HDS-404MV Overview and Use Cases

What Is the HDS-404MV?

The OREI HDS-404MV is a 4K@30Hz 4x4 HDMI seamless matrix with multiview and audio extraction. It allows up to four HDMI source devices to be connected and routed to up to four HDMI displays.

The HDS-404MV can work as a regular 4x4 HDMI matrix switch, where each output can select one HDMI input. It can also work as a multiviewer, allowing multiple HDMI inputs to appear together on one screen in layouts such as 2x2, left/right, up/down, one-big-three-small, and PIP.

The HDS-404MV supports HDMI 1.4, HDCP 1.4, video resolutions up to 4K@30Hz, with a video bandwidth of 10.2Gbps. It supports seamless switching, built-in scaling, power-off memory, PIP window location control, stereo 3.5mm audio output, Toslink Optical audio output, LPCM / AC3 / DTS audio formats, front-panel control, IR remote control, Micro USB control, and RS-232 control. 

The HDS-404MV is useful for security monitoring, control rooms, classrooms, conference rooms, retail displays, sports bars, multimedia rooms, and AV setups where multiple HDMI sources need to be switched or viewed together.

IMPORTANT — HDS-404MV Is a Matrix and Multiviewer

The HDS-404MV is not just a basic HDMI switch.

It supports two main functions:

This means the product can be used for standard HDMI switching or for viewing multiple HDMI sources on one screen.

IMPORTANT — HDS-404MV Supports 4K@30Hz, Not 4K@60Hz or 8K

The HDS-404MV supports video resolutions up to 4K@30Hz.

It does not support 4K@60Hz, 4K@120Hz, or 8K.

For 4K@60Hz systems, use an HDMI 2.0 multiviewer or matrix.

For 8K or 4K@120Hz systems, use an HDMI 2.1 device that supports the required bandwidth.

IMPORTANT — Multiview Mode Is Not the Same as a Video Wall

The HDS-404MV is a multiviewer, not a video wall controller.

Multiview mode combines multiple HDMI sources onto one display.

It does not split one image across multiple displays to create one large video wall.

Use this product when you want to view multiple HDMI sources on one screen.

Do not use this product if you need a 2x2 video wall where four TVs act like one large display.

IMPORTANT — Output A Is the Main Multiview Output

The manual describes the HDS-404MV as a 4x4 quad multiviewer with seamless matrix switching.

Output A is the main output used for multiview display modes.

Output B, Output C, and Output D can be used as normal switcher outputs. The COPY function can also copy the Output A display mode to Output B, Output C, and Output D at the same time.

This means if you want the same multiview layout on multiple displays, use the COPY function.

IMPORTANT — COPY Function Copies Output A to Output B/C/D

The COPY button copies the Output A display mode to Output B, Output C, and Output D.

This is useful when the user wants the same multiview layout shown on all connected displays.

If COPY is turned off, Output B, Output C, and Output D can be switched normally to show selected HDMI inputs.

IMPORTANT — Audio Output Has Format Limits

The HDS-404MV includes:

• 3.5mm stereo audio output 
• Toslink / S/PDIF digital audio output 

The manual lists supported audio formats as LPCM, AC3, and DTS.

If using the 3.5mm stereo output, set the source audio to a stereo-compatible format such as PCM / LPCM.

If using Toslink, make sure the connected soundbar, AVR, or amplifier supports the selected audio format.

IMPORTANT — Micro USB Can Be Used for Firmware Update and Control

The Micro USB port is used for firmware updates and can also be used for configuration and control from third-party control terminals.

The manual notes that the Micro USB port can be used as an RS-232 control port.

It supports Windows 8.1 / 10 / 11 and macOS 10.10 or above.

The Micro USB control baud rate is 57600.

