First major innovation in audio speakers in nearly 80 years!
Audio Pixels is an exciting enterprise that has developed a revolutionary technological platform for reproducing sound, thus enabling the production of an entirely new generation of speakers that will exceed the performance specifications and design demands of the world's top consumer electronics manufacturers.
Our patented technologies (principle patents in national phase in 13 countries), employ entirely new techniques to generate sound waves using low cost micro-electromechanical structures (MEMS). This innovation enables the production of speaker products that deliver performance that is many orders of magnitude better than conventional speaker technologies, all in an affordable package that is roughly only one millimeter thick!
Audio Pixels is the first and only known company that has successfully implemented the promise of Digital Sound Reconstruction (DSR) in a commercially feasible manner enabling a market evolution in a similar fashion to what has occurred in the transition from large, heavy, bulky analog CRT monitors, to the digital flat panel displays of today.
Effective business model
Audio Pixels will produce and sell a single type of chip that can be used either as a standalone speaker or cascaded in any multiples of up to 64 units of the same chip. The number of chips used in any given application is determined by the manufacturer’s desired audio specifications, based on their target end-application and target market. For example a single chip would more than suffice for a mobile phone, while a manufacturer may choose to use between 2-6 chips for a television application. This modular paradigm is entirely unique to the audio industry, which today expends significant resources designing and specifying new drivers, acoustic chambers and drive electronics for each new device. Audio Pixels innovative approach not only facilitates maximum flexibility to its customers, it further enables the Company to calibrate on the design and production on a singular product model, maximizing economies of scale, while limiting overhead associated with multiple versions of products.
Pent up demand for innovation in audio speakers
Driving the rationale for change and investment in audio speakers is the ever-increasing demand for smaller, thinner, clearer sounding, more power-efficient speakers. The key challenge is that for the most part conventional speaker technologies remain deeply rooted in the original voice coil inventions of Alexander Graham Bell. The inherent limitations of such speakers prohibit the delivery of quality sound in smaller packages. Audio Pixels innovation changes this paradigm.
Direct and indirect market research overwhelmingly suggest that both manufacturers and consumers alike are starving for real innovation in audio speakers. The main reasons behind the demand are:
- Form Factor: “Thin-is-in”; consumer preference is clearly toward esthetically pleasing devices that are thinner, smaller, lighter, and esthetically pleasing. While the industry at large has been able to shrink form factors of all other electronic devices, the last remaining barrier continues to be speakers which remain large, bulky, heavy, and extremely restrictive.
Audio Pixels speakers’ shatter the barriers of sound, by providing a speaker chip that is a fraction of the size, thickness and weight of conventional speakers.
- Complexity: the digital revolution has been forced to take a detour when it comes to audio speakers. Device designer’s are forced to bridge between the digital world of content and electronics, and the analog world of the speaker. Device design is severely restricted when it comes to the nebulous world of sound reproduction through speakers; a domain dominated by “sound gurus” and “golden ears” that iteratively fine tune dozens of parameters using their auditory senses rather than measured scientific methodologies. This translates into a highly restrictive design process that is long and expensive as it is complex.
Audio Pixels introduces to the speaker world the de-facto standard digital component paradigm, whereby device designers address their speaker needs based on predicable component specifications.
- Power Consumption: power consumption requirements are increasingly stringent in particular for embedded systems and automotive applications. The world’s ever increasing reliance on battery operated devices combined with growing environmental concerns are driving consumer and industries toward greener more power efficient devices. Conventional analog speaker drivers are perhaps the most inefficient transducer around, converting on average only 1% of their electrical energy into acoustic energy.
Audio Pixels speakers are over 10 times more power efficient without compromising quality, or increasing complexity or cost; thereby delivering tangible solutions to serious problems, while presenting new opportunities.
- Quality: There is an unquestionable market need for speakers that are not only far more compliant with current design trends, but that are also capable of producing high quality sound. Over the years, consumers of standalone speakers have habitually proven a willingness to pay a premium for higher fidelity sound, the same buying pattern should hold true for the endless stream of devices in which sound plays a vital role. Existing speaker technologies face manufacturers with an impossible challenge, as every attempt to shrink existing speaker technologies as to enable slim, sleek designs comes at the direct expense of the quality sound output.
