Optical Audio vs HDMI ARC

If you are connecting an older receiver, soundbar, or powered speaker system to a TV, the practical answer is usually:

• Choose optical audio when your audio equipment has an optical input but no HDMI ARC input.
• Choose HDMI ARC when both the TV and audio device have compatible ARC ports and you want simpler volume control through one remote.
• Do not choose based on the shape of the port alone. The label, supported standard, and device settings matter.

Optical is often the safer connection for older gear. HDMI ARC is usually more convenient and may support more audio formats, but it depends on capabilities on both ends of the connection.

Optical audio and HDMI ARC in practical terms

What optical audio does

Optical audio, commonly called TOSLINK, sends digital audio through a fiber-optic cable. A TV with an optical output can send its audio to a receiver, soundbar, DAC, or other device with an optical input.

Optical is a one-way audio connection:

TV optical output → receiver or soundbar optical input

It does not normally carry video, and it does not provide the same two-way device communication as HDMI. Volume control may therefore require the audio device’s remote, unless the TV and audio system support a separate control method.

Optical is useful because it is common on older home-theater equipment and avoids many HDMI handshake problems.

What HDMI ARC does

HDMI ARC, or Audio Return Channel, allows audio to travel back through an HDMI cable from the TV to a soundbar or receiver. It uses a specific HDMI port on each device:

TV HDMI port labeled ARC/eARC ↔ receiver or soundbar HDMI ARC/eARC port

The same connection can also support device-control features through HDMI-CEC. Depending on the equipment, this can let you:

• Control volume with the TV remote
• Turn connected equipment on or off automatically
• Switch inputs more conveniently
• Send audio from the TV’s built-in apps to the sound system

ARC is not the same as “any HDMI port.” Both devices need the appropriate ARC capability, and the cable must be connected to the labeled ports.

Optical vs HDMI ARC: the main differences

Consideration	Optical audio	HDMI ARC
Connection type	Dedicated digital audio cable	HDMI cable using ARC-enabled ports
Required TV port	Optical audio output	HDMI port labeled ARC or eARC
Required audio-device port	Optical input	HDMI ARC or eARC input/output
Audio direction	Primarily one-way	Audio return over HDMI
TV remote volume control	Often limited or unavailable	Commonly supported through HDMI-CEC
Video support	No	HDMI connection may also handle video, depending on the setup
Older equipment compatibility	Often strong	Requires compatible ARC hardware
Audio-format support	More limited	Depends on ARC/eARC and both devices
Common failure point	Wrong output setting or missing optical input	Wrong HDMI port, CEC, ARC, or handshake settings

The table is a starting point, not a guarantee. A port’s physical presence does not tell you every feature it supports.

Which audio formats can each connection handle?

The exact result depends on the TV, source app or device, receiver, soundbar, and selected output setting.

Optical audio limitations

Optical is generally suitable for:

• Stereo PCM
• Dolby Digital or similar compressed surround formats when supported by both devices
• Basic TV and streaming audio setups

Optical usually does not provide the bandwidth required for newer, higher-data-rate formats such as lossless surround audio. If you need advanced surround formats, check the manuals for both devices rather than assuming optical will support them.

A TV may also convert audio to a compatible format before sending it through optical. For example, setting the TV to PCM can improve compatibility with older equipment, but it may reduce multichannel output to stereo.

HDMI ARC capabilities

HDMI ARC can support more audio formats than optical in some systems, but the capabilities vary by implementation. eARC is a newer standard with substantially greater audio bandwidth than standard ARC and is intended for higher-quality formats.

Do not assume that:

• An HDMI 2.1 port automatically means eARC
• A TV with eARC will make an older receiver support eARC
• A soundbar with an HDMI port supports ARC
• Every app or source sends the same audio format

For an older receiver or soundbar, standard ARC may be enough for compressed surround audio and TV-app sound. If you require a specific format, verify that the TV and audio device both list it as supported.

Required capabilities: source and sink

In this connection, the source sends audio and the sink receives it.

For TV audio:

• The TV is the source when sending sound to a receiver or soundbar.
• The receiver or soundbar is the sink.

Optical connection requirements

You need:

1. A TV with a working optical audio output
2. An audio device with an optical input
3. A compatible optical cable
4. A TV audio-output setting that matches the audio device

Check the direction of the ports. A device labeled optical input cannot send audio to the TV, and a device labeled optical output is not the receiving end.

