How Sweet It Is

Muraudio Domain Omni ESL Omnidirectional Electrostatic Speaker

Audiophiles have long been enamored with the lifelike presentation of electrostatic speakers but vexed with having to sit precisely in the sweet spot to enjoy the glorious sound. Canada’s Muraudio aims to change that with the “world’s first omnidirectional electrostatic speaker,” the Domain Omni ESL, perfected over more than a decade by company founder and chief technology officer, Murray Harman.

S&V: Why did you decide to build an omnidirectional electrostatic speaker?
Murray Harman: I’ve been designing loudspeakers and amplifiers since the age of 10. About 12 years ago I heard a high-end omnidirectional design and was impressed with its open, airy, and lifelike sound. An omnidirectional loudspeaker can recreate the live musical experience in a way that no traditional forward radiating design can. At the same time, the pure and unparalleled clarity of electrostatic loudspeakers has been recognized by many as the ideal way to recreate sound. Yet much of the current flat-panel hybrid ESL technology has significant limitations—lower sound-pressure levels, a high degree of directionality, and poorly integrated bass response. I set out to combine ESL technology with an omnidirectional design while working to eliminate the traditional problems that ESLs have been known for. About two years ago our work culminated in the technology now incorporated in the Domain Omni ESL.

S&V: Tell us about the patented continuous curve electrostatic panel. How is it unique?
MH: Before Muraudio, compound curvature had never been patented as a viable ESL technology. Electrostatic loudspeakers are by design very directional, especially at higher frequencies. Flat or slightly curved designs on the market today may present beautiful immersive sound but require the listener to be in the “sweet spot” and will never image correctly from multiple listening points. These formats literally produce a wash of sound as large as the ESL panel creating it.

The design and manufacture of a 360 degree horizontally and vertically formed ESL panel is the basis of Muraudio’s patents. Our ESL panel creates a 360 degree sound field in the horizontal direction as well as perfect distribution in the vertical direction. This allows listeners to hear the section of the speaker that directly faces them whether they are in the traditional sweet spot or in a different location in the listening room. Because the sections are curved, your mind perceives a focal point just behind the speaker. The magic is that this focal point follows you as you move around the room.

S&V: The bass section uses three woofers mounted in a “force-neutral tri-axial configuration.” What does that mean and what are its sonic implications?
MH: The drivers are spaced at 120 degree intervals, mounted in a cast-aluminum sealed enclosure with a quarter-inch-thick walls. Motor forces from the drivers push directly against each other instead of being directed into the cabinet. This driver symmetry results in no net vibration to the cabinet, floor, or into the ESL panel assembly above. Add to that the incredibly stiff and smoothly curved aluminum casting with internal damping and the acoustic suspension system becomes inert without having to be unusually heavy. The aluminum cone driver moves so uniformly that modal resonances are inaudible, delivering linearity at maximum excursion with low motional loss. Over 10 kg of magnet structure provides the necessary motor force needed for deep bass extension, achieving F(–3) = 30 Hz (anechoic) in a sealed enclosure, while a spatially symmetric magnetic field reduces harmonic distortion. This means you experience accurate bass reproduction at all volume levels.

S&V: Powered (DA1, $67,000) and non-powered (PX1, $58,000) models are available. Why two versions? Tell us about each.
MH: With so many top quality analog and digital audio products in today’s market, we wanted to give customers a choice. The fully passive Domain Omni PX1 is designed to be externally powered using the customer’s preferred amplifier configuration, and supports bi-wiring and bi-amplification. The fully active Domain Omni DA1 incorporates a pair of Class D amplifiers (350 Watts RMS each) in a bi-amplified configuration independently powering the ESL and low-frequency driver array, and accepts either line level balanced analog XLR, or AES digital input directly from a preamplifier. Each version is identical in external design and sound reproduction capabilities.

S&V: What type of crossover is used to integrate the two sections in each version?
MH: Both models are two-way systems utilizing a single 4th order Linkwitz-Riley high- and low-pass filter crossing over at 450 Hz. In the passive PX1, the audio signal is separated using an analog crossover circuit utilizing the highest quality components, including air-core inductors and polypropylene film capacitors. In the active DA1, a 24-bit Digital Signal Processor provides the same crossover point.

S&V: Talk about the speaker's physical design, materials used, and finish.
MH: The Domain Omni ESL is all aluminum. The electrostatic cell is assembled using three 120-degree stator panels, each with 50,000 individually formed holes. These panels are mounted in a rigid frame with carefully engineered internal bracing and damping to eliminate all mechanical and film resonances.

A single piece aluminum cast is used for the bass enclosure, providing a complex shape that creates an intriguing design while minimizing dispersion of resonances. The high stiffness of the cast base and force neutral woofer configuration reduces cabinet vibrations to an imperceptible level. The electrostatic panel assembly is also force neutral by design making it possible to mechanically cancel vibrations that would otherwise be coupled to the membrane itself as with other single panel ESL designs.

Each Domain Omni ESL is custom finished over several days. It takes at least 18 layers of primer, paint, and protective coatings along with hand polishing to create an elegant and stunning look that is superior to even luxury automobile finishes.

S&V: How would you describe the Omni ESL’s sound? What sets it apart from other speakers in its price class?
MH: They produce the incredible precision and detail electrostatic speakers are famous for without requiring you to sit in one central location. Imaging is precise, coherent, and lifelike. The speakers disappear and what you hear sounds like an accurate reproduction of the original performance.

S&V: Feel free to highlight any other distinguishing attributes of the Omni ESL, especially qualities and features that justify its price.
MH: Over a decade of research has gone into bringing this unique patented technology to market. We are proud to say that each Domain Omni is “Handmade in Canada”, manufactured at our state-of-the-art facility in Ottawa, Ontario. A complex product to build, there are hundreds of individual parts that make up each Domain Omni ESL. Every loudspeaker we produce is measured in our own anechoic chamber to ensure a perfect result every time. Muraudio’s “Sound is Everywhere” approach provides both an individual and social audio experience where everyone enjoys pure, authentic sound reproduction. It’s like there is a sweet spot for every listener in the room. —Bob Ankosko