What Is the BK-EXB400R-K?

The OREI BK-EXB400R-K is an 8K@30Hz / 4K@120Hz HDMI over HDBaseT extender kit. It extends HDMI video, HDMI audio, analog audio extraction, IR control, RS-232 control, CEC, and power over a single CAT6 cable.

The kit includes one Transmitter, one Receiver, one IR Blaster cable, one IR Wideband Receiver cable, one power adapter, four 3-pin Phoenix connectors, mounting ears, screws, and a user manual. The HDMI source connects to HDMI IN on the Transmitter, the display connects to HDMI OUT on the Receiver, and CAT6 / CAT7 cable connects HDBT OUT on the Transmitter to HDBT IN on the Receiver.

The BK-EXB400R-K supports HDMI 2.1 and HDCP 2.3, with 40Gbps FRL and 18Gbps TMDS bandwidth. It supports video resolutions up to 8K@30Hz 4:4:4, 4K@120Hz, and 1080p@60Hz, along with HDR, HDR10, HDR10+, Dolby Vision, HLG, VRR, FVA, ALLM, Dolby Atmos, Dolby TrueHD, DTS-HD Master Audio, DTS:X, analog audio output on both ends, RS-232, CEC, bi-directional IR, and bi-directional PoC. It extends 8K@30Hz / 4K@120Hz up to 90m / 295ft, 4K@60Hz up to 120m / 394ft, and 1080p up to 150m / 492ft over CAT6 cable. 

The BK-EXB400R-K is useful for home theaters, gaming setups, conference rooms, classrooms, AV racks, control rooms, commercial displays, projector installations, and professional AV systems where high-bandwidth HDMI needs to be extended over long cable runs.

IMPORTANT — BK-EXB400R-K Is an 8K / 4K@120Hz HDBaseT Extender

The BK-EXB400R-K extends one HDMI source to one HDMI display.

This product is not a splitter or matrix. It extends one HDMI signal from the Transmitter to the Receiver.

IMPORTANT — Supports 8K@30Hz and 4K@120Hz

The BK-EXB400R-K supports high-resolution HDMI 2.1 video formats.

To get 8K@30Hz or 4K@120Hz, the HDMI source, display, HDMI cables, CAT cable, and EDID settings must all support the required signal.

IMPORTANT — Maximum Distance Depends on Resolution

The extender delivers stable signal transmission when used within the correct distance range.

For 8K@30Hz and 4K@120Hz, keep the CAT6 run within 90m / 295ft.

IMPORTANT — Use Direct CAT Cable Connection

Connect HDBT OUT on the Transmitter directly to HDBT IN on the Receiver using CAT6 / CAT7 cable.

Do not connect the HDBaseT cable through:

• Network switch 
• Router 
• Internet network 
• LAN switch 
• Standard Ethernet network 

This model requires a direct connection between the Transmitter and Receiver. It cannot be connected to a network switch.

IMPORTANT — Analog Audio Output Is Available on Both Ends

Both the Transmitter and Receiver include analog L/R audio output.

The analog audio output provides unbalanced audio output up to 1Vrms.

Unbalanced connection method:

Use this output for 2.0 speakers, amplifiers, powered speakers, or audio systems that need stereo analog audio.

IMPORTANT — HDMI Audio Pass-Through Supports Advanced Formats

The BK-EXB400R-K supports premium HDMI audio formats.

Supported audio formats include:

• LPCM 2.0 / 5.1 / 7.1 
• Dolby Digital 
• Dolby Digital Plus 
• Dolby TrueHD 
• Dolby Atmos 
• DTS Surround 
• DTS 96/24 
• DTS-ES 
• DTS Express 
• DTS-HD HRA 
• DTS-HD Master Audio 
• DTS:X 

The connected HDMI source, display, AVR, soundbar, or audio system must also support the selected audio format.

IMPORTANT — Bi-Directional IR Is Supported

The BK-EXB400R-K supports bi-directional IR control.

This allows IR control in both directions:

Typical source-control setup:

• Connect the IR Receiver cable to IR IN on the Receiver. 
• Place the IR Receiver near the remote display. 
• Connect the IR Blaster cable to IR OUT on the Transmitter. 
• Place the IR Blaster near the HDMI source device’s IR window. 

Typical display-control setup:

• Connect the IR Receiver cable to IR IN on the Transmitter. 
• Connect the IR Blaster cable to IR OUT on the Receiver. 
• Place the IR Blaster near the display’s IR window. 