Ports and Panel Layout

Step-by-Step Setup

1. Connect the included 5V/2A power adapter to the DC 5V port on the HDS-404MV. 
2. Connect your HDMI source devices to HDMI Input 1, Input 2, Input 3, and Input 4. 
   Examples include a PC, laptop, DVR, camera system, streaming device, Blu-ray player, DVD player, cable box, or media player. 
3. Connect HDMI Output A, Output B, Output C, and Output D to your TVs, monitors, projectors, or commercial displays. 
4. If using external audio, connect your audio system to either: 
   • 3.5mm Stereo output 
   • Toslink / S/PDIF Optical output 
5. Turn on the source devices, displays, audio system, and HDS-404MV. 
6. Use Output A/B/C/D buttons to select which HDMI input appears on each output. 
7. To use multiview mode, press MODE to cycle through the available layouts. 
8. Use MODIFY and the number buttons on the remote to change which HDMI inputs appear in each multiview window. 
9. Use PIP to enable Picture-in-Picture mode and cycle the PIP window location. 
10. Use SCALER to select the output resolution. 
11. Use AUDIO to choose which HDMI input audio is played. 
12. If using RS-232 or Micro USB control, connect the Micro USB port to a computer or third-party control terminal. 

HDMI Cable Requirement — Critical

For best performance, use high-quality HDMI cables.

The manual troubleshooting section lists the following cable guidance:

Poor-quality or longer HDMI cables may cause:

• No picture 
• Black screen 
• Signal light off 
• Screen splash 
• Pink screen 
• Signal dropouts 
• Multiview display issues 
• 4K@30Hz not working properly 

For troubleshooting, replace the HDMI cable, use shorter HDMI cables, and confirm that the input and output connections are correct.

Understanding Matrix / Seamless Switch Mode

In normal matrix mode, Output A, Output B, Output C, and Output D can each select one HDMI input.

Example:

Use this mode when each display should show one full-screen HDMI source.

Understanding Multiview Modes

The HDS-404MV supports multiple multiview modes.

Use multiview mode when several sources need to be monitored on one screen.

Understanding 2x2 Four Equal Picture Mode

In 2x2 mode, all four HDMI inputs are displayed on one screen.

Default layout:

Using MODIFY + number keys, the layout can be changed into different input arrangements.

This mode is useful for viewing four camera feeds, computers, media players, or monitoring sources at the same time.

Understanding Left / Right Picture Mode

Left / Right mode shows two HDMI sources side by side.

Default layout:

Use MODIFY + number key combinations to choose which input appears on the left side and which input appears on the right side.

This is useful for comparing two sources or monitoring two devices at once.

Understanding Up / Down Picture Mode

Up / Down mode shows two HDMI sources stacked vertically.

Default layout:

Use MODIFY + number key combinations to select the top and bottom input sources.

This is useful when two sources need to be viewed at the same time in a vertical split-screen layout.

Understanding One Big Three Small Mode

One Big Three Small mode shows one HDMI input as the larger image and the other inputs as smaller images.

Default layout:

Use MODIFY + number keys to choose which input becomes the large window.

This is useful when one main source needs priority while the other sources remain visible.

Understanding PIP Mode

PIP stands for Picture-in-Picture.

In PIP mode, one HDMI input appears as the main image and another HDMI input appears as a smaller window.

Default layout:

Use PIP + MODIFY + number key combinations to choose the main input and small input.

Press the PIP button to cycle the small window location.

The PIP window cycles through:

• Right lower corner 
• Left lower corner 
• Left upper corner 
• Right upper corner 

Understanding Output Resolution Scaling

The HDS-404MV includes built-in scaling.

The SCALER button switches the HDMI output resolution between:

Use 4K@30Hz when the connected display supports 4K@30Hz.

Use 1080p for older displays or troubleshooting.

Use scaler control if the display does not show video or if the selected resolution is not compatible.

Understanding Aspect Ratio Control

The HDS-404MV supports aspect ratio control.

