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HDMI audio extractor: optical, RCA and eARC
An HDMI audio extractor separates the sound from an HDMI signal so it can be sent to an amplifier, soundbar, active headphones or speaker system that has no compatible HDMI input. It is a useful solution when the source and the screen work well together, but the audio equipment only accepts Toslink, coaxial, RCA or 3.5 mm jack.
Not every extractor works with every signal. Before choosing one, you need to identify resolution, refresh rate, HDR, HDCP, audio format, the output you need and whether the sound comes from an external source or from the TV's own apps. The word "extractor" does not automatically mean ARC or eARC.
What an extractor does
The source goes in over HDMI. The extractor passes the video signal through its HDMI output to the screen and, at the same time, delivers audio over one or more connections. An HDMI audio extractor with 4K 60 Hz and digital and analogue outputs can cover modern installations when its formats match the source, the screen and the receiver.
The extractor does not improve the quality of the source, nor does it turn any multichannel format into perfect stereo. Some let you select EDID or audio mode; others simply pass on whatever they receive. Read the datasheet and the switch positions before connecting.
Toslink, coaxial, RCA or 3.5 mm jack
| Output | Signal | Typical use | Key limitation |
|---|---|---|---|
| Toslink optical | Digital | Soundbar, DAC, AV receiver | Does not carry all modern formats |
| Coaxial S/PDIF | Digital | DAC or receiver | Requires a compatible coaxial input |
| RCA L/R | Analogue stereo | Traditional amplifier | Only two analogue channels |
| 3.5 mm jack | Analogue stereo | Active speakers, headphones | Level and noise depend on the device |
| HDMI audio only | Digital | HDMI AV receiver | Must negotiate EDID/HDCP correctly |
Toslink avoids electrical connections between devices and is practical for PCM stereo or certain compressed formats. RCA and 3.5 mm jack are suitable when the amplifier only has an analogue input. If you want high-resolution or uncompressed multichannel formats, it is usually best to keep HDMI going to a compatible receiver.
External source or TV audio
This distinction decides where the device goes. If you want to extract the sound from a console, set-top box or computer, place the extractor between the source and the screen. If you want to listen to Netflix, digital TV or apps running on the TV, the signal has to come back from the TV via ARC/eARC, optical output or analogue output.
A standard HDMI extractor connected to a TV input does not automatically receive the internal audio from its apps. For that, the TV and the device must support ARC or eARC, and the connection must be made to the labelled port. The TV's optical output may also be enough if the required format allows it.
ARC and eARC are not the same
ARC uses an audio return channel within HDMI. eARC expands capacity and compatibility with higher-bandwidth formats. A product mentioning ARC does not confirm eARC. Check which function the extractor supports, which TV port offers it and which format you want to carry.
Enable CEC and ARC/eARC in the menus when the manufacturer requires it. Brand names for these features vary. If it does not work, try PCM stereo first to reduce variables, then move on to multichannel formats.
Video: the extractor is part of the chain
Even if you buy it for the audio, the whole picture passes through it. It must support the source's resolution, refresh rate, HDR, colour depth and HDCP. For a console at 4K 120 Hz, a 4K 60 Hz extractor becomes the bottleneck and can prevent 120 Hz mode. For a 4K 60 Hz player, also check HDR and HDCP.
In the collection of HDMI accessories, cables and adapters you can complete each run, but use cables that match the format. Keep test runs short and add length only once everything is working.
Decision guide
- Console or player to a monitor without speakers: extractor between source and monitor; analogue output to active speakers.
- TV with optical output to an older amplifier: you may not need an extractor; use Toslink if both support it.
- TV apps to HDMI equipment: you need compatible ARC/eARC, not just extraction from an external source.
- Modern AV receiver with HDMI: it is usually better to connect the source to the receiver and the receiver to the TV.
- 4K 120 Hz console: look for specific 4K120 video pass-through or use eARC from the TV.
- RCA stereo amplifier: confirm conversion to PCM stereo and a variable or fixed analogue output.
EDID and audio formats
EDID tells the source which video and audio the destination supports. An extractor may offer selectors such as 2CH, 5.1CH or PASS. In 2CH it usually requests PCM stereo; in 5.1 it may advertise S/PDIF-compatible formats; PASS tries to respect the HDMI destination. Exact labels depend on the model.
If you select 5.1 and the analogue amplifier only receives stereo, you may lose dialogue or hear nothing at all. For RCA or 3.5 mm jack, set the source to PCM stereo unless the extractor specifies particular decoding. Do not confuse "extracting" with "decoding": separating a digital stream does not mean converting Dolby or DTS to multichannel analogue.
Step-by-step installation
- Switch off all devices.
- Connect the source to the extractor's HDMI IN.
- Connect HDMI OUT to the screen.
- Connect Toslink, coaxial, RCA or 3.5 mm jack to the audio equipment.
- Power the extractor from the specified source.
- Select the appropriate EDID mode, starting with PCM 2CH if in doubt.
- Switch on the screen and audio first, then the source.
- Check picture and sound with known content.
- Enable HDR or advanced formats one at a time.
If it fails, test the source directly on the screen and lower the resolution. Change one element at a time. This sequence separates a format problem from a faulty cable.
Common mistakes
- Buying a 4K30 extractor for a 4K60 signal.
- Expecting audio from the TV's apps without ARC/eARC.
- Sending Dolby to an RCA output that expects PCM.
- Confusing the TV's optical output with an input.
- Using a Toslink cable with the protective caps still on.
- Ignoring HDCP when a black screen appears while streaming.
- Connecting the extractor the wrong way round.
- Powering it from an unstable USB port.
- Assuming ARC includes eARC.
Practical example
A console is connected to a 4K monitor without speakers and to a pair of active speakers with RCA input. The extractor must accept 4K at the refresh rate in use and provide an analogue stereo output. Set the console to PCM stereo, connect the monitor to HDMI OUT and the speakers to RCA. If you later enable HDR, check that the video pass-through supports it as well.
Another case: you want to hear a smart TV's apps through an older amplifier. An extractor placed between a set-top box and the TV will only capture that set-top box. For the TV's apps, use its optical output or a compatible ARC/eARC adapter connected to the correct port.
Frequently asked questions
Does an HDMI extractor add latency?
A suitable model usually adds minimal delay, but the conversion, the TV and the audio system's processing also play a part. Use lip-sync adjustment if you notice a delay.
Does Toslink carry Dolby Atmos?
Toslink does not have eARC's bandwidth for high-quality Atmos formats. Some services may use compressed formats, but you need to check the source, TV and receiver.
Can I get RCA audio and keep 4K HDR?
Yes, if the extractor supports full 4K HDR pass-through and converts the audio to compatible stereo. Both capabilities must appear in the datasheet.
Do I need ARC for a console?
Not if you place the extractor directly between the console and the screen. ARC is needed when the audio has to come back from the TV.
Why is there picture but no sound?
The source may be sending a format that the chosen output does not support. Try PCM stereo, check EDID, the amplifier input and the direction of the cables.
First define where the audio comes from and where it needs to go. Then check video and formats. That order avoids buying an extractor that is technically capable but sits at the wrong point in the installation.