The IR frequency range is 20kHz to 60kHz.

IMPORTANT — RS-232 Control Is Supported

The BK-EXB400R-K supports RS-232 control through 3-pin Phoenix connectors.

RS-232 can be used for:

• Display control 
• Projector control 
• Control processor integration 
• Automation systems 
• Serial command workflows 
• Professional AV installations 

IMPORTANT — CEC Is Supported

The BK-EXB400R-K supports CEC.

CEC behavior depends on the connected HDMI source, display, HDMI cable, and device settings.

If CEC does not work reliably, use IR or RS-232 control where available.

IMPORTANT — Bi-Directional PoC Is Supported

The BK-EXB400R-K supports bi-directional PoC.

Only one side needs the included 24V/1A power adapter.

If either the Transmitter or Receiver is connected to the power adapter, the other unit can receive power through the CAT cable.

IMPORTANT — EDID Management Is Included

The Transmitter includes an EDID DIP switch.

EDID options include:

Use EDID management when there is no video, wrong resolution, HDR issue, audio compatibility issue, or HDMI handshake problem.

IMPORTANT — No HDMI Loop Out Listed

The BK-EXB400R-K manual lists HDMI IN on the Transmitter and HDMI OUT on the Receiver.

It does not list HDMI loop out on the Transmitter.

If a local display is needed near the source, use an HDMI splitter before the Transmitter or choose an extender model with HDMI loop out.

Ports and Panel Layout

Step-by-Step Setup

1. Connect the HDMI source device to HDMI IN on the Transmitter. 
   Examples include a gaming console, Blu-ray player, streaming device, desktop PC, laptop, media player, HDMI matrix, or HDMI switch output. 
2. Connect HDBT OUT on the Transmitter to HDBT IN on the Receiver using CAT6 / CAT7 cable. 
3. Connect HDMI OUT on the Receiver to the TV, monitor, projector, or display. 
4. Connect the included DC 24V/1A power adapter to either the Transmitter or the Receiver. 
5. Set the EDID DIP switch based on the required video and audio format. 
6. If using analog audio extraction, connect AUDIO OUT L/R on the Transmitter or Receiver to powered speakers, amplifier, or audio system. 
7. If using source control from the display side, connect IR Receiver to Receiver IR IN and IR Blaster to Transmitter IR OUT. 
8. If using display control from the source side, connect IR Receiver to Transmitter IR IN and IR Blaster to Receiver IR OUT. 
9. If using RS-232 control, connect the RS-232 Phoenix connector to a laptop, PC, control processor, or serial device. 
10. Power on the HDMI source, display, Transmitter, Receiver, and connected audio/control devices. 
11. Check the Power LEDs, Link Signal Indicators, and Data Signal Indicators. 
12. Test video, audio, analog audio output, IR control, RS-232, CEC, and PoC operation. 

CAT Cable Requirement — Critical

Use high-quality CAT6 / CAT7 cable.

Poor CAT cable may cause:

• No video 
• Flickering 
• Black screen 
• Poor HDBaseT link 
• 8K@30Hz not working 
• 4K@120Hz not working 
• Audio dropouts 
• IR control issues 
• RS-232 issues 
• PoC power issues 

For no-video issues, the manual recommends trying another CAT cable and using shielded CAT6 cable.

HDMI Cable Requirement — Critical

Use high-quality HDMI cables rated for the resolution being used.

For 8K@30Hz or 4K@120Hz, use HDMI cables that support the required HDMI 2.1 bandwidth.

Poor HDMI cables may cause:

• No picture 
• Flickering 
• Black screen 
• 8K not working 
• 4K@120Hz not working 
• HDR issues 
• HDCP handshake issues 
• Audio dropouts 
• Display not detected 

For troubleshooting, test the HDMI source directly with the display before using the extender.

Power Requirement — Critical

The BK-EXB400R-K uses one DC 24V/1A power adapter.

Only one side normally needs power because PoC powers the other side through the CAT cable.

Understanding the Transmitter

The Transmitter is installed near the HDMI source.

It has:

• HDMI IN 
• HDBT OUT 
• AUDIO OUT L/R 
• EDID DIP switch 
• IR IN and IR OUT 
• RS-232 
• SERVICE USB-C port 
• DC 24V input 
• Power LED 
• Link Signal Indicator 
• Data Signal Indicator 

The Transmitter sends HDMI, audio, control, and power over CAT cable to the Receiver.

Understanding the Receiver

The Receiver is installed near the remote display.

