BK-108 Overview and Use Cases – OREI

What Is the BK-108?

The OREI BK-108 is an 8K 1x8 HDMI Splitter that takes a single HDMI 2.1 source and distributes it to eight HDMI displays simultaneously. It supports video resolutions up to 8K@60Hz 4:2:0 12-bit and 4K@120Hz 4:4:4 12-bit, with 48Gbps FRL bandwidth and HDMI 2.1/HDCP 2.3 compliance. All eight outputs carry an identical, synchronized copy of the input signal.

The BK-108 is the highest-performance 1x8 splitter in the OREI lineup. In addition to 8K pass-through, it features automatic downscaling (8K to 4K, or 8K/4K to 1080P), automatic HDR to SDR conversion for displays that do not support HDR, full HDR pass-through (HDR10, HDR10+, Dolby Vision, HLG), VRR, ALLM, QMS, QFT, and SBTM support, and an EDID DIP switch. It does not support CEC.

IMPORTANT — BK-108 Sends the Same Source to All 8 Outputs

The BK-108 is a splitter, not a switcher. It accepts one HDMI source and mirrors that signal to all eight outputs simultaneously.

All eight connected displays will always show the same content. You cannot send different sources to different outputs.
The BK-108 does not support CEC — you cannot turn all displays on or off using a single TV remote.
It does not have an audio extraction port. Audio is passed through the HDMI outputs only.
The BK-108 does not support 8K DSC (Display Stream Compression) input — downscaling will not function if the source uses 8K DSC format.

IMPORTANT — Auto Downscaling and HDR-to-SDR Conversion

The BK-108 includes intelligent auto downscaling that works differently from simpler splitters. Rather than forcing a fixed resolution, it reads the EDID of all connected displays and automatically selects the minimum resolution supported across all outputs:

If all displays support 8K, all outputs receive 8K.
If any display supports only 4K, all outputs are downscaled to 4K SDR — including the 8K displays.
If any display supports only 1080P, all outputs are downscaled to 1080P SDR.
Automatic HDR to SDR conversion is also applied when the minimum resolution output is lower than the source. This means HDR content will be tone-mapped to SDR for outputs going to non-HDR displays.
If the downscaled output is 1080P DVI (determined by EDID), there will be no audio on those displays.

For best results in mixed-display environments, set the EDID DIP switch to a fixed profile rather than relying on auto EDID copy, so the source outputs a consistent resolution regardless of what individual displays report.

IMPORTANT — 8K Requires HDMI 2.1 Cables Under 3 Meters

Achieving 8K output through this splitter requires every component in the chain to be 8K-capable:

The source device must output 8K over HDMI 2.1 (e.g., an 8K PC, 8K Blu-ray player, or compatible gaming console).
All cables must be Ultra High Speed HDMI 2.1 certified and no longer than 3 meters (10 ft) for 8K signals.
Connected displays must support 8K resolution via HDMI 2.1 to receive a native 8K signal. Displays that do not support 8K will receive a downscaled signal per the auto downscaling rules above.
For 4K@60Hz, use HDMI 2.0 cables up to 8 meters. For 4K@24Hz or 1080P, longer cables are acceptable — see the Cable Requirement section below.

Ports and Panel Layout

Port / Switch / LED	Location	Function
Power LED	Front panel	Red LED that lights up when the device is powered on.
IN LED	Front panel	Green LED that lights up when the HDMI IN port is connected to an active source device.
OUT LEDs (1–8)	Front panel	Green LEDs that light up when a display device is connected to the corresponding output port.
EDID DIP Switch	Front panel	3-position DIP switch for setting the EDID profile. Factory default (111) copies the EDID from the OUT 1 display. Other settings allow fixed 4K60 or 8K modes with different audio channel configurations (2.0CH, 5.1CH, 7.1CH). FRL12G settings support up to 8K@60Hz; FRL10G settings support 8K@30Hz and lower.
SERVICE	Front panel	USB Type-C port used for firmware updates only.
HDMI IN	Rear panel	Single HDMI 2.1 input port. Connect your source device such as an 8K Blu-ray player, gaming console, or streaming device.
HDMI OUT 1–8	Rear panel	Eight HDMI 2.1 output ports. Connect display devices such as 8K TVs, 4K TVs, or 1080P monitors.
DC 12V	Rear panel	Connect the included 12V/2.5A power adapter.

