BK-41A Overview and Use Cases – OREI

What Is the BK-41A?

The OREI BK-41A is an 8K 4-port HDMI switch with audio extraction. It allows you to connect up to four HDMI source devices to one TV, monitor, or projector while also extracting audio through Optical and 3.5mm stereo outputs.

The BK-41A is useful for home theater, gaming, and commercial AV setups where users want to connect multiple devices such as a PS5, Xbox Series X, gaming PC, laptop, streaming device, Blu-ray player, or cable box to one display and route audio separately to a soundbar, AVR, amplifier, headphones, or speakers.

The BK-41A supports HDMI 2.1 and HDCP 2.3, with a video bandwidth of 48Gbps. It supports video resolutions up to 8K@60Hz, 4K@120Hz, and 1080p@240Hz. It also supports HDR10+, Dolby Vision, CEC, EDID management, and HDMI audio formats including LPCM, DTS, Dolby Digital, DTS-HD Master Audio, and Dolby TrueHD.

IMPORTANT — BK-41A Has Audio Extraction

The BK-41A includes two separate audio extraction outputs:

Optical output
3.5mm stereo output

This allows the selected HDMI source audio to be sent to an external soundbar, AVR, amplifier, speakers, or headphones.

The HDMI output still sends audio and video to the connected display as long as the display supports the selected format.

IMPORTANT — Audio Extraction Depends on the Audio Format

The BK-41A can extract audio through Optical and 3.5mm output, but the audio format must match the capabilities of the output being used.

The HDMI output can pass high-quality HDMI audio formats such as LPCM, Dolby Digital, Dolby TrueHD, DTS, DTS-HD Master Audio, etc.

The Optical output supports Dolby and DTS up to 5.1CH.

The 3.5mm analog output supports PCM 2CH stereo only.

If you are using the 3.5mm output, set your source device to PCM or Stereo. If the source is sending Dolby, DTS, Bitstream, or surround audio, the 3.5mm output will not work because it only supports stereo analog audio.

IMPORTANT — 8K and 4K@120Hz Requires HDMI 2.1 Equipment

To use 8K@60Hz, 4K@120Hz, or 1080p@240Hz, every part of the setup must support the required resolution and refresh rate.

This includes:

The HDMI source device
The TV, monitor, or projector
The HDMI cables

For 8K and high-refresh-rate video, use Ultra High-Speed Certified HDMI 2.1 cables under 15 feet.

IMPORTANT — CEC Support Is for Input 1 Only

The BK-41A supports CEC between the Output and Input 1 only.

Ports and Panel Layout

Port / LED / Button	Location	Function
Micro USB	Front panel	Used for firmware upgrade
Power Indicator	Front panel	LED lights up when active power is received
Output Indicator	Front panel	LED lights up when the HDMI output is connected to an active display
Input Indicators 1–4	Front panel	LEDs light up when the respective input is selected for output
Auto LED	Front panel	Lights up when automatic switching is enabled
IR LED	Front panel	Lights up when IR control is turned on
IR Receiver	Front panel	Receives signal from the included remote
Select Button	Front panel	Press once to switch to the next input source
EDID DIP Switches	Front panel	Used to change EDID modes
HDMI Inputs 1–4	Rear panel	Connect HDMI source devices such as game consoles, streaming devices, laptops, or Blu-ray players
HDMI Output	Rear panel	Connects to a TV, monitor, or projector
Stereo Output	Rear panel	3.5mm stereo audio output for soundbar, AVR, amplifier, speakers, or headphones
SPDIF Output	Rear panel	Optical audio output for soundbar, AVR, amplifier, or audio processor
DC 5V	Rear panel	Connect the included power adapter

Step-by-Step Setup

Connect the included power adapter to the DC 5V port on the BK-41A.
Connect your HDMI source devices to HDMI Input 1, Input 2, Input 3, and Input 4.
Examples include a PS5, Xbox Series X, gaming PC, laptop, streaming box, Blu-ray player, or cable box.
Connect the HDMI Output port on the BK-41A to your TV, monitor, or projector.
If using external audio, connect one of the audio outputs:
- Use Optical for a soundbar, AVR, amplifier, or audio system with Optical input.
- Use 3.5mm stereo for powered speakers, headphones, etc.
Turn on the source device, display, and audio system.
Use the Select button on the front panel or the included remote control to choose the HDMI input you want to display.
Set the EDID DIP switches based on the video and audio format needed for your setup.

HDMI Cable Requirement — Critical

For 8K@60Hz, 4K@120Hz, or 1080p@240Hz, use Ultra High-Speed Certified HDMI 2.1 cables under 15 feet.

Understanding Audio Extraction

The BK-41A can extract audio from the selected HDMI input and send it to the 3.5mm stereo or Optical output.

