HDMI ARC vs Optical: Which Should You Use? (2026)
Short answer up front: if your TV and soundbar both have it, HDMI eARC is the one to use — it’s the only one of the three that carries lossless, object-based Dolby Atmos and lets one remote run everything. Optical (Toslink) is the dependable fallback for older gear, ground-loop hum, or a flaky HDMI handshake — but it cannot carry Atmos. Here’s the honest, fully cited breakdown.
The real answer (in two sentences)
Use HDMI eARC if your TV and soundbar both have it — it’s the only one of the three that carries lossless, object-based audio (true Dolby Atmos via Dolby TrueHD, plus DTS:HD Master Audio and DTS:X) and lets one remote control volume and power over a single cable. Use plain HDMI ARC if your gear is ARC-only — you still get one-remote control and compressed surround, including the lossy (Dolby Digital Plus) version of Atmos that streaming services send. Use optical (Toslink) as the reliable fallback — for older gear without ARC, when an HDMI handshake or CEC link keeps dropping, or when you have ground-loop hum to kill — but accept that optical tops out at compressed 5.1 (Dolby Digital / DTS) or 2.0 PCM and cannot carry Atmos or any lossless format.
Put even more simply: eARC for Atmos/lossless + one remote; ARC if that’s all you have; optical as the dependable 5.1 backup for older gear or hum. The qualitative ranking — optical < ARC < eARC — is unanimous across the sources below. Crutchfield puts it plainly: “If Dolby Atmos is important to you, eARC… is the best choice” (Crutchfield), and RTINGS notes HDMI is “the better connection if you have the option” (RTINGS).
ARC vs eARC vs Optical, at a glance
The single most-misunderstood fact on this page: optical cannot carry Dolby Atmos or any lossless multichannel audio — full stop. It’s limited to compressed Dolby Digital / DTS 5.1 and 2-channel PCM; eARC is the only one of the three with the bandwidth for true (lossless TrueHD) Atmos. Every cell below cites a named source.
| What it carries / does | Optical (Toslink) | HDMI ARC | HDMI eARC |
|---|---|---|---|
| Stereo / 2.0 PCM | ✅ Yes | ✅ Yes | ✅ Yes |
| Compressed surround (Dolby Digital, DTS) 5.1 | ✅ Yes (its ceiling) | ✅ Yes | ✅ Yes |
| Uncompressed multichannel PCM (5.1 / 7.1) | ❌ No | ⚠️ Limited (5.1 only) | ✅ Yes (5.1 & 7.1) |
| Dolby Atmos — compressed (Dolby Digital Plus / streaming) | ❌ No | ✅ Yes (lossy DD+) | ✅ Yes |
| Dolby Atmos — lossless (Dolby TrueHD, e.g. Blu-ray) | ❌ No | ❌ No | ✅ Yes |
| Dolby TrueHD / DTS:HD Master Audio / DTS:X | ❌ No | ❌ No | ✅ Yes |
| Bandwidth (reported by sources, not TPA-measured) | low (compressed only) | ~1 Mbps | ~37 Mbps |
| Max channels | 5.1 (compressed) | 5.1 | up to 7.1 uncompressed |
| One-remote control (TV remote → volume/power, via HDMI-CEC) | ❌ No (separate setup) | ✅ Yes | ✅ Yes |
| Galvanic isolation — kills ground-loop hum | ✅ Yes (fiber, no shared ground) | ❌ No (copper) | ❌ No (copper) |
| Immune to EMI / RFI | ✅ Yes (light, not electrical) | ⚠️ Less so | ⚠️ Less so |
| Typical max cable run | ~5 m safe, ~10 m limit (plastic fiber) | longer (copper) | longer (copper) |
| Device availability | Very wide (incl. older gear — the universal fallback) | Wide (most TVs/bars last decade) | Modern gear (both ends must support it) |
Sources for this table: format/channel support & CEC — Cable Matters (“HDMI ARC vs. Optical”), Crutchfield (“Best Dolby Atmos sound bars”), Sonos (“Beginner’s Guide to HDMI, HDMI ARC, and eARC”), RTINGS (“Optical vs. HDMI”); bandwidth figures (~1 Mbps ARC / ~37 Mbps eARC) reported by TESmart; galvanic isolation / EMI — XDA, VCELink; cable length — TOSLINK (Wikipedia), ShowMeCables; one-remote / CEC — OREI Support. Bandwidth figures are presented as reported by those sources, not as a TheProductAnalyst.com measurement. Full list at the foot of the page.
What each connection actually is
Optical (Toslink) is a one-way fiber-optic audio cable. It carries compressed surround — Dolby Digital and DTS up to 5.1 channels — and 2-channel stereo PCM, and that’s its ceiling. As RTINGS puts it, optical cables “provide surround sound up to 5.1 channels and support Dolby Digital, DTS, and Stereo… (also called Toslink) do not support Dolby Atmos signals” (RTINGS). Crutchfield adds that optical “has a lower bandwidth than more recent versions of HDMI, which means there are some high-bandwidth audio formats, like Dolby Atmos or DTS:X, that you can’t pass with it” (Crutchfield). Cable Matters is blunt that optical is “limited to… Dolby Digital and DTS,” does not support “Dolby Atmos because they lack the bandwidth,” and cannot do uncompressed surround (Cable Matters).
