ARC vs eARC vs Optical: Which Audio Connection Is Better?

You just bought a new soundbar o AV receiver. You hooked up your 4K/8K TV, your PS5, your Apple TV, and your Blu-ray player. The picture looks amazing — but the sound is coming out of the TV speakers instead of your soundbar, or you’re missing Dolby Atmos y DTS:X surround sound.

The culprit is almost always the audio return connection between your TV and your audio system. To send TV audio back to your soundbar or receiver, you have three main options:

Choosing the wrong one — or using the right cable the wrong way — is the #1 reason people end up with stereo-only sound when they paid for Dolby Atmos. This guide breaks down ARC vs eARC vs optical, what each one actually supports, and which cable you need for your setup.

What Is ARC (Audio Return Channel)?

• Ancho de banda: ~1 Mbps (very limited)

• Audio formats supported: Dolby Digital 5.1, DTS 5.1, PCM stereo

• Does NOT support: Dolby TrueHD, DTS-HD MA, Dolby Atmos, DTS:X (lossless / object-based audio)

• Latencia: Slight lip-sync delay possible; requires TV audio sync adjustment

• Cable: Any standard HDMI cable (1.4 or later)

• Setup: Enable “HDMI ARC” or “CEC” on both TV and soundbar/receiver

What Is eARC (Enhanced Audio Return Channel)?

• Ancho de banda: ~37 Mbps (nearly 40x wider than ARC)

• Audio formats supported: Dolby TrueHD, DTS-HD Master Audio, Dolby Atmos, DTS:X, multichannel PCM up to 7.1.4

• Does NOT support: Essentially nothing important — eARC is future-proof for current audio

• Latencia: Much lower; automatic lip-sync (no manual delay needed)

• Cable: Ultra High Speed HDMI 2.1 cable (48Gbps) recommended; older High Speed cables may limit eARC to 18Gbps

• Setup: Enable “eARC” (not just ARC) on TV; plug into the eARC-labeled HDMI port on the TV

What Is TOSLINK / Optical (SPDIF)?

• Ancho de banda: ~3.1 Mbps (limited by the optical SPDIF standard)

• Audio formats supported: Dolby Digital 5.1, DTS 5.1, PCM stereo

• Does NOT support: Dolby TrueHD, DTS-HD MA, Dolby Atmos (over optical), DTS:X

• Latencia: No lip-sync delay, but no return-channel convenience

• Cable: TOSLINK optical fiber cable (square connector)

• Setup: Separate cable from TV “Optical Out” to soundbar “Optical In”

Important note: Some TVs can pass Dolby Atmos via Dolby Digital Plus (DD+) over optical on certain streaming apps, but this is compressed, not lossless Atmos. True lossless Atmos requires eARC.

ARC vs eARC vs Optical: The Full Comparison

Your Situation	Best Choice	Why
Modern TV + Atmos soundbar (2020+)	eARC (Ultra High Speed HDMI 2.1)	Only way to get lossless Dolby Atmos / DTS:X
Older TV + 5.1 soundbar, no Atmos	ARC o Optical	Both deliver Dolby Digital 5.1; ARC is more convenient
Older receiver with no HDMI input	Optical TOSLINK	Only option for digital surround; use with a converter if needed
PC / console direct to TV, then audio back	eARC	One cable carries both video and Atmos audio return
Long cable run (hidden in wall, >5m)	eARC + certified fiber HDMI AOC	Avoid signal loss over long distances

ARC vs eARC comes down to bandwidth: ARC carries ~1 Mbps (5.1 Dolby Digital only), while eARC carries ~37 Mbps and adds lossless Dolby Atmos, DTS:X, and automatic lip-sync. If your TV and soundbar both have eARC, always use it.

Yes. eARC vs optical (TOSLINK) is not close: eARC delivers lossless Dolby Atmos and DTS:X, while optical tops out at compressed 5.1. For any Atmos-capable soundbar or receiver, eARC is the correct choice.

For reliable eARC with 4K@120Hz or 8K@60Hz video plus Dolby Atmos audio, use a certified Ultra High Speed HDMI 2.1 cable (48Gbps). Older High Speed cables may limit eARC bandwidth.

Usually not needed. ARC/eARC already sends all TV audio to your soundbar over one cable. Optical is mainly for older devices without HDMI ARC.

90% of the time it is one of three things: (1) your TV is set to PCM output instead of Bitstream / Dolby Digital+, (2) you plugged into the wrong HDMI port (not the eARC one), or (3) your TV/soundbar is using ARC instead of eARC. Enable eARC, set audio output to Bitstream, and try again.

TOSLINK (optical) is a digital audio connection using light in a fiber cable. It supports Dolby Digital 5.1 and DTS, but not lossless Atmos. It remains useful for older TVs and AV receivers that lack HDMI ARC/eARC.