Audio Pixels speakers’ offers performance that is incomparable when compared to existing speaker technologies of similar size, thus for the first time, permitting manufacturers and consumers alike to benefit from choice form factors without comprising the sound quality.
What is an Audio Pixels speaker?
An Audio Pixels speaker is a MEMS chip roughly 1mm thick. The chip replaces conventional speaker driver(s), enclosure or acoustic chamber, as well as the electronic circuitry associated with converting the digital signal feed to analog (via a D2A + Power Amplifier).
The Audio Pixels speaker chip is not only radically smaller; it consumes a fraction of the power, to produce far better acoustic performance (clear sounding, less distorted, more accurate sound reproduction). The qualitative differences are reflected in better performance in a substantially smaller package:
• Wider frequency range
• Lower frequencies
• Immeasurable distortion
• Louder sound volume
• Less power consumption
Audio Pixels speakers also offer unprecedented flexibility. In sharp contrast to conventional speaker technologies where the types and number of drivers, as well as the enclosure and its electronics all must be customized and endlessly fine-tuned to a specific application; Audio Pixels offers a single chip design that is modular and perfectly predicable and linear. Given that the total number of “pixels” is the only factor determining quality, frequency and sound volume, manufacturers and device designers need only to determine the target acoustic performance and select the appropriate number of speaker chips, which are serialized using a single controller.
The homogeneous construction of the chips simplifies and reduces the cost of customer design, integration, assembly and product inventory. It also permits the Company to optimize its pixels, the array, the fabrication and test processes.
The loudspeaker is the most variable element in an audio system responsible for most audible differences. First patented by Alexander Graham Bell as part of his telephone in 1876, the speaker, over the years has gone through a series of improvements most notably by Ernst Siemens in 1878; to the modern version of the moving coil principle invented by Chester W. Rice and Edward W. Kellog in 1924. Since, improvements in the audible performance of speakers have mostly resided in cabinet designs, acoustic suspension, materials, higher temperature adhesives, permanent magnets, precision manufacturing and so on; yet the very same fundamental principles invented some eighty years ago are still in use today!
In order to understand the breakthrough of Audio Pixels technology it is important to pinpoint various mechanical and acoustic principles as they pertain to conventional, alternative, and the Audio Pixels speaker technology.
A loudspeaker or speaker, is essentially an electromechanical transducer which servers to convert an electrical signal into sound (pressure waves) by moving variable volumes of air (displacement) at variable speeds. Beyond the fact that conventional speaker design did not account for today’s hi-fidelity digital sound, the fundamental limitations of conventional speaker technology is that they attempt to balance a variety of contradictory requirements needed for producing sound from an electrical signal. "Impedance matching", a term which refers to the ability of one system to efficiently convert energy from one form (electrical) to another (acoustical) is perhaps the’ most critical factor preventing conventional speaker technologies from achieving superior sound, especially when applied to smaller speakers and/or with reduced available power.
Principally conventional speakers need to move a single membrane. The membrane should be very compliant, reproducing the input signal accurately. Depending on the input signal appropriate membrane movement needs to be both large and small and both fast and slow. To effectively do so, a speaker membrane should be both large and small, and both light and heavy. These opposite requirements are inherent in the design of conventional speakers. Finding the right tradeoffs is as much an art as it is a science. Further the associated speaker construction, circuitry and acoustic chamber / enclosure must also be able to support and administer such opposing requirements.
In conventional speakers, the impedances of the membrane and the air are very different. The impedance mismatch of conventional speaker designs manifests itself (among others) in energy loss, limited volume and limited frequency ranges. Conventional speaker technologies force manufacturers into a complex series of compromises, none of which work in favor of today’s consumer electronics, as conventional speaker technologies do not scale down well at all, into smaller, lighter, less power consuming speakers without experiencing significant reduction performance and capabilities.
At the heart of Audio Pixels technology is an innovative high impedance structure based on a high-efficiency driving mechanism which is capable of producing remarkably high air pressure despite its diminutive size. Audio Pixels revolutionary structure can produce on average roughly 10 times the pressure of a conventional speaker of the same surface area, amplitude and frequency.