It has:

• HDBT IN 
• HDMI OUT 
• AUDIO OUT L/R 
• IR IN and IR OUT 
• RS-232 
• SERVICE USB-C port 
• DC 24V input 
• Power LED 
• Link Signal Indicator 
• Data Signal Indicator 

The Receiver converts the HDBaseT signal back to HDMI and outputs video/audio to the connected display.

Understanding Analog Audio Output

The AUDIO OUT L/R port extracts analog audio from the HDMI signal.

Use it for:

• 2.0 speakers 
• Powered speakers 
• Amplifiers 
• Audio processors 
• Local audio zones 
• Display-side audio output 
• Source-side audio output 

The application diagram on page 15 shows 2.0 speakers connected to the Transmitter AUDIO OUT port while HDMI is extended to the Receiver and display.

Understanding EDID

EDID tells the HDMI source what video and audio format to output.

Use EDID when:

• There is no video 
• The source outputs the wrong resolution 
• 8K@30Hz does not work 
• 4K@120Hz does not work 
• HDR does not display correctly 
• Audio format does not pass correctly 
• A stable 1080p or 4K signal is needed for troubleshooting 

For normal use, start with EDID copy mode so the source can read the Receiver display’s EDID.

Understanding Signal Indicators

Use these indicators first when troubleshooting CAT cable connection, HDMI signal, and HDCP status.

Supported Video and Audio

The BK-EXB400R-K supports video formats including:

Supported audio formats include:

Supported Technical Specifications

What Source Devices Is the BK-EXB400R-K Compatible With?

The BK-EXB400R-K is compatible with HDMI source devices such as:

• Gaming consoles 
• Desktop PCs 
• Laptops with HDMI output 
• Graphics cards 
• Blu-ray players 
• DVD players 
• Cable boxes 
• Satellite receivers 
• Streaming devices 
• Media players 
• DVRs 
• NVRs 
• HDMI matrix outputs 
• HDMI switch outputs 
• AV receivers with HDMI output 

The source must output a supported HDMI resolution up to 8K@30Hz or 4K@120Hz.

What Displays Is the BK-EXB400R-K Compatible With?

The BK-EXB400R-K can connect to HDMI displays such as:

• 8K TVs 
• 4K@120Hz TVs 
• 4K TVs 
• Gaming monitors 
• Projectors 
• Commercial displays 
• Conference room displays 
• Classroom displays 
• Digital signage displays 
• Control room displays 
• Home theater displays 

For 8K@30Hz or 4K@120Hz, the display must support that resolution and refresh rate.

What Audio Devices Is the BK-EXB400R-K Compatible With?

The HDMI audio path and analog audio outputs can work with:

• AV receivers 
• Soundbars 
• Amplifiers 
• Powered speakers 
• 2.0 speaker systems 
• Audio processors 
• Home theater systems 
• Conference room audio systems 

Use AUDIO OUT L/R when analog stereo audio is needed from either the Transmitter side or Receiver side.

Frequently Asked Questions

Q: What is the OREI BK-EXB400R-K used for? 
A: It is used to extend HDMI video/audio, analog audio output, IR, RS-232, CEC, and power over a single CAT6 cable using HDBaseT technology.

Q: Does the BK-EXB400R-K support 8K? 
A: Yes. It supports up to 8K@30Hz 4:4:4.

Q: Does it support 4K@120Hz? 
A: Yes. It supports 4K@120Hz.

Q: Does it support 4K@60Hz? 
A: Yes. It supports 4K@60Hz.

Q: What HDMI version does it support? 
A: It supports HDMI 2.1.

Q: What HDCP version does it support? 
A: It supports HDCP 2.3.

Q: What video bandwidth does it support? 
A: It supports 40Gbps FRL and 18Gbps TMDS.

Q: Does it support HDR? 
A: Yes. It supports HDR, HDR10, HDR10+, Dolby Vision, and HLG.

Q: Does it support VRR? 
A: Yes. VRR is listed as supported.

Q: Does it support ALLM? 
A: Yes. ALLM is listed as supported.

Q: How far can it extend 8K@30Hz? 
A: It extends 8K@30Hz up to 90m / 295ft over CAT6 cable.

Q: How far can it extend 4K@120Hz? 
A: It extends 4K@120Hz up to 90m / 295ft over CAT6 cable.

Q: How far can it extend 4K@60Hz? 
A: It extends 4K@60Hz up to 120m / 394ft over CAT6 cable.

