases in level the farther you move off-axis, without leaving sonic mud off to the side, which culminates in a significant overall level reduction behind the system. This creates a chain of benefits for everyone involved in live and installed sound. For system designers, the ability to deliver highly predictable coverage means greater precision in deployment and tuning, fewer reflections, and less need for corrective EQ or additional system design complexities. Artists on stage benefit from lower noise levels, clearer separation between front-of-house and monitoring, and more accurate reproduction of musical dynamics, all of which contribute to better performances and a stronger connection with the audience.
Event organizers and production companies see advantages in easier compliance with noise regulations, more consistent results across different venues, and the ability to deliver a higher-quality experience without unnecessary complexity. For the audience, directivity control that is truly broadband ensures a uniform tonal balance and sound pressure level across the entire listening area, even far off-axis. It also reduces reverberant energy and listening fatigue, creating a more engaging, emotionally resonant experience for audience members, no matter where they stand or sit.
Bringing it to smaller applications
SL-Series pioneered the application of cardioid techniques within a full-range cabinet to extend directivity control towards the lowest frequencies it reproduces, in this case, 45 Hz. It did that with a combination of ingenious electroacoustic design ideas and without increasing the amplification needs beyond 2-way active -which is an achievement we did not dare dream about before.
Yet not all events are mega-festivals or stadium shows. And while the size of venue or event does not reduce the need for broadband directivity control, it sure limits how much physical space and budget are available to achieve it. Thus, “Can you make it smaller?” quickly turns into “Can you make this work on only one channel of amplification?” for a solution to be commercially viable.
Drawing on our decade-long expertise in passive-cardioid systems, we managed to face even this challenge successfully - in 2025, we introduced the CCL (Compact Cardioid Line Array), which brought SL-Series precision to smaller venues, theatres, houses of worship, corporate events and broadcast studios.
In short, we're taking our "cardioid magic sauce" and making it accessible wherever great sound is needed.
More art. Less noise.
At our R&D hub in Backnang, we’ve chosen depth over breadth. We innovate with precision and a deep understanding of electroacoustic systems, rather than chasing mass-market shortcuts. This approach has shaped both our technology and our reputation.
In a world increasingly defined by environmental noise regulations and audience expectations for high-quality, consistent sound, the ability to precisely control how and where sound is distributed is not just a technical advantage but a necessity. There's a world of difference between sound that simply fills space and sound that connects, amazes and respects its surroundings.
d&b audiotechnik has proven that broadband directivity with low-frequency cardioid techniques is both technically achievable and commercially viable. Our vision has redefined what is possible and set a new industry standard.
As we extend this paradigm across our portfolio, the message is clear: the future of sound isn’t just louder and bigger. It’s smarter, more focused, and more intentional.
By Santiago Alcalá Baillie, Product Manager Loudspeakers at d&b audiotechnik