BK-401C Overview and Use Cases

What Is the BK-401C?

The OREI BK-401C is an 8K 4x1 HDMI switch with USB-C input. It allows you to connect up to four media source devices to one TV, monitor, or projector.

The BK-401C includes three HDMI inputs and one USB-C input. This makes it useful for setups where you want to connect HDMI devices such as a PC, DVD/Blu-ray player, TV box, or gaming console, along with a USB-C laptop or computer, to one display.

The BK-401C supports HDMI 2.1, HDCP 2.3, and DP 1.4. The HDMI inputs support video resolutions up to 8K@60Hz 4:2:0 12-bit and 4K@120Hz 4:4:4 12-bit. The USB-C input supports up to 8K@30Hz 4:2:2 10-bit and 4K@120Hz 4:2:2 10-bit. It also supports HDR10+, Dolby Vision, VRR, ALLM, FVA, CEC, and audio formats such as LPCM, Dolby TrueHD, Dolby Atmos, DTS-HD Master Audio, and DTS:X. 

The BK-401C supports front-panel switching, remote control switching, and automatic switching.

IMPORTANT — Input 4 Is USB-C, Not HDMI

The BK-401C has three HDMI inputs and one USB-C input.

Inputs 1, 2, and 3 are HDMI inputs.

Input 4 is a USB-C input.

Use Input 4 for a compatible USB-C laptop or computer. 

IMPORTANT — USB-C Video Requires DP Alt Mode / or Thunderbolt technology

The USB-C input is based on DP 1.4 video input.

For the USB-C input to work, the connected USB-C device must support video output through USB-C, commonly called DP Alt Mode.

Not every USB-C port supports video. Some USB-C ports only support charging or data. Make sure your PC or laptop has a USB-C port that supports DP Alt Mode or Thunderbolt technology.

IMPORTANT — HDMI and USB-C Inputs Have Different Maximum Resolutions

The HDMI and USB-C inputs do not have the exact same maximum video specification.

This means 8K@60Hz is supported through the HDMI inputs, not through the USB-C input.

IMPORTANT — 8K and 4K@120Hz Require Compatible Equipment

To use 8K, 4K@120Hz, HDR10+, Dolby Vision, VRR, ALLM, or FVA, every part of the setup must support the required format.

This includes:

• The HDMI or USB-C source device 
• The TV, monitor, or projector 
• The HDMI or USB-C cable 

For HDMI 8K or 4K@120Hz signals, use Ultra High-Speed Certified HDMI 2.1 cables under 15 feet.

For USB-C video, use a USB-C cable that supports high-bandwidth video output.

IMPORTANT — BK-401C Does Not Have Audio Extraction

The BK-401C supports HDMI audio pass-through, but it does not have separate audio extraction outputs.

There is no Optical output, 3.5mm output, RCA output, or HDMI Audio Only output.

Audio passes through the HDMI output to the connected TV or monitor.

If you need separate audio extraction, use a model with dedicated audio outputs such as the BK-401A or BK-401ARC.

Ports and Panel Layout

Step-by-Step Setup

1. Connect the included 5V/1A power adapter to the DC 5V port on the BK-401C. 
2. Connect your HDMI source devices to HDMI IN 1, HDMI IN 2, and HDMI IN 3. 
   Examples include a DVD player, Blu-ray player, TV box, gaming console, or PC. 
3. Connect your USB-C source device to IN 4. 
   Examples include a USB-C laptop or desktop computer that supports video output through USB-C. 
4. Connect the HDMI OUT port on the BK-401C to your TV, monitor, or projector. 
5. Turn on the source devices and display. 
6. Use the SWITCH button on the front panel or the included remote control to select the input you want to display. 
7. Set the EDID DIP switch based on the video and audio format needed for your setup. 

HDMI Cable Requirement — Critical

For best performance with 4K@120Hz or 8K content, use Ultra High-Speed Certified HDMI 2.1 cables under 15 feet.

Understanding Manual and Auto Switching

The BK-401C supports both manual switching and automatic switching.

Manual Switching

Short press the SWITCH button on the front panel to move to the next input.

You can also use the included remote control to select Input 1, 2, 3, or 4 directly.

Auto Switching

Press and hold the SWITCH button for about 3 seconds to enable or disable auto switching.

When auto switching is enabled, the AUTO LED will light up.

Auto switching allows the BK-401C to switch to an active input automatically. However, auto switching depends on how the connected source devices behave. Some devices remain active in standby mode, which may affect automatic switching.