HDMI ARC (Audio Return Channel) sends audio back from the TV to a soundbar or receiver over a single HDMI cable, and adds two-way control. It carries compressed surround plus the lossy (streaming) version of Dolby Atmos — but not the lossless one. Crutchfield: “ARC has a lower bandwidth, which prevents it from passing an uncompressed Dolby Atmos signal. But… most streaming services use a compressed or ‘lossy’ version of Dolby Atmos, which ARC will work with” (Crutchfield). Sonos confirms the dividing line: “though most Dolby Atmos audio can be played through HDMI ARC, you’ll need HDMI eARC to play lossless Dolby Atmos audio using the Dolby TrueHD codec” (Sonos). TESmart frames the same split — ARC supports Atmos “in compressed Dolby Digital Plus form… For lossless Dolby TrueHD-based Atmos, eARC is usually required” (TESmart).
HDMI eARC (enhanced Audio Return Channel) is the high-bandwidth upgrade and the only connection here that carries the full lossless, object-based stack: true Dolby Atmos via Dolby TrueHD, DTS:HD Master Audio, and DTS:X. Crutchfield: eARC “has a higher bandwidth and can pass uncompressed multi-channel audio formats like Dolby Atmos and DTS:X” (Crutchfield). Cable Matters lists eARC support for “Dolby TrueHD and DTS HD Master Audio,” “Dolby Atmos” and “DTS:X,” plus “uncompressed PCM audio,” and notes “eARC offers support for uncompressed 7.1 surround sound” (Cable Matters). The bandwidth headroom that makes this possible is reported by TESmart as “up to 37 Mbps, enough to deliver uncompressed 5.1 or 7.1 PCM, Dolby TrueHD, and DTS-HD Master Audio” (TESmart) — versus roughly 1 Mbps for plain ARC.
The two things HDMI gives you that optical can’t — and the one thing optical gives you that HDMI can’t
One remote (HDMI-CEC). ARC and eARC carry HDMI-CEC, so your TV remote can control the soundbar’s volume and power over the same cable. Cable Matters notes “HDMI devices can communicate and control each other through the HDMI port” (CEC); optical has no two-way control (Cable Matters). OREI is explicit that with optical, “the TV remote will control the soundbar… only if it’s connected to the TV with HDMI and CEC is turned on” — i.e., optical alone won’t pass remote control (OREI).
Optical’s real upside: galvanic isolation and EMI immunity. Because optical is light, not electricity, there’s no shared electrical ground between your source and your speakers. XDA explains that with Toslink “there is no electrical contact between your source and your speakers,” which “severs the loop and kills the hum” (XDA). VCELink adds that “the optical cable is invulnerable to EMI… whereas HDMI ARC has no strong resistance to electromagnetic interference” (VCELink). That’s exactly why optical is the go-to fix for ground-loop hum (background: epanorama).
Cable length. Plastic Toslink is practically limited to about 5 m (safe) to 10 m (max) before attenuation degrades the signal — per the TOSLINK reference, plastic optical fiber is “frequently no longer than 5 m… with a maximum length of 10 m” (Wikipedia/TOSLINK; ShowMeCables). HDMI’s copper runs longer, so for very long cable routes copper HDMI is the safer bet.
Which should you use — a quick decision guide
Modern soundbar/AVR + a TV with an eARC port → use HDMI eARC. It’s the only link that passes true lossless/object-based Atmos (TrueHD), DTS:HD Master Audio and DTS:X, plus one-remote control over a single cable. Just check the TV’s HDMI port is labeled eARC, not only ARC (Crutchfield; Cable Matters).
Your TV/soundbar are ARC-only (no eARC) → use HDMI ARC. You still get one-remote (CEC) control and compressed surround, including the streaming (Dolby Digital Plus) version of Atmos that Netflix, Disney+ and the like send. You only lose the lossless Blu-ray-grade Atmos/TrueHD layer (Crutchfield; Sonos).
Older TV/soundbar with no ARC at all, or you only care about 5.1 → use optical. Optical cleanly carries Dolby Digital / DTS 5.1 and stereo PCM and runs on a huge installed base of older gear. For movie and TV 5.1 with no Atmos ambitions, you won’t hear a downgrade (RTINGS; Cable Matters).
You have ground-loop hum, a buzz, or a flaky HDMI/CEC handshake → use optical. Because optical is light (no shared electrical ground), it breaks ground loops and ignores EMI — the go-to fix when an HDMI connection introduces hum or CEC keeps misbehaving, such as devices toggling inputs or fighting over volume (XDA; VCELink).
Rule of thumb: Want Atmos or one remote? Use HDMI — eARC if you can, ARC if you can’t. Want a dead-simple, hum-proof 5.1 link on older gear? Use optical.
Common gotchas (this is where setups go wrong)
1. “I have eARC” — but only on one device. eARC must be supported on both the TV and the soundbar/AVR, on the specifically labeled eARC port. If one end is ARC-only, the whole link runs as ARC — no lossless Atmos (Crutchfield; Cable Matters).
