HDA-4KMB Overview and Use Cases

What Is the HDA-4KMB?

The OREI HDA-4KMB is a 4K HDMI Audio Embedder designed to add external audio into an HDMI output signal.

It allows audio from either a 3.5mm analog stereo input or optical SPDIF input to be embedded into the HDMI output. This is useful when the HDMI video source needs to continue to the display, but the audio needs to come from a different audio source.

The HDA-4KMB supports HDMI 2.0b, HDCP 2.2 / 1.4, 18Gbps bandwidth, and video resolutions up to 4K@60Hz YUV 4:4:4. It also supports 10-bit and 12-bit color, HDR pass-through, and high-resolution HDMI audio pass-through formats including Dolby Atmos, Dolby TrueHD, DTS-HD Master Audio, and DTS:X.

The HDA-4KMB is useful for home theater systems, commercial AV installations, conference rooms, classrooms, media systems, gaming setups, and professional AV applications where external audio needs to be inserted into an HDMI signal.

IMPORTANT — HDA-4KMB Is an Audio Embedder

The HDA-4KMB embeds audio into HDMI output.

This product is not an HDMI switch, HDMI splitter, HDMI matrix, or audio extractor.

It is designed to take an HDMI video signal and embed the selected audio source into the HDMI output.

IMPORTANT — Three Audio Source Options Are Available

The rear-panel dial switch lets you select which audio source is embedded into the HDMI output.

Use the switch to choose whether the HDMI output audio should come from the original HDMI source, the optical input, or the analog line input.

IMPORTANT — Supports 4K@60Hz HDMI 2.0b Video

The HDA-4KMB supports high-bandwidth HDMI video pass-through.

To get 4K@60Hz performance, the HDMI source, HDMI display, and HDMI cables must all support 18Gbps HDMI 2.0 operation.

IMPORTANT — HDR Pass-Through Is Supported

The HDA-4KMB supports HDR pass-through.

For HDR to work, the HDMI source, display, and HDMI cables must all support the HDR format being used.

IMPORTANT — HDMI High-Resolution Audio Pass-Through Is Supported

When using HDMI audio pass-through, the HDA-4KMB supports advanced HDMI audio formats.

Use the HDMI setting on the dial switch when you want to keep audio from the original HDMI source.

IMPORTANT — Optical Audio Input Supports PCM, Dolby Digital, and DTS

The optical input can embed compatible SPDIF audio into HDMI output.

Use the Optical setting on the dial switch when audio should come from the optical SPDIF input.

The optical input does not support advanced HDMI-only formats such as Dolby TrueHD, DTS-HD Master Audio, Dolby Atmos over TrueHD, or DTS:X.

IMPORTANT — Analog Line Input Supports PCM 2.0 Stereo

The 3.5mm Line In port supports analog stereo audio.

Use the Line setting on the dial switch when audio should come from a 3.5mm stereo analog source.

IMPORTANT — HDMI Output Must Be Connected

The HDA-4KMB has a Link LED that lights when an HDMI output signal is detected.

If the Link LED does not light, check the HDMI output cable, display input, source signal, and power connection.

Ports and Panel Layout

Front Panel

Rear Panel

Step-by-Step Setup

1. Place the HDA-4KMB near the HDMI source and display.
2. Connect the HDMI source device to the HDMI In port.

Examples include a Blu-ray player, DVD player, streaming device, media player, PC, game console, or HDMI switch output.

1. Connect the HDMI Out port to the display, AV receiver, projector, monitor, or other HDMI receiving device.
2. If using analog audio embedding, connect the analog audio source to the Line In port using a 3.5mm stereo audio cable.
3. If using optical audio embedding, connect the optical audio source to the Optical In port using a TOSLINK optical cable.
4. Connect the included DC 5V/1A power adapter.
5. Power on the HDMI source, display, audio source, and HDA-4KMB.
6. Use the rear dial switch to select the audio source:
   • HDMI for original HDMI audio
   • Optical for SPDIF audio
   • Line for 3.5mm analog stereo audio
7. Confirm the Power LED is on.
8. Confirm the Link LED lights when HDMI output is detected.
9. Test video on the display.
10. Test audio from the selected audio source through the HDMI output device.

HDMI Cable Requirement — Critical

Use high-quality HDMI cables, especially for 4K@60Hz HDR video.

Poor HDMI cables may cause:

• No video
• Flickering
• Black screen
• HDR not passing correctly
• 4K60 failure
• HDCP handshake issues
• Audio dropouts
• Link LED not lighting
• Display not detecting signal

For troubleshooting, test the HDMI source directly with the display before connecting through the HDA-4KMB.

Audio Source Requirement — Critical

Select the correct audio source using the HDMI / Optical / Line dial switch.

If there is no audio from HDMI output:

• Make sure the correct audio input source is selected on the dial switch.
• Confirm the selected audio source is active.
• Confirm the audio format is supported.
• Try switching between HDMI, Optical, and Line to test each input.
• Check the HDMI output device audio settings.
• Check the source device audio settings.

Optical Audio Requirement — Critical

The Optical In port supports SPDIF audio formats only.

If optical audio does not work:

• Set the optical source to PCM, Dolby Digital, or DTS.
• Confirm the optical cable is fully inserted.
• Make sure the dial switch is set to Optical.
• Test the optical source with another optical audio device.
• Try PCM 2.0 for maximum compatibility.

Analog Line Audio Requirement — Critical

The Line In port supports standard analog stereo audio.

If analog line audio does not work:

• Make sure the dial switch is set to Line.
• Confirm the audio source is playing.
• Check the 3.5mm audio cable.
• Increase the volume on the audio source device.
• Test the audio source directly with headphones or speakers.