Step-by-Step Setup

Connect your HDMI 2.1 source device (such as an 8K Blu-ray player, gaming console, or PC) to the HDMI IN port on the rear panel.
Connect up to eight displays to the HDMI OUT 1 through HDMI OUT 8 ports on the rear panel. Unused ports can remain empty.
Connect the included 12V/2.5A power adapter to the DC 12V port on the rear panel. The red Power LED on the front panel will light up.
Set the EDID DIP switch on the front panel before powering the source. The factory default (111) copies the EDID from the OUT 1 display. For a fixed 8K setup, use settings 101–000. For a fixed 4K@60Hz setup, use 110. See the EDID section below for full details.
Power on the source device and all connected displays. The green IN LED will light up when a source is detected. The green OUT LEDs will light up for each output with an active display connected.
The splitter will automatically compare all connected display EDIDs and apply downscaling and HDR-to-SDR conversion as needed. 8K-capable displays will receive 8K; others will receive a downscaled signal.
If no picture appears, check cable connections, try a different EDID setting, ensure the source is outputting a supported resolution, and try shorter Premium High Speed HDMI cables.

Cable Requirement — Important

Cable quality and length are critical at higher resolutions. Use Premium High Speed HDMI cables and follow these recommended maximum lengths:

8K: Ultra High Speed HDMI 2.1 cables, up to 3 meters (10 ft)
4K@60Hz: HDMI 2.0 cables, up to 8 meters (26 ft)
4K@24Hz: HDMI 1.4 cables, up to 12 meters (39 ft)
1080P: HDMI 1.4 cables, up to 15 meters (49 ft)

High quality HDMI 2.1 cables under 30 feet are recommended in general. Exceeding these lengths or using lower-grade cables may cause signal instability or no picture.

Understanding EDID Management

The EDID DIP switch on the front panel sets the resolution and audio profile communicated to the source device. The BK-108 has 8 settings using a 3-position switch:

111 (default): Copies the EDID from the display connected to OUT 1 and sends it to the source. Recommended when all displays are the same model.
110: Forces 4K@60Hz (4:4:4) with 2.0CH audio. Use this for a consistent 4K output regardless of what displays report.
101: FRL12G 8K HDR, 2.0CH audio
100: FRL12G 8K HDR, 5.1CH audio
011: FRL12G 8K HDR, 7.1CH audio
010: FRL10G 8K HDR, 2.0CH audio
001: FRL10G 8K HDR, 5.1CH audio
000: FRL10G 8K HDR, 7.1CH audio

FRL12G supports up to 8K@60Hz; FRL10G supports up to 8K@30Hz and 4K@120Hz. After changing the DIP switch, power cycle the source device so it reads the updated EDID.

Understanding Auto Downscaling and HDR-to-SDR Conversion

The BK-108's auto downscaling works by reading the EDID of all connected displays and finding the lowest common resolution across all outputs. That minimum resolution is then applied to all eight outputs uniformly — the splitter does not individually downscale per-output.

8K source + all 8K displays: All outputs pass through 8K HDR.
8K source + mix of 8K and 4K displays: All outputs downscale to 4K SDR (the minimum across all connected displays).
4K source + mix of 4K and 1080P displays: All outputs downscale to 1080P SDR.

The automatic HDR-to-SDR conversion applies whenever the output is downscaled — HDR metadata is tone-mapped so SDR-only displays receive a compatible signal. Note that if the EDID of any display causes the output to be treated as 1080P DVI, there will be no audio on that output.