2. The “Atmos over optical” myth. Optical cannot carry Dolby Atmos in any form — not even the compressed/streaming version. If a setup guide tells you to run Atmos over Toslink, it’s wrong. Optical’s hard ceiling is compressed Dolby Digital / DTS 5.1 and 2.0 PCM (RTINGS; Crutchfield; Cable Matters).
3. Use a proper HDMI cable for eARC. eARC sends audio back through the cable’s Ethernet channel, so use a cable certified “High Speed with Ethernet” or “Ultra High Speed” (short runs keep it simplest), with both devices HEC-compatible. A no-Ethernet or very cheap cable can cause eARC dropouts (HDMI.org-sourced guidance; Eaton HDMI buying guide).
4. You have to turn CEC on — and it’s renamed on every brand. One-remote control needs HDMI-CEC enabled in the TV’s settings, and every maker brands it differently: Samsung “Anynet+,” LG “SimpLink,” Sony “BRAVIA Sync,” Vizio “CEC,” and so on. If your TV remote won’t change soundbar volume over ARC, CEC is almost always switched off (OREI; Roku).
5. CEC can misbehave — and that’s exactly when optical wins. CEC sometimes causes inputs to switch on their own or volume conflicts; if it’s fighting you, an optical run (audio only, no control handshake) is the stable fallback (OREI).
6. Remember the full Atmos chain. For Atmos to actually play, every link must support it: the source content must be Atmos, the TV must pass it through, the soundbar/AVR must decode it, and you must use the ARC/eARC port (lossless Atmos needs eARC). One weak link and you fall back to plain surround (TESmart).
Got the connection sorted? Here’s what to plug into it
This page is about the cable; the next step is the gear that makes the most of it. A few natural pairings:
- 🔊 Want the eARC payoff — true Dolby Atmos? Every pick here needs an eARC link for lossless Atmos → our best Dolby Atmos soundbars
- 🎬 Going for discrete multichannel with a receiver? This is where eARC vs optical matters most → our best surround sound systems
- 💸 On the optical/ARC fallback (older or budget gear)? → our best budget home theater systems
- 📡 Want to skip cable hassle altogether? → our best wireless home theater systems
One practical tip worth repeating: if you want lossless Atmos, confirm both your TV and soundbar list an eARC port (not just ARC), and run a High-Speed-with-Ethernet HDMI cable between them.
Frequently asked questions
- Can optical carry Dolby Atmos?
- No. Optical (Toslink) cannot carry Dolby Atmos in any form — not even the compressed streaming version. Its hard ceiling is compressed Dolby Digital / DTS 5.1 and 2-channel PCM; it lacks the bandwidth for object-based or lossless audio (RTINGS; Crutchfield; Cable Matters). For any Atmos, you need HDMI ARC (streaming Atmos) or eARC (lossless Atmos).
- Is HDMI ARC better than optical for a soundbar?
- Generally yes. ARC carries everything optical does plus the streaming version of Dolby Atmos, and it adds one-remote (HDMI-CEC) control over the same single cable — RTINGS calls HDMI “the better connection if you have the option.” The main reasons to prefer optical are older gear without ARC, a long cable run, or ground-loop hum, where optical’s galvanic isolation is the fix (RTINGS; Cable Matters; XDA).
- Do I need eARC for Dolby Atmos?
- It depends which Atmos. For the lossless Atmos on Blu-ray (Dolby TrueHD), yes — that needs eARC. For the compressed Atmos that streaming services send (Dolby Digital Plus), plain HDMI ARC is enough. Sonos puts it directly: “you’ll need HDMI eARC to play lossless Dolby Atmos audio using the Dolby TrueHD codec” (Sonos; Crutchfield).
- What’s the difference between ARC and eARC?
- Bandwidth, and therefore formats. Plain ARC (reported ~1 Mbps by TESmart) carries compressed surround and streaming Atmos. eARC (reported ~37 Mbps by TESmart) has far more headroom and adds lossless and uncompressed formats — Dolby TrueHD Atmos, DTS:HD Master Audio, DTS:X, and uncompressed 5.1/7.1 PCM. Both carry HDMI-CEC one-remote control (TESmart; Cable Matters; Crutchfield).
- Why is there no sound over my HDMI ARC connection?
- Two usual culprits. First, HDMI-CEC may be off — enable it in the TV settings (it’s branded Anynet+, SimpLink, BRAVIA Sync, etc.) so the link negotiates. Second, the cable: eARC in particular wants a “High Speed with Ethernet” or “Ultra High Speed” HDMI cable, and a very cheap one can drop out. Make sure you’re using the TV’s labeled ARC/eARC port too (OREI; Roku; Eaton).
- Does optical support 5.1 surround?
- Yes — optical carries compressed Dolby Digital and DTS up to 5.1 channels, plus 2.0 stereo PCM. What it can’t do is uncompressed multichannel, Atmos, or any lossless format. For plain 5.1 movie and TV audio, optical is perfectly fine (RTINGS; Cable Matters).