IMPORTANT — Auto Switching Depends on HDMI 5V Signal Detection

The BK-401C supports auto switching, but it works by detecting the 5V signal coming from the connected HDMI source device.

In simple terms, the switch looks for which HDMI source appears to be “active.”

If one source is connected and then another source is plugged in or powered on, the BK-401C can automatically switch to the newly detected source.

However, many modern streaming devices do not fully turn off. Devices such as Apple TV, Fire TV Stick, Google Chromecast, Roku, and similar media players often go into standby mode instead of shutting down completely. Even in standby, they may continue sending a 5V signal through HDMI.

Because of this, the BK-401C may still detect that device as active, even when the customer thinks it is “off.”

For example:

If you have an Apple TV connected to Input 1 and a PlayStation 5 connected to Input 2, the BK-401C may switch to Apple TV when the PS5 is turned off because the Apple TV is still sending an HDMI 5V signal.

But when you later turn the PS5 back on, the switch may not automatically switch away from Apple TV because the Apple TV never fully stopped sending its HDMI 5V signal.

In this type of setup, manual switching using the front panel button or included remote may be needed.

EDID DIP Switch Settings

The BK-401C includes an EDID DIP switch for managing video and audio compatibility.

1 = UP | 0 = DOWN

Use 2CH PCM modes when connecting to a stereo-only TV or monitor.

Use 5.1CH or 7.1CH modes when the connected TV, Projector or monitor supports surround sound.

Use the default copy EDID mode when you want the source device to follow the connected display’s reported capabilities.

What Source Devices Is the BK-401C Compatible With?

The OREI BK-401C can work with HDMI source devices such as:

• Blu-ray players 
• DVD players 
• Gaming consoles 
• TV boxes 
• Streaming devices 
• Desktop PCs 
• Media players 
• Cable boxes 
• Satellite receivers 

It can also work with compatible USB-C source devices such as:

• USB-C laptops 
• USB-C desktop computers 

For 8K, 4K@120Hz, HDR10+, Dolby Vision, VRR, or ALLM, the source device, display, and cables must all support the required format.

What Displays Is the BK-401C Compatible With?

The BK-401C can be connected to HDMI displays such as:

• TVs 
• Monitors 
• Projectors 
• Gaming monitors 
• Commercial displays 

Frequently Asked Questions

Q: What is the OREI BK-401C used for? 
A: The BK-401C is used to connect up to four source devices to one display. It has three HDMI inputs and one USB-C input.

Q: Does the USB-C input work with every USB-C device? 
A: No. The USB-C source device (laptop or computer) must support video output through USB-C, commonly called DP Alt Mode. Check your laptop or computer’s specification to confirm if it supports DP Alt Mode or Thunderbolt technology.

Q: Does the USB-C input support 8K@60Hz? 
A: No. The manual lists USB-C video support up to 8K@30Hz 4:2:2 10-bit or 4K@120Hz 4:2:2 10-bit.

Q: What audio formats does the BK-401C support? 
A: It supports LPCM, Dolby Digital/Plus/EX, Dolby TrueHD, Dolby Atmos, DTS, DTS-EX, DTS-96/24, DTS High Res, DTS-HD Master Audio, and DSD.

Q: Does the BK-401C support auto switching? 
A: Yes. Press and hold the SWITCH button for about 3 seconds to enable or disable auto switching.

Q: Does auto switching work with Apple TV, Fire TV Stick, Chromecast, or Roku? 
A: Auto switching may not work consistently with these devices because they often stay in standby mode and continue sending a 5V HDMI signal. The BK-401C may still detect them as active even when they appear to be off.

Q: Why does the switch stay on Apple TV even when I turn on my PS5? 
A: Apple TV may still be sending a 5V HDMI signal while in standby. Since the BK-401C still sees Apple TV as active, it may not automatically switch to the PS5. Use the front button or remote to switch manually. This applies to other devices such as Fire TV Stick, Roku Stick, Chromecast, etc. as well.

Q: Why do I see a black screen when switching inputs? 
A: This is normal. The display needs time to detect the new HDMI signal and complete the HDMI handshake. The delay can vary depending on the display, source device, resolution, refresh rate, and HDMI cables. The BK-401C is not a seamless switch. When switching inputs, the display will usually go black for a second or two while the HDMI signal reconnects. For faster switching, you need a Seamless Switch.