HDA-939 Overview and Use Cases – OREI

What Is the HDA-939?

The OREI HDA-939 is an HDMI audio extractor with downmixing designed to split and process audio from an HDMI source or eARC TV while keeping the main audio experience intact.

It allows Dolby or DTS audio up to 7.1CH to pass through to a compatible AVR, amplifier, or soundbar using the HDMI Audio Only output, while also downmixing that same audio signal to other outputs at the same time.

The HDA-939 can downmix multi-channel audio to:

5.1CH audio through Optical or Coaxial output
2CH stereo audio through RCA L/R output

This makes it especially useful for households where one person needs to use hearing aids or a secondary audio system while the rest of the family continues using the main surround sound system.

IMPORTANT — Main Use Case: Hearing Aids + Surround Sound at the Same Time

The HDA-939 is commonly used in setups where one person needs audio through hearing aids, headphones, or a secondary audio device while the main sound system continues playing multi-channel audio.

Many hearing aids, headphone transmitters, and assistive listening devices connect through Optical, Coaxial, RCA, or 3.5mm audio and usually do not support Dolby Atmos, DTS:X, Dolby TrueHD, DTS-HD, or other multi-channel formats.

Without a downmixing device, customers often have to set the TV or source device to PCM/Stereo, which downgrades the audio experience for everyone using the main AVR or soundbar.

The HDA-939 helps solve this by allowing the main AVR or soundbar to receive the original Dolby or DTS audio through HDMI, while the hearing aid transmitter or secondary audio device receives a compatible downmixed signal through Optical, Coaxial, or RCA.

IMPORTANT — HDA-939 Does NOT Work with eARC-Only Soundbars

The HDA-939 does not work with eARC-only soundbars such as:

Sonos Arc
Sonos Beam
Bose Smart Soundbar 600
Bose Smart Soundbar 900
Soundbars with only one HDMI ARC/eARC port

The HDA-939 has a normal HDMI Audio Only output. This output is designed to connect to a regular HDMI input on an AVR, amplifier, or soundbar.

It is not an eARC soundbar output.

If your soundbar or AVR only has a single HDMI port, that port is most likely ARC/eARC, and the HDA-939 will not work with it.

The HDA-939 works best with AVRs, amplifiers, or soundbars that have a normal HDMI input, not an ARC/eARC HDMI port.

IMPORTANT — HDA-939 Can Downmix Audio for Secondary Outputs

The HDA-939 can process Dolby and DTS audio and output downmixed audio through secondary ports.

It can send:

Full multi-channel audio through HDMI Audio Only output
Downmixed 5.1CH audio through Optical or Coaxial
Downmixed 2CH stereo audio through RCA L/R

This allows customers to connect both a main surround system and a secondary listening device at the same time.

For example:

HDMI Audio Only output to AVR for surround sound
Optical output to hearing aid transmitter
RCA output to powered stereo speakers or subwoofers

Ports and Panel Layout

Port / LED / Button	Location	Function
Power LED	Front panel	Red LED turns on when the device is powered
HDMI IN LED	Front panel	Lights up when an HDMI input signal is detected
HDMI OUT 1/2 LEDs	Front panel	Lights up when HDMI Output 1 or HDMI Output 2 is connected and active
PCM / Dolby / DTS / DTS-HD LEDs	Front panel	Shows the detected or decoded audio format
Audio Input LEDs	Front panel	Shows whether the HDMI source or ARC/eARC TV is selected as the Audio source
Select Button	Front panel	Selects between HDMI source or ARC/eARC audio as the audio input
HDMI IN	Rear panel	Connect an HDMI source device such as a Blu-ray player, PS5, Xbox, streaming device, or PC
HDMI Output 1	Rear panel	HDMI output to TV, projector, or monitor; supports ARC/eARC connection to TV
HDMI Output 2	Rear panel	HDMI Audio Only output for a normal HDMI input on an AVR, amplifier, or a compatible soundbar
Optical (Toslink)	Rear panel	Optical digital audio output
Coaxial	Rear panel	Coaxial digital audio output
L/R RCA	Rear panel	Downmixed analog stereo audio output
Setting DIP Switch	Rear panel	Controls downscaling, downmixing, ARC/eARC function, HDMI audio embedding, and EDID management
RS-232	Rear panel	Control port for RS-232 commands
DC 12V	Rear panel	Connect the included 12V power adapter

Step-by-Step Setup

Connect your HDMI source device, such as a Blu-ray player, streaming device, cable box, game console, or PC, to the HDMI IN port on the HDA-939.
Connect HDMI Output 1 to your TV, projector, or monitor. If your TV supports ARC/eARC and you want audio from the internal apps, connect it to the ARC/eARC port on the TV.
Connect HDMI Output 2 to a regular HDMI input on your AVR, amplifier, or soundbar.
Connect your secondary audio device:
- Use Optical or Coaxial for a hearing aid transmitter or digital audio device.
- Use RCA L/R for analog stereo speakers, amplifiers, or other stereo audio devices.
Connect the included 12V power adapter to the HDA-939.
Turn on your HDMI source, TV, AVR/soundbar, and secondary audio device.
Use the Select button to choose the audio input source. Set to ‘HDMI IN’ to extract audio from the media source and set to ‘ARC/eARC’ for audio from an ARC/eARC TV.
Set the DIP switches based on your desired audio and video behaviour.
Play content and confirm:
- Video appears on the TV.
- Main audio plays through the AVR or soundbar.
- Downmixed audio plays through the Optical, Coaxial, or RCA output.

