BK-401ARC Overview and Use Cases

What Is the BK-401ARC?

The OREI BK-401ARC is an 8K 4x1 HDMI switch with ARC/eARC support. It allows you to connect up to four HDMI source devices to one TV, monitor, or projector while also providing audio extraction through Optical and 3.5mm L/R outputs.

It is useful for setups where you want to connect multiple HDMI devices such as a PS5, Xbox, Blu-ray player, PC, laptop, streaming device, or cable box to one display without constantly unplugging and reconnecting HDMI cables.

The BK-401ARC supports HDMI 2.1 and HDCP 2.3, with a video bandwidth of 48Gbps FRL and 18Gbps TMDS. It supports video resolutions up to 8K@60Hz 4:2:0 12-bit, 8K@30Hz 4:4:4 12-bit, and 4K@120Hz 4:4:4 12-bit. It also supports HDR, HDR10, HDR10+, Dolby Vision, HLG, VRR, ALLM, QMS, QFT, and SBTM pass-through. 

The BK-401ARC also supports ARC/eARC, allowing an ARC/eARC soundbar or amplifier to be connected through the IN 1(eARC) port and extract audio from the connected ARC/eARC supporting TV.

IMPORTANT — BK-401ARC Supports ARC/eARC Soundbars Through IN 1(eARC)

The BK-401ARC supports ARC/eARC audio routing through the IN 1(eARC) port.

When ARC/eARC is enabled, the IN 1(eARC) port can be used to connect an ARC/eARC soundbar or amplifier. This allows audio from the TV connected to the OUT (eARC) port to return back through the BK-401ARC and play through the connected ARC/eARC soundbar.

This is useful when you want audio from TV internal apps such as Netflix, YouTube, Disney+, Prime Video, or Hulu to play through your ARC/eARC soundbar.

To use this setup, your TV must support ARC or eARC, and the BK-401ARC OUT (eARC) port must be connected to the TV’s ARC/eARC HDMI port.

The BK-401ARC does NOT extract audio directly from the connected media sources and send to an eARC Soundbar, if your TV does not support ARC or eARC.

IMPORTANT — IN 1(eARC) Changes Function When ARC/eARC Is Enabled

The IN 1(eARC) port has two different functions depending on whether ARC/eARC is turned on or off.

When ARC/eARC is turned off, IN 1(eARC) works like a normal HDMI input for a source device.

When ARC/eARC is turned on, IN 1(eARC) is used for connecting an ARC/eARC soundbar or amplifier. In this mode, it can output audio from the TV or from the selected HDMI source, depending on which input is selected.

Because of this, customers should not expect IN 1(eARC) to behave like a normal source input while ARC/eARC mode is being used for a soundbar.

IMPORTANT — IN 1 May Lock Auto Switching When Used for ARC/eARC

When ARC/eARC is turned on and IN 1 is selected for ARC/eARC soundbar use, the IN 1 channel becomes locked.

In this condition, other HDMI input channels may not be detected automatically, even if auto switching is enabled. For example, if IN 3 is connected to a source device, the BK-401ARC may not automatically switch to IN 3 because IN 1 is locked for ARC/eARC operation. 

If you want to switch to another HDMI source while using ARC/eARC mode, use the SWITCH button or the remote control to manually select the desired input.

IMPORTANT — Audio Extraction Depends on the Audio Format 

The BK-401ARC includes both Optical and 3.5mm L/R audio outputs.

The Optical output supports LPCM 2.0CH, Dolby, and DTS 5.1CH audio.

The 3.5mm L/R output supports LPCM 2.0CH stereo audio only. 

If you are using the 3.5mm L/R output, the source device or TV should be set to PCM or Stereo audio. If the source is outputting Dolby, DTS, Dolby Atmos, or another surround format, the 3.5mm output will not produce audio.