Q: How far can it extend 1080p? 
A: It extends 1080p@60Hz up to 150m / 492ft over CAT6 cable.

Q: What CAT cable should I use? 
A: Use high-quality CAT6 / CAT7 cable. For troubleshooting, the manual recommends shielded CAT6 cable.

Q: Can I connect it through a network switch? 
A: No. This model requires a direct connection between the Transmitter and Receiver.

Q: Is this AV over IP? 
A: No. It is an HDBaseT extender.

Q: Does the Transmitter have HDMI loop out? 
A: No HDMI loop output is listed for this model.

Q: Does it support analog audio output? 
A: Yes. Both the Transmitter and Receiver have analog AUDIO OUT L/R ports.

Q: What is AUDIO OUT used for? 
A: AUDIO OUT is used to extract analog stereo audio for speakers, amplifiers, or audio systems.

Q: Does it support Dolby Atmos? 
A: Yes. Dolby Atmos is listed as supported.

Q: Does it support DTS:X? 
A: Yes. DTS:X is listed as supported.

Q: What HDMI audio formats are supported? 
A: It supports LPCM 2.0 / 5.1 / 7.1, Dolby Digital, Dolby Digital Plus, Dolby TrueHD, Dolby Atmos, DTS Surround, DTS 96/24, DTS-ES, DTS Express, DTS-HD HRA, DTS-HD Master Audio, and DTS:X.

Q: Does it support IR control? 
A: Yes. It supports bi-directional IR control.

Q: What IR frequency is supported? 
A: It supports wideband IR from 20kHz to 60kHz.

Q: What is the IR receiving distance? 
A: The manual lists 0–5m at ±45° and 0–8m at ±90° between the IR Receiver and remote control.

Q: Which IR cable goes where for source control? 
A: Connect the IR Receiver to Receiver IR IN and the IR Blaster to Transmitter IR OUT.

Q: Which IR cable goes where for display control? 
A: Connect the IR Receiver to Transmitter IR IN and the IR Blaster to Receiver IR OUT.

Q: Does it support RS-232? 
A: Yes. It supports RS-232 control through 3-pin Phoenix connectors.

Q: Does it support CEC? 
A: Yes. CEC is supported.

Q: Does it support PoC? 
A: Yes. It supports bi-directional Power over Cable.

Q: Do both units need power adapters? 
A: No. Only one side needs the included 24V/1A power adapter because PoC powers the other side through CAT cable.

Q: Can the power adapter connect to either Transmitter or Receiver? 
A: Yes. Either unit can be powered, and the other unit can receive power through PoC.

Q: What power adapter does it use? 
A: It uses a DC 24V/1A power adapter.

Q: Does it support EDID management? 
A: Yes. It includes EDID DIP switch settings on the Transmitter.

Q: What is the EDID copy setting? 
A: DIP setting 1111 copies the Receiver HDMI OUT display EDID.

Q: What should I do if there is no video from the Receiver? 
A: Check the green and yellow CAT port lights on both ends, try changing the CAT cable, use shielded CAT6 cable, and try lowering the source resolution.

Q: What should I do if the Link Signal Indicator is off? 
A: Check that HDBT OUT on the Transmitter is connected directly to HDBT IN on the Receiver and confirm the CAT cable is working.

Q: What should I do if the Data Signal Indicator is off? 
A: No HDMI signal is present. Check the HDMI source, HDMI cable, source output setting, and HDMI IN connection.

Q: What should I do if the Data Signal Indicator is flashing? 
A: HDMI signal is detected without HDCP. Check source, display, and HDCP compatibility.

Q: What should I do if 8K@30Hz or 4K@120Hz does not work? 
A: Use HDMI cables that support the required bandwidth, keep CAT6 distance within 90m / 295ft, confirm the source and display support the selected resolution, and choose a compatible EDID setting.

Q: What should I do if analog audio output does not work? 
A: Check the AUDIO OUT Phoenix wiring, confirm the source is sending compatible audio, and test with PCM stereo if needed.

Q: What should I do if IR control does not work? 
A: Confirm the IR Receiver and IR Blaster cables are connected in the correct direction and that the IR Blaster is placed near the controlled device’s IR sensor.

Q: What should I do if RS-232 does not work? 
A: Check the Phoenix connector wiring, Tx / Rx / GND connection, serial settings, and connected control devices.

Q: Does the BK-EXB400R-K need external power? 
A: Yes. Connect the included DC 24V/1A power adapter to either the Transmitter or Receiver. The other unit can be powered through PoC.