Downscaling does not work when: the source is sending 8K DSC (Display Stream Compression) format, or the source resolution is not supported by the splitter.

What Source Devices Is the BK-108 Compatible With?

The BK-108 is compatible with any HDMI 2.1 source device, including:

8K-capable PCs and laptops with HDMI 2.1 output
Gaming consoles supporting HDMI 2.1 (e.g., PlayStation 5, Xbox Series X — for 4K@120Hz with VRR/ALLM)
8K and 4K Blu-ray players
Streaming devices with HDMI 2.1 output

The BK-108 also supports VRR (Variable Refresh Rate), ALLM (Auto Low Latency Mode), QMS, QFT, and SBTM, making it particularly well suited for gaming setups. It does not support CEC.

What Displays Is the BK-108 Compatible With?

The BK-108 is compatible with any HDMI display across all eight outputs, including:

8K TVs and monitors with HDMI 2.1 input
4K TVs and monitors (HDR or SDR)
1080P TVs and monitors

You can mix 8K, 4K, and 1080P displays across the outputs. The splitter will automatically downscale all outputs to match the lowest-capability display. For a mixed environment where you want 8K outputs to receive full 8K, all connected displays should support 8K — or use the EDID DIP switch to set a fixed 8K profile so the source ignores the lower-resolution display EDIDs.

Frequently Asked Questions

Q: What is the OREI BK-108 used for?

The BK-108 is an 8K 1x8 HDMI splitter that takes one HDMI 2.1 source and distributes it to up to eight displays simultaneously. It supports 8K@60Hz, includes automatic downscaling and HDR-to-SDR conversion, and is compliant with HDMI 2.1 and HDCP 2.3.

Q: Can each output show a different source?

No. The BK-108 is a splitter with one input. All eight outputs always mirror the single HDMI input. If you need to send different sources to different displays, you would need an HDMI matrix switcher.

Q: My setup has a mix of 8K and 4K displays. Will the 8K displays still get 8K?

Not automatically. The splitter's auto downscaling selects the minimum resolution across all connected displays and applies it to all outputs. If any display reports only 4K capability, all eight outputs will downscale to 4K. To send 8K to the 8K displays, set the EDID DIP switch to a fixed 8K profile so the source outputs 8K regardless of what the other displays report.

Q: What is HDR to SDR conversion and when does it happen?

When the BK-108 downscales the signal (e.g., from 8K HDR to 4K SDR), it automatically converts the HDR metadata to SDR so that displays without HDR support receive a correctly formatted picture. This conversion is applied across all outputs whenever downscaling occurs.

Q: Does the BK-108 support CEC?

No. The BK-108 does not support CEC. You cannot use a single TV remote to control power or volume across all connected displays through this splitter.

Q: Does the BK-108 support Dolby Atmos and DTS:X?

Yes. The BK-108 passes through all HDMI audio formats to the connected displays via HDMI, including Dolby TrueHD, Dolby Atmos, DTS-HD Master Audio, and DTS:X. There is no separate optical or analog audio output.

Q: What cables do I need for 8K?

Use Ultra High Speed HDMI 2.1 certified cables no longer than 3 meters (10 ft) for 8K signals. For 4K@60Hz, HDMI 2.0 cables up to 8 meters work. High quality HDMI 2.1 cables under 30 feet are recommended in general.

Q: I am not getting any output from the splitter. What should I try?

Check that all HDMI cables are fully seated. Try swapping cables for shorter, higher-quality ones. Verify that the IN and OUT LEDs on the front panel are lit. Try setting the source to a lower resolution. Also try a different EDID setting on the front panel DIP switch, then power cycle the source.

Q: Can I use the BK-108 to extend my PC display across multiple monitors showing different content?

No. The BK-108 mirrors the source to all eight outputs — all displays show the same content. It does not support display extension or independent content per output.