Power Requirement — Critical

The HDA-4KMB requires the included DC 5V/1A power adapter.

If the unit does not power on:

• Check the DC 5V power adapter.
• Confirm the outlet is working.
• Check the Power LED.
• Try power cycling the unit.

Surge protection is recommended.

Understanding the Application Example

The application diagram shows a DVD or Blu-ray player connected to the HDMI input. A PC connects to the Line In port, and an amplifier connects to the Optical In port. The HDMI output connects to a UHD TV, while the DC 5V power adapter powers the unit.

This shows the main use case: the video source passes through HDMI, while the user can choose whether HDMI, analog line, or optical audio is embedded into the HDMI output.

Supported Technical Specifications

Package Contents

What HDMI Source Devices Is the HDA-4KMB Compatible With?

The HDA-4KMB can connect to HDMI source devices such as:

• DVD players
• Blu-ray players
• Streaming devices
• Media players
• Cable boxes
• Satellite receivers
• Game consoles
• PCs
• Laptops
• HDMI switch outputs
• HDMI matrix outputs
• AV receiver HDMI outputs

For best performance, use HDMI sources set to 4K@60Hz or lower.

What Audio Source Devices Is the HDA-4KMB Compatible With?

The HDA-4KMB can embed audio from:

• Optical SPDIF audio sources
• 3.5mm analog stereo audio sources
• HDMI source audio

Compatible audio source examples include:

• PCs
• Amplifiers
• AV receivers
• Audio processors
• TVs with optical output
• Media players with optical output
• Audio devices with 3.5mm line output
• Streaming devices with HDMI audio
• Blu-ray players with HDMI audio

What Displays Is the HDA-4KMB Compatible With?

The HDA-4KMB can output HDMI to:

• 4K TVs
• UHD TVs
• HDMI monitors
• HDMI projectors
• AV receivers
• HDMI capture devices
• Commercial displays
• HDMI switch or matrix inputs

The connected display or HDMI device must support the selected video resolution and audio format.

Frequently Asked Questions

Q: What is the HDA-4KMB used for? 
A: It is used to embed external analog or optical audio into an HDMI output signal.

Q: Is the HDA-4KMB an audio embedder? 
A: Yes. It is a 4K HDMI audio embedder with 3.5mm and optical audio inputs.

Q: Does it extract audio from HDMI? 
A: Its main function is audio embedding. It does not provide a separate HDMI audio extraction output.

Q: How many HDMI inputs does it have? 
A: It has one HDMI input.

Q: How many HDMI outputs does it have? 
A: It has one HDMI output.

Q: What audio inputs does it have? 
A: It has one 3.5mm analog stereo Line In and one Optical SPDIF input.

Q: How do I choose the audio source? 
A: Use the rear dial switch to select HDMI, Optical, or Line.

Q: Does it support 4K@60Hz? 
A: Yes. It supports video resolutions up to 4K@60Hz YUV 4:4:4.

Q: What HDMI version does it support? 
A: It supports HDMI 2.0b.

Q: What HDCP version does it support? 
A: It supports HDCP 2.2 and HDCP 1.4.

Q: What video bandwidth does it support? 
A: It supports 18Gbps bandwidth.

Q: Does it support HDR? 
A: Yes. It supports HDR pass-through, including HDR10, Dolby Vision, and HLG as listed in the manual FAQ.

Q: Does it support Dolby Atmos? 
A: Yes, Dolby Atmos is supported through HDMI audio pass-through.

Q: Does it support Dolby TrueHD? 
A: Yes, Dolby TrueHD is supported through HDMI audio pass-through.

Q: Does it support DTS-HD Master Audio? 
A: Yes, DTS-HD Master Audio is supported through HDMI audio pass-through.

Q: Does it support DTS:X? 
A: Yes, DTS:X is supported through HDMI audio pass-through.

Q: Does the optical input support Dolby Atmos? 
A: No. Optical input supports LPCM 2CH, Dolby Digital 2/5.1CH, and DTS 2/5.1CH only.

Q: Does the optical input support DTS-HD or Dolby TrueHD? 
A: No. Those formats require HDMI audio pass-through.

Q: What does the 3.5mm Line In support? 
A: It supports standard PCM 2.0 stereo analog audio.

Q: Can I embed analog audio into HDMI output? 
A: Yes. Set the dial switch to Line and connect the analog source to Line In.

Q: Can I embed optical audio into HDMI output? 
A: Yes. Set the dial switch to Optical and connect the optical source to Optical In.

Q: Can I keep the original HDMI audio? 
A: Yes. Set the dial switch to HDMI.

Q: Does it support CEC bypass? 
A: Yes. The manual lists HDCP 2.2 and CEC bypass.

Q: What should I do if there is no video output? 
A: Try lowering the resolution from the media source, change the HDMI cables, or try another HDMI input on the display.

Q: What should I do if there is no audio from HDMI output? 
A: Make sure the correct audio source is selected, confirm the audio format is supported, and try switching between HDMI, Line, and Optical.

Q: Why is there no sound when using Line In? 
A: Confirm the dial switch is set to Line, check the 3.5mm audio cable, and increase the volume on the analog audio source.

Q: Why is there no sound when using Optical In? 
A: Confirm the dial switch is set to Optical, check the optical cable, and make sure the optical source is outputting LPCM 2CH, Dolby Digital, or DTS.

Q: What does the Power LED mean? 
A: It lights when the device is powered on.

Q: What does the Link LED mean? 
A: It lights when an HDMI output signal is detected.

Q: What power adapter does it use? 
A: It uses a DC 5V/1A power adapter.

Q: What is the power consumption? 
A: The manual lists power consumption as 1.25W max.

Q: Does the HDA-4KMB need external power? 
A: Yes. Connect the included DC 5V/1A power adapter.