The SKYWORTH W92 88-inch high-end 8K OLED TV is the world's first glass sound TV, featuring the first ever audio system to adopt electromagnetic drivers that vibrate a flat glass diaphragm to produce sounds. To achieve this, the glass diaphragm with dimensions of 1950mm x 150mm x 0.7mm were placed underneath the TV screen, creating a cohesive and minimum design across the appearance of the TV and audio system. The large-area diaphragm vibrates forward as a whole and forms plane air waves, which outperform diverging waves produced by individual spherical points, according to acoustic principles. Theoretically speaking, that can avoid the loss of sound pressure as sound travels farther, maintaining a consistent sound quality. (The effective distance to maintain sound quality is subjected to the area of the sound wave surface).
The SKYWORTH W92 is the world’s first flat-diaphragm sound device, and the first ever to be applied to a TV product. With no practical examples to reference, the development process was based on theoretical guidance and hard work.
1. Theoretical guidance and support
Firstly, our designer analyzed three factors that supported the feasibility of the project based on the theoretical guidance in the demonstration stage:
1) The diaphragm area of this project can reach twice the area of 18-inch bass vibration. The large vibration area can bring sufficient sound pressure and sufficient low-frequency dive.
2) The elastic support system provides sufficient stroke and compliance to expand the bass effect.
3) By reducing the thickness of the vibrating plate (glass) to reduce the quality of the vibrating plate, the sound pressure can be increased. At the same time, local deflection and split vibration can be generated during high-frequency vibration, which can derive high-pitched components.
Despite the theoretical guidance, the team faced several challenges developing the product with no references to guide the process.
2. Disputes over technical solutions
With no previous experience, the team were initially skeptical about the feasibility of the electro-acoustic solution. Fortunately, our leaders at all levels in the R&D department provided positive encouragement and operational support. Under the coordination of leadership, colleagues from all departments worked together to conduct a preliminary demonstration of the glass-acoustic solution – The technical planning department helped coordinate glass, while the ID structure department arranged the proofing of sounding the device’s frame rapidly.
The electro-acoustic business line quickly carried out the performance test and subjective evaluation on the prototype of the sounding device. It was agreed that the solution was feasible, and the performance was excellent. However, there were issues discovered including scarcity of glass resources, processing difficulties, mechanical vibration, reliability of long-term use of the elastic support bonding process and unobvious separation of stereo channel. Continuous study was required to identify solutions during the project. In October, a trial production verification was initiated under the arrangements of the company leader, which brought the verification to a complete conclusion.
It was only the first step of the project after the scheme was passed. In response to the issues identified during the demonstration stage, the team continued to collaborate and showcased perfect and efficient collaboration spirit and professionalism:
1. Glass resources: coordinated multi-resources including glass factories, cutting factories, and printing factories. As it was required to get the glass in a extra-long size, traditional local glass manufacturers were unable to meet the requirements. Eventually, the technical planning department contacted a renowned US company for collaborative research. Diagonal cutting techniques were applied to meet the standard of samples. Each 1900*1500 piece of glass can only produce two pieces of sounding glass. In order to pursue the maximum sound pressure level and the widest frequency, as well as reducing distortion, various thickness sizes such as 0.5mm, 0.7mm, 1.0mm were verified respectively to find the perfect balance between sound pressure level and frequency response.
2. Reliability verification: The project team purchased equipment at all costs -- arranged more than ten sets of frame equipment, assembled the sound devices for the acoustic verification test and carried out the high and low temperature life expectancy experiment of the glass bonding process.
3. Solution of mechanical vibration: After over ten structural and process optimizations, the structural and electroacoustic engineers tackled the abnormal sound phenomenon such as high-volume glass resonance, frame resonance and device resonance.
4. Multi-channel panoramic sound reconstruction: Electroacoustics and software engineers worked with Dolby FAE for solutions 2.1, 3.1 and 2.1.2 through a variety of trials and applications such as power amplifier, DAP and ini configuration. After more than two months of fine adjustment and multiple comparison auditions by the Golden Ears team, the perfect panoramic sound reconstruction and sound quality was achieved through repeated optimization.
Integrating sound and video -- the inevitable achieved by chance: the realization of integrating sound and video began with a random question. The EVT prototype was displayed in an internal technology showcase where the product’s hidden defects were discovered by chance (the TV was placed on a lower set and showed a lower sound image position at that time). SKYWORTH would not be vague about possible flaws. To combat this, the electroacoustic team formed an organized structure, ID and hardware to put forward a professional demonstration and promptly proposed a remedial plan by applying Air Motion Transfomer to raise the focus of the sound image, which eventually accomplished the perfection of integrating sound and image.
5. “Move around the venue”: As 88W92 is relatively large in size, it can’t fit in the elevator of our technology team’s building. There was no professional venue for resolution, audio quality testing and subjective evaluation. Our project leaders coordinated with the quality department to clear a space in the office to support project debugging. The pilot line also provided a large office space for the EVT prototype assembly, multiplexing and tuning. Our team and other departments had the chance to witness the process of product development and how we brought it into real life, experiencing both the sadness and joy.
It took eight months from ID to program verification, experimental verification and trial production to verification. With the endless efforts from the project team, support and coordination from several units and partners, this project has achieved a breakthrough in innovative, going beyond the industry’s leading standard.
It demonstrates the strong teamwork of the company, commitment to innovation, and the perseverance and professionalism of team members.