BK-931 Overview and Use Cases – OREI

What Is the BK-931?

The OREI BK-931 is an HDMI 2.1 audio extractor designed to separate high-quality audio from an HDMI signal while maintaining full-bandwidth video output to a display. It supports resolutions up to 8K at 60Hz and 4K at 120Hz, making it well-suited for advanced gaming systems and modern home theater setups.

The BK-931 is placed between an HDMI source, such as a gaming console, PC, or streaming device and a TV, Projector or monitor. It passes the video signal directly to the display while extracting and routing audio to an external sound system via eARC/ARC or other audio outputs, enabling immersive formats like Dolby Atmos and DTS:X.

IMPORTANT — BK-931 Supports eARC/ARC Audio from the TV

The OREI BK-931 can extract audio not only from connected HDMI source devices like a PS5, Xbox, PC, or streaming box, but also directly from your TV through its eARC/ARC connection. This allows the BK-931 to route audio from your TV’s internal apps such as Netflix, Disney+, or YouTube back through the extractor and into a connected soundbar or AV receiver. As a result, it is especially useful in setups where the TV acts as the primary media hub, enabling both external devices and built-in apps to deliver high-quality audio through a single audio system, provided that ARC/eARC is properly enabled and configured. To use audio from your TV’s apps, press the eARC button on the unit to switch the audio source from the connected HDMI device to the TV’s ARC/eARC return channel.

Ports and Panel Layout

Port / LED	Location	Function
SOURCE IN	Rear panel	Use this port to connect a source device
TV OUT (eARC)	Rear panel	Connect a display device or even an ARC/eARC TV if you want to extract audio
eARC OUT (soundbar)	Rear panel	Connect to an audio device with an ARC/eARC port
AUDIO OUT Amp	Rear panel	Connect to an audio device with a standard HDMI input port
OPTICAL	Rear panel	Connect to an audio device with an optical input
L/R	Rear panel	Connect to an audio device with a 3.5 mm input
DC 5V	Rear panel	Connect the power adapter
POWER LED (RED)	Front panel	Indicates the power status
IN LED (GREEN)	Front panel	Lights up when an input signal is detected
OUT LED (GREEN)	Front panel	Lights up when a display is connected to the output
AMP LED (GREEN)	Front panel	Lights up when an amplifier/AVR is connected to the AMP output port.
eARC LED (GREEN)	Front panel	Indicates the status of ARC/eARC based on if the LED is on, flashing, or off.
eARC BUTTON	Front panel	Press this button to enable or disable eARC return from the TV.
EDID DIP SWITCH	Front panel	Use this switch to set EDID. 1=on, 0-off
SERVICE (USB-C)	Front panel	Used for firmware updates and debugging

Step-by-Step Setup

Connect your HDMI source device (PS5, Xbox, PC, or streaming device) to the SOURCE IN port on the OREI BK-931 using a high-speed HDMI cable.
Connect the TV OUT (eARC) port on the BK-931 to your TV using an HDMI cable, preferably into a port that supports 4K at 120Hz or 8K.(Connect the cable to the eARC/ARC port on your TV if you want to extract audio from the TV’s internal apps.)
Connect your audio system to the BK-931 using HDMI (eARC/ARC), HDMI (Audio-only), Optical (TOSLINK), or the 3.5mm output.
Plug in the power adapter and turn on the BK-931.
Set your source device audio output to bitstream, Dolby Atmos, or DTS:X if supported.
Test the setup using both an HDMI source and your TV’s internal apps to confirm video output and proper audio routing.

Note: Enable ARC or eARC in your TV settings, set audio output to external speakers or HDMI ARC, and select bitstream or passthrough audio format.

HDMI Cable Requirement — Critical

Use HDMI 2.1 Ultra High Speed cables (48Gbps certified) for all connections

OREI recommends cables under 15 feet for reliable 8K or 4K@120Hz signal integrity.

IMPORTANT

The OREI BK-931 supports multiple audio output formats depending on which ports you use. The HDMI eARC Soundbar port and HDMI Amp OUT can deliver up to 7.1-channel audio, including formats like Dolby Atmos and DTS:X, while the optical output supports up to 5.1-channel formats such as Dolby Digital and DTS 5.1. The 3.5mm (L/R) output is limited to 2-channel stereo audio. You can connect all outputs at the same time, but doing so will force the system to match the lowest common audio format. For example, if you connect both an eARC soundbar and headphones via the 3.5mm output while your source is set to Dolby Atmos, only the soundbar will produce audio. To get sound from both the soundbar and headphones simultaneously, you’ll need to set the source audio format to PCM or stereo.

What Sound Bars or AVRs is the BK-931 Compatible with?

The OREI BK-931 is compatible with a wide range of audio systems, including soundbars, AV receivers, Amplifiers, and headphones making it flexible for both modern and older setups. It works with devices that support HDMI eARC or ARC, or regular HDMI allowing high-quality audio formats like Dolby Atmos and DTS:X to be transmitted when supported. In addition, it can connect to audio systems using optical (TOSLINK) or 3.5mm outputs, making it suitable for soundbars or receivers that do not have HDMI. This broad compatibility allows the BK-931 to integrate easily with both advanced home theater systems and more basic audio setups.

What source devices is the BK-931 Compatible with?

The OREI BK-931 is compatible with a wide variety of HDMI source devices, making it ideal for both gaming and media playback. It works with modern gaming consoles such as PlayStation and Xbox systems, as well as PCs and laptops with HDMI output. The device also supports Blu-ray and Ultra HD Blu-ray players, along with popular streaming devices like Roku, Apple TV, Amazon Fire TV, and similar media players. As long as the device outputs audio and video over HDMI, the BK-931 can extract and route its audio while passing the video signal through to a connected display.

Frequently Asked Questions

Q: What does the OREI BK-931 do?

A: The OREI BK-931 is an HDMI 2.1 audio extractor that separates audio from an HDMI signal while passing full-quality video to your TV, Projector or monitor. It also supports extracting audio from your TV through ARC or eARC.

Q: Does it support 4K 120Hz and 8K video?

A: Yes, the BK-931 supports up to 4K at 120Hz and 8K at 60Hz , making it suitable for next-generation gaming and high-resolution video.

Q: Can it extract audio from my TV’s built-in apps?

A: Yes, when connected to your TV’s ARC or eARC port, the BK-931 can extract audio from internal apps like Netflix, YouTube, and Disney+ and send it to your sound system. Make sure the eARC LED on the front is turned on by pressing the eARC button.

Q: Will this work with older TVs or receivers?

A: Yes, the BK-931 can help bridge compatibility gaps by allowing newer HDMI 2.1 sources to work with older audio equipment using HDMI Audio Only, Optical or 3.5mm connections, though some advanced features may be limited.

Q: I have a media source, a normal TV and an eARC Soundbar, and I want to send audio to a pair of Optical or 3.5mm input hearing aids while maintaining Dolby Atmos on the Soundbar. Would this work?

A: Unfortunately, that is not possible. If you connect a pair of hearing aids to the Optical or 3.5mm port while also connecting an eARC Soundbar. If the audio format from the media source is set to Dolby Atmos, only the Soundbar will output audio. In order to get audio from the Optical or 3.5mm port at the same time, the audio format needs to be set to Dolby Digital or PCM/Stereo. The same applies if you have an eARC TV that you are extracting the audio from. To allow Dolby Atmos to pass through and send Stereo or Dolby Digital to the Optical or 3.5mm ports, you need an Audio Extractor with Downmix technology.