Output	Best Used For	Important Note
3.5mm Stereo	Powered speakers, headphones, stereo amplifiers	Use PCM / Stereo audio from the source
Digital Optical	Soundbars, AVRs, amplifiers, digital audio systems	Use a compatible Optical audio format such as PCM or Dolby Digital
HDMI Output	TV, monitor, AVR, or HDMI audio system	Passes HDMI audio with video

If there is no audio from either audio output, the audio format may not be compatible with the selected output.

EDID DIP Switch Settings

The BK-41A includes advanced EDID DIP switch settings.

0 = Switch Up
1 = Switch Down

Mode	DIP Status	EDID Setting
Mode 1	0000	Copy EDID from HDMI Output
Mode 2	1000	8Kx4K@60 4:2:0 / 8Kx4K@30 4:4:4 / 4Kx2K@120Hz 4:4:4, 48G, HDR10, 2CH Audio
Mode 3	0100	8Kx4K@60 4:2:0 / 8Kx4K@30 4:4:4 / 4Kx2K@120Hz 4:4:4, 48G, HDR10, Dolby/DTS 5.1
Mode 4	1100	8Kx4K@60 4:2:0 / 8Kx4K@30 4:4:4 / 4Kx2K@120Hz 4:4:4, 48G, HDR10, HD Audio
Mode 5	0010	4Kx2K@60, 18G, HDR10, 2CH Audio
Mode 6	1010	4Kx2K@60, 18G, HDR10, Dolby/DTS 5.1
Mode 7	0110	4Kx2K@60, 18G, HDR10, HD Audio
Mode 8	1110	4Kx2K@60, 10.2G, HDR10, 2CH Audio
Mode 9	0001	4Kx2K@60, 10.2G, HDR10, Dolby/DTS 5.1
Mode 10	1001	4Kx2K@60, 10.2G, HDR10, HD Audio
Mode 11	0101	1080p, 2CH Audio
Mode 12	1101	1080p, Dolby/DTS 5.1
Mode 13	0011	1080p, HD Audio
Mode 14	1011	1280x720p@60 DVI
Mode 15	0111	1920x1080p@60 DVI
Mode 16	1111	4Kx2K@30, 10.2G, HDR, 2CH Audio

Use 2CH Audio modes when using the 3.5mm stereo output.

Use Dolby/DTS 5.1 modes when using Optical with a compatible surround sound device.

Use Mode 1 if you want the source device to follow the EDID from the connected display.

IMPORTANT — Auto Switching Depends on HDMI 5V Signal Detection

The BK-41A 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-41A 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-41A 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-41A 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.

Understanding the Remote Control

The included remote can control the main functions of the BK-41A.

Remote Button	Function
Power	Turns the switch on or off
Inputs 1–4	Selects the respective HDMI input source
IR	Turns the IR receiving function on or off

If the remote is not working, check that IR control is turned on and that the IR LED is lit.

What Source Devices Is the BK-41A Compatible With?

The OREI BK-41A is compatible with HDMI source devices such as:

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

For 8K@60Hz, 4K@120Hz, 1080p@240Hz, HDR10+, or Dolby Vision, the source device, display, and HDMI cables must all support the required format.

What Displays Is the BK-41A Compatible With?

The BK-41A can connect to HDMI displays such as:

TVs
Monitors
Projectors
Gaming monitors
Commercial displays

What Audio Devices Is the BK-41A Compatible With?

The BK-41A can send extracted audio to:

Soundbars with Optical input
AVRs with Optical input
Amplifiers with Optical input
Powered speakers with 3.5mm input
Headphones with 3.5mm connection
Stereo amplifiers

For 3.5mm stereo output, set the source to Stereo or PCM.

For Optical output, set the source to a compatible digital audio format such as PCM or Dolby Digital.

Frequently Asked Questions

Q: What is the OREI BK-41A used for?
A: The BK-41A is used to connect up to four HDMI source devices to one display while also extracting audio through Optical or 3.5mm stereo output.

Q: Does the BK-41A support HDR and Dolby Vision?
A: Yes. It supports HDR10+ and Dolby Vision.

Q: Why am I not getting audio from the 3.5mm output?
A: Set the source device audio format to Stereo or PCM. The 3.5mm output requires a compatible stereo format.

Q: What audio formats does the BK-41A support?
A: It supports uncompressed LPCM and compressed DTS/Dolby Digital formats, including DTS-HD Master Audio and Dolby TrueHD through HDMI.

Q: Does HDMI audio still pass to the TV?
A: Yes. HDMI audio can pass through the HDMI output to the TV, depending on the connected device and EDID setting.

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. For faster switching, you need an HDMI Switch that supports Seamless 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-41A 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-41A 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.