The Future of Audio Speakers and Sound
If you love sound and music, then you know that the quality of the speaker is one of the main factors that determine the quality of the sound. Speakers have not seem to change as much as other things in our lives, such as computers and cell phones, but are they unchanging? To find out, you can explore the latest patents awarded in the important area of sound speakers. Foreign inventors and foreign countries are the most common winners of patients, especially from Asian countries. This was not only true of utility patents, which cover improvements in speakers, but also for design patents, which cover the artistic designs of speaker cabinets.
A quick overview of waterproof speaker structure helps to see where the latest innovations are being made. The sound producing mechanism of speaker is held in place by a frame. The frame consists of: a basket, a soft donut shaped gasket, and two plates that carry the load of the magnet. There are seven components of this mechanism. These elements are: the magnet, the metal core, a voice coil wrapped around a light weight bobbin, the cone or diaphragm. The voice coil and cone/diaphragm are a unitary assembly and held in position by a speaker surround and the spider (also known as a damper). When current flows through the voice coil, it is pushed forward by electromagnetic force.
Out of the 27 utility patents in the past 18 months, the greatest number belong to the voice coil, which has 8. The component with the next most innovation is the cone (also called a diaphragm), which has 6. The third is the spider (also called a damper) with 4 innovations. Followed by these are the basket (2), magnet (2), gasket (1), horn (1), and surround (1). A patent was even issued for a new type of dust cap (1) that disperses pressure waves with less interference. The dominance of voice coil patents might just be evidence that this is the critical point because this is where electrical energy is converted into mechanical energy for the purpose of pushing air.
In addition to innovations that focused on components, there were 10 utility patents that involved major restructuring of the speaker. Examples of this include the use of bar magnets or voice coils embedded in the cone. In fact, the majority of innovations involving overall speaker structure were for flatter speakers. A massive research and engineering effort spent on creating flat speakers was a clear other trend in the past 18 months. This all points to one thing: the speaker of the future is going to be flat. At least that is what the manufacturers think. This is likely to be based on market research that shows customers vying for flat speakers to go along with their flat panel TVs.
An example of an innovation in flat speakers comes from a patent by Sony. This design produces a speaker that can be 5 ft tall, 3 ft wide, and where the sound is generated by vibration motors that push a non porous fabric. There is no voice coil and no cone. The Sony patent includes the uses of rack and pinion gears to adjust the location of the vibration on the fabric for optimal sound. We all want our flat panel TVs, and in the future, we may all want our flat panel speakers, too.
Freelance inventing is not dead. The two clear leaders in speaker innovation are freelance inventors and the Pioneer Company (Table 1). Combined, these two make up 41% of all new utility patents in the past 18 months. Following these two leaders are Sony, Matsushita, and the collaboration of Pioneer Co. and Honda Co., in order of the number of patents. These latter companies make up 26% of all new utility patents. All of the patents were awarded to for profit entities except one lone patent awarded to National Taiwan University.
Design patents are mostly for look of speaker cabinets, giving the inventor rights to a certain type of the speaker appearances. Standard speaker cabinet designs had a clear lead over the other types with a frequency of 9 patents in the 12 months. The other types of design patents are for home theatre cabinets, automobile speakers, remote acoustic hailing devices, iPod docking stations, and of course, computer speakers. Other types include: microphone shields, portable speakers, subwoofer enclosures, tweeter enclosures, and even speaker stands. The top five design types listed above account for 59% of the speaker designs.
Out of the patents that were just design patents, 57% were for just only 1 speaker; 57.1%. Designs with two speakers had 26.5% of the patents, with far fewer patents that involved more than two speakers. The design with the largest number of speakers had 8. This speaker was by Moog Inc. for a remote acoustic hailing device. These military devices are for delivering audible warning messages to potential threats at stand-off distances.
The leading companies in the speaker design patents were Sony in the top slot, followed by Samsung, SDI Technologies Inc., Moog Inc., Hosiden, and Panasonic. These six companies accounted for 69% of all the speaker patents in the past 12 months. Even though the two leaders are foreign, there were also three domestic companies in the top six for speaker design patents, which is nice to for American engineers to see.
One discouraging aspect of recent speaker patents for American engineers is the predominance of patents by foreign inventors over that of domestic inventors. The percentage of domestic utility patents for portable speakers was a measly 11%. Out of the 27 total patents that were reviewed, 24 of them were foreign, while only 3of them were domestic.
With regard to speaker design patents that focus on speaker enclosures, the story is similar, with 43% of speaker design patents going to domestic inventors. Although American inventors do not account for the majority of the patents in speaker design, it is clear that they are more interested in speaker design than in speaker function.
The electromagnetic speaker of today has had largely the same structure since it was patented in 1875 by Alexander Graham Bell. The trusty speaker may not have been the target of radical technical inventions for some time, but the newest patents awarded show that radical design and performance improvements may be in our future.
Nathaniel Lee Glenn is a technician at State of Franklin Analytics, member of the Audio Engineering Society, and engineering student at the University of Tennessee in Knoxville.