Loudspeaker Designer Roundtable

What are the most important sonic qualities you strive for in your designs?

Stereo imaging, detail, dynamics, tuneful bass. Most of all, the degree with which the listener can communicate with the performance. We don’t want a colored presentation, but the n^th degree of coloration is preferable to losing the values we strive for. There are many loudspeakers we have heard that are very analytical but fail to engage the emotion of the music.

What role does in-room listening play in the design process?

A very important one, over an extended period of time. Changing components, cables, damping material, etc. We listen to a varied selection of music but tend to have various tracks we use for reference. Where the speakers are not too large, we take them home to listen in different rooms on different systems. It’s important to take breaks from listening and do something else regularly. Your ears and brain get tired otherwise, and you lose focus.

Loudspeakers have improved dramatically in the last 20 years. Have we reached engineering limits, or are advancements still possible?

We will never reach the limits of what is possible, but with such a mature technology in general improvement can often be small. There are exceptions though. It does pay to be a bit of a loudspeaker historian, looking back at the work of Harry Olsen for example from the 1930s to 1970s. Olsen had over 100 patents and many of our modern ideas are in fact not new—the isobaric loudspeaker for one. With the benefit of modern materials and computer simulation, many old ideas can have a new lease of life.

What are the engineering challenges confronting loudspeaker designers, and do you expect any breakthroughs in the near future?

The greatest challenge is probably making better-sounding loudspeakers at a specific price point despite increasing costs, while maintaining quality. This does not necessarily mean manufacturing in Asia. New materials and manufacturing techniques all play a part. DSP is now an important part of many loudspeakers when used sensibly. We do not feel it is a means of turning a sow’s ear into a silk purse. It is hard to predict breakthroughs, perhaps a new loudspeaker motor system that is more efficient and more linear. We now have advanced computer modeling techniques to try ideas out more readily.

Daniele Coen

AlsyVox

Daniele Coen is the main designer and owner at AlsyVox, and his wife Paola is responsible for the aesthetics as interior designer. Daniele studied aerospace engineering with the idea of becoming an F1 Ferrari designer, but just before finishing his studies he fell in love with music reproduction. He has an unsatisfied love for music as he tried to be a madrigal singer with very limited success. He applied his technical background with a firm belief that most of the masterpieces of creation are still totally unknown and not understood.

Love for music and fascination for the unexplained drove him toward the path of speakers design in an unconventional way: dipoles, line sources, and ribbons. In parallel, he followed a career as designer, application engineer, inventor in multinational companies, and was later involved in marketing and sales, ending his career a few years ago when he decided to create AlsyVox with his wife Paola. They moved from Italy to Spain and now, after about 40 years spent in speaker development, their full-time occupation is making audio customers happy with their ribbon-planar speakers.

Do you consider loudspeaker design more of an art or a science?

There is quite a lot of science behind loudspeaker design, like vibration study, impedance in the interface between diaphragm and air, frequency response calculation and measurements, directivity patterns, distortion measurements, magnetic field calculation, mass distribution on the diaphragms, choice of materials and glues, vibration control in the structure, coupling or decoupling to the floor.

The list could cover the page, but at the end it is always a matter of musical taste and perception that rules the choices, both upfront choices (what type of speaker design we want to make, in our case dipole line source) and practical solutions on how to make it.

Our design procedure is probably 30% calculation, measurement, and science, and 70% art, musical taste, listening, design for function without strict scientific background.

What are the most important sonic qualities you strive for in your designs?

That is difficult to say because we take into consideration as many as we can, but if I have to pick four I would say coherency, dynamics, 3D reproduction, and frequency response. Coherency is widely related to musicality; we look for similar materials in all the transducers, similar physical extension of them at least in their length, same magnets, and, of course, same radiation pattern (dipolar). Dynamics are realized with lightweight moving parts and extended emission surface, as well as strong magnets. Three-dimensional reproduction has always fascinated us because it gives that strange sensation of physical bodies playing in front of you. Frequency response is a fundamental of good sound reproduction.

Loudspeakers have improved dramatically in the last 20 years. Have we reached engineering limits, or are advancements still possible?

I do not think we are even close to the limit—we still have to make a loudspeaker with a single transducer, no crossover, perfect dispersion, frequency response from 10Hz to 100kHz, negligible distortion, 120dB sensitivity, easy load on the amps, etc.

What role does in-room listening play in the design process?

Most of our speakers’ designs are based on in-room measurements and listening. Quite little is done on the computer, even on crossovers. We used to run simulations in the past, but now we do not do that anymore, since we know our drivers’ characteristics quite well and decided to use (relatively simple) first-order filters only, as they definitely sound better to our ears (and eyes because we value 3D reproduction as one of the main design parameters). It is a matter of testing a few different values of capacitors, inductors, and resistors, and the crossover design is decided fully by listening to different versions to decide what we prefer.

What are the engineering challenges confronting loudspeaker designers, and do you expect any breakthroughs in the near future?

I think there are two main fields where we can realize improvements. One is the research on new magnetic materials, and the other is the design of wider frequency-range transducers. These two together might lead us to the goal of the single-transducer, no-crossover, very-high-efficiency design. And by very high efficiency I mean a loudspeaker that produces 120dB sound-pressure levels when driven by one watt.

Alfred Vassilkov

Estelon

Alfred Vassilkov’s journey toward becoming Estelon’s co-founder and Chief Designer & Engineer began in his youth, amidst the backdrop of the Soviet era. Fascinated by sound, he tinkered with radios, enhancing their components to optimize sound quality. His passion led him to study electro-acoustics at St. Petersburg University, laying the groundwork for his future endeavors.

