Optical vs HDMI ARC
Similar audio capability for 5.1, but ARC adds remote-control passthrough on one cable while optical provides complete electrical isolation.
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Both carry sound from a television to a soundbar, and for ordinary 5.1 surround they sound the same. ARC wins on convenience: one cable instead of two, and the TV remote controls the soundbar's volume. Optical has one real advantage people forget — it is light down a fibre, so it carries no electrical connection at all and cannot pass a hum or a ground loop between your devices. If you have buzzing you cannot trace, optical often cures it.
- Verdict:
- ARC for convenience, optical when you need electrical isolation
Side by side
| Specification | Optical (TOSLINK) | HDMI ARC |
|---|---|---|
| Max audio | Compressed 5.1 | Compressed 5.1 (eARC: lossless 7.1) |
| Cables needed | Two — video and audio | One |
| Volume from TV remote | No | Yes, via CEC |
| Electrical isolation | Complete — it is light | No |
| Cable run | Fragile if bent tightly | Robust |
| Immune to ground loops | Yes | No |
The hum fix
A ground loop between a TV and an amplifier produces a mains hum that no volume setting removes. An optical link breaks the electrical path entirely, which is why it remains the first thing to try when a system buzzes.
Where ARC pulls ahead
One cable, and the television's remote controls the soundbar because CEC travels alongside the audio. With optical you keep two remotes or program a universal one. For most living rooms that convenience decides it.
Neither is the Atmos answer
Plain optical and plain ARC both top out at compressed 5.1. If lossless Atmos is the goal, the only route here is eARC — optical has no path to it at all.
Diagnosing a hum
If a system buzzes and the noise changes when you touch equipment or plug in another device, it is likely a ground loop. Swapping the audio link to optical breaks the electrical path and is the quickest test, since fibre carries no current at all.
Handling the cable
TOSLINK is a plastic fibre and it does not like tight bends. A kinked optical cable can fail intermittently or stop working entirely, and unlike copper there is no partial degradation to warn you. Keep the bend radius generous and do not crush it behind furniture.
Latency and lip sync
Either link can end up slightly out of step with the picture. eARC includes a lip-sync correction mechanism as a requirement; with optical you rely on the manual delay setting in the television or soundbar. Both are fixable, but only one fixes itself.
Check before you swap. Batteries with similar dimensions are not always interchangeable. Always verify voltage, chemistry and the requirements printed in your device manual before fitting a replacement.
Optical vs HDMI ARC: common questions
What is the difference between Optical (TOSLINK) and HDMI ARC?
Both carry sound from a television to a soundbar, and for ordinary 5.1 surround they sound the same. ARC wins on convenience: one cable instead of two, and the TV remote controls the soundbar's volume. Optical has one real advantage people forget — it is light down a fibre, so it carries no electrical connection at all and cannot pass a hum or a ground loop between your devices. If you have buzzing you cannot trace, optical often cures it.
Which should I choose, Optical (TOSLINK) or HDMI ARC?
ARC for convenience, optical when you need electrical isolation. Similar audio capability for 5.1, but ARC adds remote-control passthrough on one cable while optical provides complete electrical isolation.
Max audio — how do they compare?
Optical (TOSLINK): Compressed 5.1. HDMI ARC: Compressed 5.1 (eARC: lossless 7.1).