The Full Screen button switches between:

• Full-screen mode 
• Original video ratio 

Use this when the multiview image appears stretched or when the user wants to preserve the original source aspect ratio.

Understanding Audio Selection

The HDS-404MV allows the user to choose which source audio is played.

The Audio button can select the audio source from Input 1 through Input 4.

Long pressing the Audio button for 3 seconds switches between:

• 2.1CH mode 
• 5.1CH mode 

Audio output options include:

If using stereo output, use a stereo-compatible audio format.

If using Toslink, make sure the connected audio device supports LPCM, AC3, or DTS as needed.

Understanding Power-Off Memory

The HDS-404MV includes power-off memory.

This means the device can retain the last setup after power off.

If the product is powered off and turned back on, it can restore the previous configuration instead of requiring the user to set the layout again.

Understanding the IR Remote

The included IR remote can control power, mute, source selection, multiview mode, PIP, copy mode, audio, scaling, source modification, aspect ratio, and OSD.

Understanding OSD Display

The OSD button shows on-screen display information.

The manual notes that the OSD content appears and disappears after approximately 3 seconds.

Use OSD when you need to quickly check the current device or display information.

RS-232 Control

The HDS-404MV supports RS-232 control through the Micro USB port.

Default RS-232 settings:

Important RS-232 notes:

• A carriage return is required at the end of each command string. 
• Commands are not case-sensitive. 
• Spaces shown in the manual are for clarity; commands should not include spaces. 
• The response ends with a carriage return followed by line feed. 

RS-232 commands can control:

• Power on / off 
• Global system status 
• Output source selection 
• Output on / off 
• 2x2 mode 
• Left / right picture mode 
• Up / down picture mode 
• One big three small mode 
• PIP mode 
• PIP window position 
• Output resolution scaling 
• Aspect ratio 
• External Optical and analog audio output 
• 2.1CH / 5.1CH audio mode 
• Audio input channel selection 
• OSD display 
• Front-panel button enable / disable 
• RS-232 baud rate 
• Factory reset 

Understanding Micro USB Control

The Micro USB port can be used for configuration and control from third-party control terminals.

It can also be used for firmware updates.

The manual notes:

If the computer operating system is too old, the CDC driver may need to be installed manually.

What Source Devices Is the HDS-404MV Compatible With?

The OREI HDS-404MV is compatible with HDMI source devices such as:

• PCs 
• Laptops with HDMI output 
• DVRs 
• Camera systems 
• Blu-ray players 
• DVD players 
• Streaming devices 
• Cable boxes 
• Satellite receivers 
• Set-top boxes 
• Media players 
• Game consoles with supported HDMI output 

For 4K@30Hz, the source device, HDMI cable, and display must all support 4K@30Hz.

What Displays Is the HDS-404MV Compatible With?

The HDS-404MV can connect to HDMI displays such as:

• TVs 
• Monitors 
• Projectors 
• Commercial displays 
• Security monitoring displays 
• Conference room displays 
• Classroom displays 
• Retail displays 
• Sports bar displays 

For 4K@30Hz output, the connected display must support 4K@30Hz over HDMI.

What Audio Devices Is the HDS-404MV Compatible With?

The HDS-404MV can send audio to:

• Toslink soundbars 
• AV receivers 
• Amplifiers 
• Powered speakers 
• Stereo speaker systems 
• HDMI TVs or HDMI audio systems 

Use Toslink for digital audio systems.

Use the 3.5mm stereo output for analog stereo audio systems.

Make sure the connected audio device supports the selected audio format.

Frequently Asked Questions

Q: What is the OREI HDS-404MV used for? 
A: The HDS-404MV is used to connect up to four HDMI source devices to up to four HDMI displays. It can work as a seamless matrix switcher or as a multiviewer that shows multiple HDMI sources on one screen.

Q: Is the HDS-404MV a matrix switch? 
A: Yes. It is a 4-input, 4-output HDMI matrix switch with multiviewer functionality.