The acoustic principles in applying our structures to produce sound is known as “Digital Sound Reconstruction” (DSR) which principally generates the desired sound waves by using arrays of pressure generating drivers. The principles theories of DSR while envisioned decades ago had yet to be realized as a viable speaker solution. It is the clever combination of advanced fluid manipulation techniques, miniaturization technologies and the breakthrough driving mechanism of Audio Pixels that has enabled the many advantages of DSR to be realized in commercially viable manner. The end result is a speaker that literally blows away competing technologies.
a. Excellent impedance matching. Maximizes energy conversion (from electrical to acoustic). The theoretical efficiency limit of Audio Pixel speaker is 60%; which is roughly 60 times better than conventional speakers. The improved impedance matching also serves to significantly increase the SPL (Sound Pressure Level), or loudness, achievable from an Audio Pixels speaker when compared to conventional speakers of similar dimensions.
b. True digital reproduction of sound using a large array of identical micro-speakers. Unlike conventional speakers in which the membrane is required to compliantly travel varying distances and speeds all the micro-speakers are required to perform the exact same simple function, i.e. work or don’t work at any given time. When working, they travel at the same speed over the same displacement.
c. DSR offers performances that are orders of magnitude better than conventional speakers of similar sizes. The frequency range can be much broader and the frequency response perfectly flat. The distortion level is a fraction of that of conventional speakers, in most cases, well below the human detection threshold.
d. Low Power Requirement – the driving mechanism uses a tiny fraction of the power required by conventional speakers resembling the power requirements of headphones.
e. Design flexibility – not only are the speaker “drivers” very thin, they require no cabinet or enclosure and therefore can be mounted on most any surface (including SMD configurations), providing device designers with unprecedented flexibility.
Principle of Operation
The sound pressure generated by an Audio Pixels speaker is proportional to the number of operating micro-speakers (“Audio Pixels”) and the throughput of each one. Varying the number of pulses over time produces different frequencies. Unlike analog speakers, individual micro-speakers operate in a non-linear region to maximize dynamic range while still being able to produce low frequency sounds. The net linearity of the array comes from linearity of the acoustic wave equation and uniformity between individual speakers. The overall non-linear components in the generated sound wave have a direct relation to the number of micro-speakers in the device.
Additional Advantages over Conventional Speakers
Damping: Conventional speakers oscillate long after the input signal is stopped. The heavy membrane transfers only a fraction of its energy into the air and it continues to oscillate for a considerable time before the oscillations decays. Conventional speaker systems utilize artificial damping to overcome this problem. The most common damping mechanism leverages the amplifier to absorb large opposite currents induced in the voice coil of the speaker due to its movement. The excess currents require sophisticated amplifier designs. In contrast, an Audio Pixels speaker "stops on a dime". The signal is initiated and terminated within one clock cycle.
Vibrations: Due to the high impedance matching of Audio Pixels speakers, a much smaller movement is required to generate the same loudness. According to Newton's law, each action generates an opposite reaction. In a speaker, movement of the membrane generates opposite movement of the frame. The smaller movement of an Audio Pixels speaker generates significantly lower vibration levels. Vibrations are often problematic in sensitive electronics. In displays for example, excess vibrations produced by speakers can cause deformation of the image and potentially damage the display elements. Vibrations are also problematic in full duplex communication devices (such as mobile phones or blue-tooth headsets), where the microphone can pick up the speaker vibrations generating echo and feedback noise. The reduced vibrations of an Audio Pixels speaker allow much more moderate levels of echo reduction and suppression.
Directivity Control: Audio Pixels invented (and patented) a scheme of controlling the acoustic directivity pattern of its speakers. The scheme is similar in nature to other phase-array devices, most well known are radars and RF antennas. The same speaker can be used as an omni-directional sound source (much like conventional speakers), or a unidirectional source (a narrow beam of sound is projected in one directions, and almost no sound is projected in any other direction), or a multi-directional source projecting several sound beams (each may carry different audio), in several different directions. The applications leveraging control of sound directionality are limitless.