HDMI Cable Requirement — Important

Use good-quality HDMI cables rated for 18Gbps bandwidth for stable 4K@60Hz performance.

For 4K@60Hz 4:4:4, use Premium High Speed HDMI cables.

Understanding the Audio Outputs

The HDA-939 has multiple audio outputs that can be used for different purposes.

Output	Best Used For	Audio Type
HDMI Output 2 Audio Only	AVR, amplifier, or soundbar with normal HDMI input	Multi-channel HDMI audio up to 7.1CH. Audio formats like Dolby Digital Plus, DTS-HD MA, etc.
Optical	Hearing aid transmitter, soundbar, AVR, or Amplifier	Downmixed digital audio, typically up to 5.1CH. Audio formats Like Dolby Digital, DTS 5.1.
Coaxial	Digital audio receiver or amplifier	Downmixed digital audio, typically up to 5.1CH. Audio formats Like Dolby Digital, DTS 5.1.
RCA L/R	Powered speakers, stereo amplifier, analog audio device	Downmixed 2CH stereo audio

The HDMI Audio Only output is for the main audio system. The Optical, Coaxial, and RCA outputs are useful for secondary audio devices.

What Soundbars or AVRs Is the HDA-939 Compatible With?

The HDA-939 is compatible with AVRs, amplifiers, and soundbars that have a normal HDMI input.

It is intended to connect the HDMI Audio Only output from the HDA-939 to a standard HDMI input on the audio system.

It is commonly compatible with traditional AV receivers from brands such as Denon, Marantz, Yamaha, Onkyo, Sony, Pioneer, Anthem, Arcam, and similar receiver-based systems.

The HDA-939 is not compatible with eARC-only soundbars or audio systems that only have one HDMI ARC/eARC port.

If the audio device has a normal HDMI input, it can work. If the audio device only has an HDMI ARC/eARC port, it will not work.

What Source Devices Is the HDA-939 Compatible With?

The OREI HDA-939 is compatible with HDMI source devices such as:

Blu-ray players
Streaming devices
Cable boxes
Satellite boxes
Gaming consoles
PCs
Laptops with HDMI output
Media players

The source device can send video to the display while the HDA-939 extracts and processes audio for both the main audio system and secondary audio outputs.

Frequently Asked Questions

Q: What is the OREI HDA-939 used for?
A: The HDA-939 is used to extract and downmix HDMI audio. It can send multi-channel Dolby or DTS audio to a main AVR or soundbar through HDMI while also sending downmixed audio to Optical, Coaxial, or RCA outputs.

Q: What is the main use case for the HDA-939?
A: The main use case is for households where one person uses hearing aids or a secondary audio device while the rest of the family still wants full surround sound from the main AVR or soundbar.

Q: Can the HDA-939 help with hearing aids?
A: Yes. Many hearing aid transmitters use Optical, Coaxial, RCA, or 3.5mm audio and do not support multi-channel audio. The HDA-939 can provide a downmixed audio output for hearing aids while keeping multi-channel audio active for the main AVR or soundbar.

Q: Will using the HDA-939 force my main sound system to stereo?
A: No. That is the main benefit of this product. The HDA-939 can keep Dolby or DTS audio going to the main AVR or soundbar through HDMI while separately downmixing audio for Optical, Coaxial, or RCA output.

Q: Does the HDA-939 work with Sonos Arc?
A: No. The HDA-939 does not work with Sonos Arc because Sonos Arc uses an HDMI ARC/eARC connection only. The HDA-939’s HDMI Audio Only output must connect to a normal HDMI input, not an ARC/eARC-only port.

Q: Does the HDA-939 work with Bose Smart Soundbar 600 or 900?
A: No. Bose Smart Soundbar 600 and 900 are eARC/ARC soundbars and do not have a normal HDMI input for the HDA-939’s HDMI Audio Only output.

Q: Does the HDA-939 work with eARC soundbars?
A: No. The HDA-939 does not work with eARC-only soundbars. It works with audio devices that have a normal HDMI input.

Q: My soundbar only has one HDMI port. Will the HDA-939 work?
A: Most likely no. If your soundbar only has one HDMI port, it is usually an ARC/eARC port, not a regular HDMI input. The HDA-939 requires a normal HDMI input on the soundbar, AVR, or amplifier.

Q: What audio outputs does the HDA-939 have?
A: It has HDMI Audio Only output, Optical output, Coaxial output, and RCA L/R analog output.

Q: Can Optical or Coaxial output Dolby/DTS audio?
A: Yes, Optical or Coaxial can output downmixed digital audio, typically up to 5.1CH depending on the source format, settings, and connected device.

Q: Can RCA output Dolby or DTS audio?
A: No. RCA L/R outputs 2-channel analog stereo audio only. The HDA-939 downmixes the audio to stereo for RCA output.

Q: Can I use the HDA-939 without connecting an AVR or soundbar?
A: Yes. The device can still extract audio from an HDMI input and output audio through Optical, Coaxial, or RCA without requiring an HDMI audio receiver to be connected.