Q: Is the HDS-404MV a multiviewer? 
A: Yes. It supports multiview layouts including 2x2, left/right, up/down, one-big-three-small, and PIP.

Q: Is the HDS-404MV a video wall controller? 
A: No. It is a multiviewer, not a video wall controller. It combines multiple sources on one screen but does not split one image across multiple displays.

Q: How many HDMI sources can I connect? 
A: You can connect up to four HDMI source devices.

Q: How many displays can I connect? 
A: You can connect up to four HDMI displays.

Q: Can Output A, B, C, and D show different sources? 
A: Yes. Each output can select HDMI Input 1, 2, 3, or 4 in normal switch mode.

Q: Can I show all four HDMI inputs on one screen? 
A: Yes. Use 2x2 four equal picture mode to show all four HDMI inputs on one screen.

Q: Can I show two HDMI sources side by side? 
A: Yes. Use left/right picture mode.

Q: Can I show two HDMI sources stacked vertically? 
A: Yes. Use up/down picture mode.

Q: Does it support PIP? 
A: Yes. PIP mode shows one main input with one smaller input window.

Q: Can I move the PIP window? 
A: Yes. Press the PIP button to cycle the small window position between screen corners.

Q: What does the COPY button do? 
A: COPY copies the Output A display mode to Output B, Output C, and Output D at the same time.

Q: Does the HDS-404MV support seamless switching? 
A: Yes. The manual lists seamless switching support.

Q: Does the HDS-404MV support 4K@60Hz? 
A: No. It supports up to 4K@30Hz.

Q: Does the HDS-404MV support 8K? 
A: No. It does not support 8K.

Q: Does the HDS-404MV support 4K@120Hz? 
A: No. It does not support 4K@120Hz.

Q: What HDMI version does the HDS-404MV support? 
A: It supports HDMI 1.4.

Q: What HDCP version does it support? 
A: It supports HDCP 1.4.

Q: Does the HDS-404MV have audio output? 
A: Yes. It includes 3.5mm stereo audio output and Toslink / S/PDIF digital audio output.

Q: What audio formats are supported? 
A: The manual lists LPCM, AC3, and DTS audio support.

Q: Can I choose which input audio plays during multiview? 
A: Yes. Use the Audio button to select which source audio is played from Input 1 through Input 4.

Q: What does long pressing the Audio button do? 
A: Long pressing the Audio button for 3 seconds switches between 2.1CH and 5.1CH mode.

Q: What output resolutions can I select? 
A: The Scaler button switches between 1080p, 2560x1600p, and 4K@30Hz output.

Q: What does the Full Screen button do? 
A: It switches between full-screen mode and keeping the original video ratio.

Q: Does the HDS-404MV remember the last setup after power off? 
A: Yes. The manual lists a power-off memory function.

Q: Does the HDS-404MV support RS-232 control? 
A: Yes. It supports RS-232 control through the Micro USB port.

Q: What is the default RS-232 baud rate? 
A: The default RS-232 baud rate is 57600.

Q: What is the Micro USB port used for? 
A: The Micro USB port is used for firmware updates and RS-232 serial control.

Q: What operating systems are supported for Micro USB control? 
A: The manual lists Windows 8.1 / 10 / 11 and macOS 10.10 or above.

Q: What should I do if there is no picture? 
A: Check that the power adapter is connected, the power switch is on, the HDMI input and output connections are correct, and try replacing the HDMI cables.

Q: What should I do if I see a splash screen or pink screen? 
A: Use a standard high-quality HDMI cable and keep cable length within the recommended limits.

Q: What HDMI cable length is recommended? 
A: The troubleshooting section states that for 1080p, input/output cable length should not exceed 10m to 10m, and for 4K@30Hz, it should not exceed 5m to 5m.

Q: Does the HDS-404MV need external power? 
A: Yes. Connect the included 5V/2A power adapter.