Ports and Panel Layout

Step-by-Step Setup

1. Connect the included 5V/1A power adapter to the DC 5V port on the BK-401ARC. 
2. Connect the OUT (eARC) port on the BK-401ARC to your TV, monitor, or projector using an HDMI cable. 
3. Connect your HDMI source devices to the HDMI input ports. 
   Examples include a PS5, Xbox, Blu-ray player, PC, laptop, streaming box, or cable box. 
4. If you are using Optical or 3.5mm audio extraction, connect your audio device to the Optical or L/R output. 
5. Turn on your HDMI source device, TV/display, and audio system. 
6. Use the SWITCH button on the front panel or the included remote control to select the source you want to display. 
7. If using ARC/eARC with a soundbar, connect the soundbar to the IN 1(eARC) port, connect the OUT (eARC) port to the TV’s ARC/eARC HDMI port, and enable ARC/eARC on both the TV and BK-401ARC. 
8. Set the EDID DIP switch based on the video and audio format needed for your setup. 

HDMI Cable Requirement — Critical

For 8K and 4K@120Hz pass-through use Ultra High-Speed Certified HDMI 2.1 cables under 15 feet.

Understanding the eARC Button and eARC LED

The eARC button turns the ARC/eARC function on or off.

The eARC LED shows the current ARC/eARC status:

If the eARC LED is flashing, check that the HDMI cable is connected to the correct ARC/eARC HDMI port on the TV and that ARC/eARC and CEC are enabled in the TV settings.

Understanding Manual, Remote, and Auto Switching

The BK-401ARC supports manual switching, remote control switching, and auto switching.

Manual Switching

Press the SWITCH button on the front panel to switch between connected HDMI sources.

The SWITCH button cycles through the connected media sources. The corresponding input LED will turn on to show which source is selected.

Remote Control Switching

The included remote allows direct input selection.

Press 1, 2, 3, or 4 on the remote to select the corresponding HDMI input.

The remote also includes:

Auto Switching

The BK-401ARC supports auto switching.

Press and hold the SWITCH button for about 3 seconds to turn auto switching on or off. The AUTO LED will turn on when auto switching is enabled.

Note: When IN 1 is selected and locked for ARC/eARC use, other input channels may not be detected automatically even if auto switching is enabled. 

IMPORTANT — Auto Switching Depends on HDMI 5V Signal Detection

The BK-401ARC 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-401ARC 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-401ARC 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-401ARC 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.

Note: When IN 1 is selected and locked for ARC/eARC use, other input channels may not be detected automatically even if auto switching is enabled.

EDID DIP Switch Settings

The BK-401ARC includes advanced EDID management, allowing the user to control what video and audio capabilities the connected source devices detect.

1 = UP | 0 = DOWN

Use a 2CH PCM EDID mode when using the 3.5mm L/R output.

Use a 5.1CH mode when using Optical with a Dolby/DTS-capable soundbar, AVR, or amplifier.

Use a 7.1CH or HD audio mode when the connected HDMI or eARC audio device supports higher audio formats such as Dolby TrueHD, Dolby Atmos, DTS-HD Master Audio, or DTS:X.

ARC/eARC Setup Examples

Situation 1 — ARC/eARC Off

When ARC/eARC is turned off, the BK-401ARC works like a standard 4x1 HDMI switch with audio extraction.

In this setup:

• HDMI source devices connect to IN 1, IN 2, IN 3, and IN 4
• The TV connects to OUT (eARC)
• Optical and L/R outputs extract audio from the selected HDMI source

This setup is useful when you want audio from the selected media source to play through an Optical soundbar, amplifier, powered speakers, or 3.5mm audio system.

Situation 2 — ARC/eARC On, TV App Audio to Soundbar

When ARC/eARC is turned on and IN 1 is selected, the IN 1(eARC) port can be connected to an ARC/eARC soundbar.

In this setup, audio from the TV connected to the OUT (eARC) port can return through the BK-401ARC and play through the soundbar.

This is useful for TV internal apps such as Netflix, YouTube, Disney+, Prime Video, or Hulu.

The TV must support ARC/eARC for this setup to work.