In 2010, over a leisurely Sunday breakfast with his family, Alfred realized his lifelong dream of creating the world’s finest loudspeaker brand, Estelon. Instead of pitching his idea to a corporation, he chose to establish his own company with his daughters Alissa and Kristiina by his side. With over 35 years of speaker design experience, Alfred’s pursuit of perfection and his ability to surmount challenges enabled him to develop groundbreaking technologies and unique materials. Inspired by Estonia’s lush nature, his designs strike a harmonious balance between engineering and aesthetics. Today, Alfred’s creations grace the homes of renowned innovators and leaders worldwide, a testament to his unwavering commitment to excellence in sound.

Do you consider loudspeaker design more of an art or a science?

For me, loudspeaker design is a blend of science and art. Science helps understanding how the sound works and guides me in choosing materials and components. But art also plays a role, making sure the design is simple and elegant.

Good loudspeaker design is all about keeping things simple. Just as in art, where the best pieces often come from simple arrangements, simplicity is key. We want our speakers to sound great but also to look good and be easy to use.

In the case of Estelon loudspeakers, my design ethos is deeply rooted in engineering principles. We meticulously place driver components within the cabinet to optimize acoustic performance. For instance, positioning the woofer towards the lower part of the cabinet facilitates acoustic coupling with the floor, necessitating a larger cabinet volume at the bottom. Meanwhile, the mid/woofer and tweeter are strategically positioned higher to minimize early reflections from the floor. Additionally, the Estelon cabinets feature soft, non-angled surfaces to achieve ideal dispersion characteristics, while non-parallel internal chambers help eliminate resonances. When these elements are combined and you “connect the dots,” the Estelon design emerges.

So, when asked if loudspeaker design is more science or art, it’s really both. Science gives us the basics, and art adds style and character. We design speakers that are technically impressive and appealing to the eye and ear. In the end, it’s about blending smart thinking with creative ideas. That’s what makes great speakers stand out and makes people want to listen.

What are the most important sonic qualities you strive for in your designs?

In my loudspeaker designs, I aim for a balanced approach that considers various sonic qualities crucial for a rich listening experience. Rather than focusing on just one aspect, I prioritize several elements to create speakers that excel in real-world settings like living rooms. At Estelon, our motto is that “every mm (or inch) matters!”

I value clarity and purity of sound, achieved by carefully shaping the speaker to minimize distortions and optimize sound reproduction. Additionally, I pay attention to dispersion, ensuring that sound is evenly distributed throughout the listening area for a more immersive experience.

Estelon designs also prioritize creating a lifelike 3-D audio picture, enhancing the realism of the soundstage. We believe this contributes to the emotional impact of music, making it feel more dynamic and engaging. Ultimately, our goal is to design and produce speakers that strike a balance across these sonic qualities such as clarity, purity, dispersion, and emotional resonance, in order to deliver exceptional musicality and transcend the typical audio listening experience.

What role does in-room listening play in the design process?

When designing Estelon speakers, I focus on making them perform well in everyday listening spaces, considering factors like room layout and materials. Unlike in perfectly treated rooms, we want our speakers to excel in typical living rooms, too.

To achieve this, we strategically position the components of our speakers to optimize their performance. For instance, as mentioned above, placing the woofer at the lower part of the cabinet not only enhances bass coupling but also facilitates seamless integration into various room setups. The mid/woofer is placed on the top to eliminate the early reflections from the floor, and so on. The whole design philosophy is based on many decisions that take into consideration the acoustical environment.

The Estelon speakers maintain a stable and realistic soundstage in any room. This means listeners can enjoy consistent sound quality, no matter the room’s layout. Overall, my goal is to create speakers that sound great and adapt well to the diverse conditions of everyday living spaces.

Loudspeakers have improved dramatically in the last 20 years. Have we reached engineering limits, or are advancements still possible?

From an engineer’s point of view, there are endless possibilities. While we may not experience revolutionary breakthroughs on a regular basis, the realm of possibilities remains vast. We have made significant strides in loudspeaker technology over the past two decades, but there’s still ample room for improvement. New materials, innovative design concepts, and cutting-edge manufacturing techniques present new opportunities for further refinement and enhancement.

As long as there is a collective passion for elevating the quality of sound reproduction, there will be progress and development. We may not experience huge leaps on a regular basis, but the journey towards perfection is an ongoing one, and at Estelon we love pushing the boundaries of what is achievable in audio technology.

What are the engineering challenges confronting loudspeaker designers, and do you expect any breakthroughs in the near future?

I believe that the selection of components plays a pivotal role in shaping speaker designs. From the materials used in cabinets to the crossover components and connectors, each element contributes to the overall sonic performance in its own unique way. As such, any advancements in these areas hold the potential to significantly impact loudspeaker design.

Looking ahead, I anticipate that breakthroughs in materials science and technology will pave the way for exciting advancements in loudspeaker design. Innovations in cabinet materials, such as the development of lightweight yet rigid composites, could lead to speakers that offer enhanced structural integrity and improved acoustic performance. Similarly, advancements in crossover components technology, such as the utilization of high-quality capacitors and inductors, have the potential to further refine the clarity and accuracy of sound reproduction.

I am optimistic about the prospects for breakthroughs in the near future. I believe that we can further expand the limits of what is possible in loudspeaker design.