oneZ background

In philosophy, science, and the arts a call often goes out to simplify. In ever more complex times the aesthetic allure of an elegantly simplified philosophy, theorem, or design is alluring. In the disciplines of product design and engineering an aesthetic of simplicity also brings the possibilities of lowering costs while increasing reliability and performance if a simpler solution to a design requirement can be found.

It was this allure of the aesthetics of simplicity that led to the oneZ speaker design.

At the turn of the 21st century an underground revolution was well underway in the world of hi-fi music reproduction. Thanks to the Internet esoteric technologies previously hidden from view were being presented for all to see and consider. It was then I learned that one branch of ultra-fi "audio maniacs" (as they call themselves) in Japan were devoted to single driver wide range speakers. Further research revealed devotees of this seemingly impossibly retrograde technology worldwide. What were they up to why have they veered so far off the engineering mainstream?

Traditional hi-fi loudspeaker system design uses multiple drivers (woofers, midranges, and tweeters) optimized for limited frequency ranges. A crossover network filters the voltage analog of the musical performance output by the power amplifier into multiple bandwidth-limited signals that it directs to the multiple drivers for reproduction. It is the designers' desire that these multiple bandwidth limited signals will then recombine in the air between the speaker and the listener into a full bandwidth reproduction of the musical event. This design philosophy developed over many decades as a result of viewing the system from a frequency standpoint. Using drivers similar in size to the wavelengths they are to reproduce (small for tweeters, large for woofers) gives a wider distribution of the frequencies in the room and lower harmonic distortion due to the drivers acting more like stiff pistons. The multiple drivers and crossovers also gives the engineer a tremendous degree of control allowing parameters such as frequency response to be adjusted.

In contrast devotees of single driver wide range speakers tend to view the primary design problem not in frequency terms but rather in the time domain. Their thinking and experience is that the full range output of the audio amplifier is akin to Humpty Dumpty. That is once broken apart "all the King's horses and all the King's men" cannot put it back together again. Especially if something as imperfect as a voltage to acoustic transducer is in the chain. Thus a single highly developed speaker driver is asked to reproduce 8, 9, even all 10 octaves of the audible spectrum. Designing such a driver is a very tall order. However the reward is that it will act as a point source with naturally excellent time domain behavior. Additionally by eliminating the crossover filter and it's well documented signal distorting mechanisms the amplifier signal can be directly connected to the driver presenting all of the unfiltered wide band signal for the driver to work with.

In a now notorious cover story one of the major English language high-end audio magazines presented a high power transistor amplifier vs. a low power single ended triode amp under the headline "if one of these amps is right the other must be wrong". Some will take a similarly absolutist stand on the question of multi-way vs. single way loudspeakers, "if one is right the other must be wrong". In engineering and design I consider such rigid dogma a bit silly and shortsighted. In fields such as aircraft, automotive, and motorcycle design it is manifestly obvious that the size and complexity of the design will vary with the role it is to fill. In the enthusiast niche of, for example, sports cars some of us like small lightweight examples while others like nothing better than the massive torque of a big V-8 and gladly suffer the resulting weight penalty.

Thus I approached an investigation of single driver wide range speakers with an open mind from the engineering side, curiosity as to what the 'audio maniacs' were hearing, and a strong aesthetic allure to this elegantly simple form.