HDMI is now the mainstream interface for entertainment products available on the market. Some users may have multiple sources that need to be connected to one monitor or one input source that needs to switch between multiple monitors. For example, a laptop is connected to four monitors with HDMI. The user wants to be able to support multiple displays, 4K definition, plug-and-play, audio synchronization, and others. The HDMI splitter was invented to solve such problems. When there are issues with these audio-visual electronic products, it will inevitably lead to negative reviews and a reduction in sales.

Issues and Solutions for HDMI Splitter Image Quality

Although the HDMI splitter can output multiple signals to different devices simultaneously, many issues can occur when you want to achieve this. For example, some poorly designed models could have poor image quality due to signal attenuation or noise interference. Sometimes when TVs, projectors, and LCD monitors are all connected, the EDID fails to be recognized so there is no video signal output, which leads to customer complaints. From our testing, we found many poorly designed HDMI splitters. A past client had an issue where the input is a 2K signal and the outputs are connected to 1080P and 2K monitors, the original 2K monitor will only show 1080P. Only when the 1080P monitor is unplugged, the 2K monitor can display normally. This can cause great inconvenience for the user.

After Allion’s consulting team analyzed this issue, we assisted the client by recommending that the input and output terminals read EDID separately and output the highest resolution instead of outputting the 1080P signals simultaneously. If the input terminal is a 2K signal and the output is connected to a 2K screen, it should output a 2K resolution. This way manufacturers can effectively avoid customer complaints in the future.

* EDID: Extended Display Identification Data, a display information standard developed by VESA used to describe resolution, color gamut, and other information

Faster, Easier, Better: The Most Trusted HDMI Product Testing Consultant

Allion is an official certification laboratory authorized by the HDMI Forum. We have a complete range of HDMI testing equipment that can ensure compatibility amongst different kinds of HDMI products, helping you with your quality control along the way. Allion can also provide clients with fast and accurate evaluations that effectively shorten schedules for certifications. With plenty of experience, Allion provides the best consulting services for our clients and helps them eliminate issues they may encounter. This ultimately reduces the possibility of users returning their purchased products.

  • A Comprehensive HDMI Compliance Test Solution: Passing certification tests can ensure signal transmission quality. It also allows manufacturers to avoid being audited by the HDMI Association
  • Customized Testing and Consulting Services: HDMI monitors with repeaters were designed because of market demands. HDMI certification alone cannot guarantee the quality of your products. Allion can help clients conduct and pass compatibility tests, user scenario simulations, and more, ensuring these products are compatible with one another.


With our rich testing experience and collection of testing equipment, we can provide clients with fast and accurate certification planning that effectively shortens the certification schedule and helps clients quickly obtain HDMI certification. Allion is an official certification laboratory authorized by the HDMI Forum. We also have a complete range of HDMI testing equipment that can ensure compatibility amongst different kinds of HDMI products, helping you with your quality control along the way.

  • Quickly provide product development certification strategies with rich testing experience and collection of testing equipment
  • Quickly obtain logo certification (HDMI)


Allion has a complete range of HDMI hardware certification testing equipment and testing environments. With our testing solutions, we can ensure each client’s certification process is qualitative, quantitative, and reproducible. Through Allion’s service, we can assist our clients in obtaining accurate test results easily, ensuring the quality and performance of their products.

  • Provides more accurate results
  • Provides professional issue isolation and debugging support for our clients to make products


Not only does Allion have professional teams with decades of experience, but we also know how to design quantitative tests and user scenario simulations, allowing our clients to comply with requirements and user expectations. Allion’s professional teams can also provide suggestions for product modifications, assist with supplier management, and help with specifications requirements from international associations during product development. This further enhances the quality of our client’s products, ensuring high standards that comply with international specification requirements.

  • Provides a better and more complete experience for brands to establish ODM ecosystem plans
  • Provides more complete user scenario testing solutions


If you have any requirements or questions, please contact us.