Situation 3 — ARC/eARC On, Source Audio to Soundbar

When ARC/eARC is turned on and Input 2, 3, or 4 is selected, the soundbar connected to IN 1(eARC) can receive audio from the selected HDMI source. However, the TV still needs to support ARC/eARC, because the audio isn’t going directly from the media source to the Soundbar, instead it’s travelling through the TV first and then to the soundbar through the eARC connection.

What Soundbars, AVRs, or Speakers Is the BK-401ARC Compatible With?

The BK-401ARC is compatible with several types of audio devices depending on the output being used.

For ARC/eARC, it can work with ARC/eARC soundbars or amplifiers like the Sonos ARC, Sonos Beam (Gen 2), Bose Smart Soundbar 600 & 900, etc.

For Optical audio, it can work with soundbars, AVRs, amplifiers, and speaker systems that support Optical/TOSLINK input and compatible audio formats such as LPCM 2.0CH, Dolby, or DTS 5.1CH.

For 3.5mm L/R audio, it can work with powered speakers, headphones, stereo amplifiers, or other analog stereo audio devices, as long as the source or TV is set to PCM/Stereo.

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

The OREI BK-401ARC is compatible with HDMI source devices such as:

• PlayStation 5 
• Xbox Series X/S 
• Nintendo Switch 
• Gaming PCs 
• Laptops with HDMI output 
• Blu-ray players 
• DVD players 
• Apple TV 
• Roku 
• Fire TV 
• NVIDIA Shield 
• Cable boxes 
• Satellite receivers 
• Other HDMI media players 

For 8K@60Hz or 4K@120Hz, the connected source device must support that resolution and refresh rate.

What Displays Is the BK-401ARC Compatible With?

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

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

For ARC/eARC use, the TV must have an ARC/eARC HDMI port.

For high-resolution or high-refresh-rate output, the connected display must support the selected video format.

Frequently Asked Questions

Q: What is the OREI BK-401ARC used for? 
A: The BK-401ARC is used to connect up to four HDMI source devices to one TV, monitor, or projector. It also supports ARC/eARC soundbar connection and audio extraction through Optical and 3.5mm outputs.

Q: Can the BK-401ARC show two sources at the same time? 
A: No. The BK-401ARC can only display one selected HDMI source at a time.

Q: Does the BK-401ARC support ARC/eARC? 
A: Yes. The BK-401ARC supports ARC/eARC. Connect the TV to the OUT (eARC) port and connect the ARC/eARC soundbar to the IN 1(eARC) port when using ARC/eARC mode.

Q: Can I get audio from my TV’s built-in apps? 
A: Yes, if your TV supports ARC/eARC, the audio from TV apps can return from the TV through the OUT (eARC) port and play through the eARC soundbar connected to IN 1(eARC).

Q: Can I use IN 1 as a normal HDMI input? 
A: Yes, when ARC/eARC is turned off. When ARC/eARC is turned on, IN 1(eARC) is used for ARC/eARC soundbar connection.

Q: Why is auto switching not working while using ARC/eARC? 
A: When IN 1 is selected for ARC/eARC use, the IN 1 channel is locked. In this condition, other input channels may not be automatically detected even if auto switching is enabled.

Q: Does the BK-401ARC support Dolby Atmos? 
A: Yes. HDMI and eARC audio support includes Dolby Atmos, Dolby TrueHD, DTS-HD Master Audio, DTS:X, and other advanced audio formats when the connected devices support them.

Q: Does the Optical output support Dolby Atmos? 
A: No. The Optical output supports LPCM 2.0CH, Dolby, and DTS 5.1CH. Optical does not support high-bandwidth formats such as Dolby TrueHD, Dolby Atmos, DTS-HD Master Audio, or DTS:X.

Q: Why is there no audio from the 3.5mm L/R output? 
A: The 3.5mm L/R output supports LPCM 2.0CH stereo only. Set the source device or TV audio output to PCM or Stereo.

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.

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-401ARC 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-401ARC 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.