Electrostatic Reference Speakers




Model G-3
Model X-1
Model 2

Click on pictures to enlarge

The G-3 is the latest Beveridge speaker design. Although it incorporates the knowledge and creations of my father, it is 100% my own creation. Yes, it is a lot prettier than the original Model 3, but that is where the differences begin.

Up to this point, all Beveridge speakers were built by installing an acoustic lens into a cabinet. In some cases, like Models 1, 2, and 2SW, the cabinet was made using flat pieces of wood. Models 3, 5, and 6 were made using round tubes. In each of these, the lens had to be installed into an already existing structure.

The G series starts with a whole new concept. It is the lens itself which determines the size and shape of the speaker and gives its strength. Once the lenses are joined together with bulkheads and stringers, a thin skin of very flexible 1/8 inch plywood is joined directly to the structure of the lenses with a 3/4 inch thick bedding of Microspheres and Epoxy resin. This forms a structure which is extremely strong, rigid, and (conveniently) light. It also ensures a perfect fit of the lenses to the cabinet.

The original Model 3 was, and still is, one of the best speakers ever built. Nevertheless, some thought that it might be a better idea to separate the woofers from the main electrostat cabinet. Therefore, with the G-3, I have chosen to put each woofer into its own enclosure. There are also some other good reasons to separate the woofers from the electrostats. One of these is that it allows me to make the footprint of the electrostat much smaller. This results in a tall, slender speaker which presents a far less imposing presence in the room than any previous Beveridge speaker.

The most significant feature of the G-3 is the  new lens design. I watched as my father progressively altered the amplitude front of his speakers, starting with the almost perfectly uniform amplitude front of the original Model 2.

In an effort to achieve the highest possible SPL, as measured by a centered microphone, Bev increased the center amplitude "bloom" with each subsequent system model he designed. (In those days, high SPL was the holy grail of the entire audio industry.)

In the G-3, however, I have restored the amplitude front uniformity. This turns the entire room into a sweet spot, with no preference for any particular location. Realism, for which our systems are justly renowned, is further enhanced by this redesigned lens. As I have been very impressed and encouraged by the results of these modifications, all my future designs will incorporate them.

As is widely acknowledged, Beveridge Model 2SW was the first hybrid system to incorporate a dynamic sub-woofer of the infinite baffle design. With its limitations, the addition of the sub-woofer had nevertheless enabled the 2SW to gain an additional 10 dB SPL and, in due course, become our best selling model. The new G-3 system includes our newly developed woofer, which takes advantage of lessons learned over the intervening 30 or so years. Specifically, we have adopted a transmission line design, with inherently superior qualities over the enclosed baffle design.

Over a period of some eight months, my friend Arthur Vered and I have worked closely together, to the exclusion of all other work, to develop a truly superior woofer. This resulted in a superlative product, a 10' transmission line speaker, housed in a cabinet similar in shape to the electrostat. Apart from employing an expensive, aluminum-coned 10" driver of the highest quality, the shape of the woofer which eliminates any flat surfaces (save the back) also results in enhanced rigidity. Further, no particle board (MDF) is used in its construction, only the highest grade plywood, reinforced by Microspheres and Epoxy resin. The same technology is employed in many high stress environments, such as airplane and speedboat construction, where extreme rigidity and light weight are required.

The resulting woofer exceeds my highest hopes. It is so fast and natural and blends so well with the electrostats that a cello solo sounds just like it's in the room. Existing Model 2SW as well as Model 3 owners will notice a dramatic improvement in their systems if they replace the original sub-woofers with this woofer. For that matter, these woofers will improve the performance of any hybrid electrostat on the market today.

The new G-3 system can presently be heard at my factory in Santa Barbara California.


Model X-1

The Model One was the first pair of speakers my father made utilizing his invention of an acoustic lens.

Each speaker measured six feet tall by three feet wide by some two feet deep. It was a single source, full range, wide dispersion cylindrical wavefront, monopole electrostatic loudspeaker. It was also an active speaker with its own dedicated integral OTL tube amplifier, developed by my father. The design's frequency range is unknown, but I believe it could go well into the 20 Hz range.

They performed beautifully in the very difficult room at our home on Franceschi Rd., on the hilltop overlooking Santa Barbara. I believe that it was this room that caused my father to conceive the idea of a vertical, wide dispersion cylindrical wavefront as well as the concept of the acoustic lens necessary to accomplish such a wavefront. This room was about 60 feet long by 20 feet wide (ending in a small L-shaped extrusion). At each end there was a solid wall with no windows. What made this room so difficult to work with was the fact that along each of the long walls there was about 30-40 feet of floor-to-ceiling interlocking sliding glass doors. These glass walls were parallel to each other and had a polished concrete floor between them for most of their lengths. There were curtains, but they were almost always pulled back into the corners. Very few speaker systems, then or now, can work with such a difficult room, but the Model One handled it beautifully.

Akio Morita, the founder of SONY Corporation, spent almost a whole week at our house, along with a battery of his engineers, investigating the performance of these speakers. He was so impressed that he wanted to buy out the entire design and produce it under the SONY name. Yet my father still had ideas relating to the many advantages of this acoustic lens and its perfectly uniform cylindrical wavefront which he wanted to develop further. Since the offer from SONY would have precluded any further involvement by my father into the project, he turned down Mr. Morita's offer.

When we decided to go into production ourselves, we realized that the Model One was too large to be commercially acceptable by the domestic market at that time. With the aid of Donald McFarland, a noted interior designer, my father rescaled and redesigned the cabinet; the first production speaker became the well-known Model 2. The scaled down version preserved all the sonic qualities of the Model One, except for an unavoidable reduction in bass extension. The Model 2 became a success, launching Beveridge straight to the top of the audiophile market.

Today, honoring that unique Model One, I am resurrecting and introducing the design in its radically new, modern format - the X-1. Although its width and depth remain relatively the same, it gains almost two feet in height. The most striking difference between the X-1 and Model One is the doubling(!) of its electrostatic radiating area. This doubling of radiating surface allows for a 3 dB gain in headroom over its predecessor.

The Model X-1 is a complex design. The doubling of the transducer area doubles the capacitive load placed on the amplifiers. Each speaker will require over 3000 VA (the same power required by a pair of Model 2s). The acoustic lenses are modified to take advantage of this greater surface area. They also retain the 180-degree polar dispersion of the original. The frequency range of the X-1 goes more than an octave lower than the Model 2. This enables the X-1 to be the first single source, truly full range electrostatic speaker ever, covering the entire audio range from 20 Hz up to 18 KHz.

This impressive and imposing mammoth of a speaker will appeal to the very few, whose appreciation for the wide frequency range of this speaker will override all other considerations.


Model 2

It was our first production speaker. For information on its ancestor, the Model One, please click here.

The Beveridge Model 2 is a very unique loudspeaker and, in the opinion of many, the best speaker we have ever produced. It is a scaled down version of its predecessor the Model One, such that it can fit through doors and hallways.

It is an active speaker, driven by its integral OTL tube amplifier, capable of an equivalent output of 1500W. Its full range of 40 Hz - 15 KHz (+/- 2 dB, with useful output at 35 Hz) of 180 degrees cylindrical wave front is also referenced here. For more on cylindrical wavefront sound propagation, combined with the benefits of a monopole design, I suggest that you also visit JansZen.

The current Model 2 produced today has an entirely redesigned lens. This work was done by my brother Ross Beveridge of Colorado State University (computer department), employing his custom-developed software. These tools were totally unavailable to my father at the time. The net result of this development is, among others things, a smoother and more uniform amplitude front. In addition, the lens reinforcement is now accomplished, as it is in the Model G-3, by means of Microspheres and Epoxy resin.

The amplifier design and construction also benefits from 35 years of accumulated experience and technology improvements. High quality components are used throughout and modern manufacturing techniques are nowadays employed.

SPL, in and of itself, is not and never was the main objective in the design of the Model 2. In my opinion, the dynamic range of a speaker is of far greater importance. For dynamic range, the Model 2 is truly unsurpassed. It may not equal the G-3 in terms of total SPL, but it was, and it remains today, to be the only single source, full range, cylindrical wavefront, monopole, electrostatic, active loudspeaker system in the world.