HDMI ARC connection requirements

You need:

1. A TV HDMI port labeled ARC or eARC
2. A soundbar or receiver HDMI port labeled ARC or eARC
3. An HDMI cable connecting those specific ports
4. ARC and HDMI-CEC enabled where required
5. Audio-output settings compatible with the receiving device

An ordinary HDMI input on the TV is not automatically an ARC port. Likewise, an HDMI port on a receiver may be intended only for video input or output and may not accept returned TV audio.

Port presence is not the same as feature support

This is one of the most important buying checks.

A TV may have HDMI but not HDMI ARC

Look for labels such as:

• HDMI ARC
• HDMI eARC
• HDMI IN 1 (ARC)
• HDMI OUT (TV-ARC) on a soundbar or receiver

If the port is not labeled and the specifications do not mention ARC or eARC, do not assume it supports audio return.

A TV may have optical but not every optical feature

An optical port usually indicates a digital audio output, but it does not guarantee support for every surround format. The TV’s manual or audio settings should identify available output modes.

HDMI version is not enough

ARC and eARC are separate feature considerations from general HDMI version numbering. A TV can have newer HDMI ports without providing the exact audio-return feature you need, while a device with an older HDMI implementation may still support standard ARC.

Check the individual port specification instead of relying only on the TV’s headline HDMI version.

Common compatibility traps

Connecting to the wrong HDMI port

For ARC, connect the cable to the TV port specifically labeled ARC or eARC and to the audio device’s ARC/eARC port. Connecting to another HDMI port may provide video but no TV audio return.

HDMI-CEC is disabled

ARC commonly relies on HDMI-CEC for device discovery and control. CEC may have a manufacturer-specific name in the settings menu.

If ARC does not work, check that HDMI-CEC is enabled on both devices. CEC can also create unwanted behavior, such as devices switching inputs or turning on together. If those problems occur, try a power reset and review the CEC settings on each device.

eARC and ARC are being treated as identical

eARC is not simply a label for any HDMI audio return connection. It adds higher-bandwidth capabilities, but the TV and audio device must both support the required standard. A mismatch may cause the system to fall back to standard ARC or to a more limited format.

The receiver has HDMI, but not HDMI ARC

Many older receivers have HDMI inputs and outputs for video switching but do not accept audio returned from the TV. Check for a port labeled ARC or a manual reference to Audio Return Channel.

If the receiver lacks ARC but has an optical input, optical may be the straightforward solution.

The TV is outputting an unsupported format

If you get silence, intermittent sound, or stereo when you expected surround, the TV may be sending a format the receiving device cannot decode.

Try these settings in order:

1. PCM for maximum basic compatibility
2. Auto or a compatible compressed format if the receiver supports it
3. Passthrough only when the receiving device is known to support the incoming formats

The exact names vary by TV brand. Passthrough can preserve more of the original signal, but it can also expose compatibility problems.

Using an optical cable in the wrong direction

Optical cables may look reversible, but the ports are not. The TV must have an optical output, and the audio device must have an optical input.

Remove any protective caps from the cable ends before connecting. Do not force the connector; align it with the port.

Expecting TV remote volume control over optical

Optical carries audio but generally does not provide the same control channel as HDMI-CEC. Depending on the equipment, you may need the receiver or soundbar remote, use a programmable universal remote, or rely on a device-specific control feature.

If one-remote volume control matters, HDMI ARC is usually the better option when it works reliably with your equipment.

Assuming every TV app behaves the same way

Built-in streaming apps, live TV, HDMI-connected devices, and game consoles can produce different audio formats. A connection that works with one source may still fail with another if the TV is passing through an unsupported format.

Test the actual sources you plan to use.

Which should you choose?

Choose optical when:

• Your receiver or soundbar has optical input but no ARC input
• You want a simple, isolated audio connection
• Your system uses stereo or basic compressed surround
• HDMI-CEC or ARC has caused repeated handshake problems
• You do not need TV-remote volume control through the audio cable

Optical is often the least complicated path for older audio equipment, provided the TV has an optical output.

Choose HDMI ARC when:

• Both devices have labeled ARC or eARC ports
• You want TV-remote volume control
• You use built-in TV apps and want their audio sent to the sound system
• Your receiver or soundbar supports the audio formats you plan to use
• You want fewer cables between the TV and audio system

ARC is generally the more convenient choice, but it requires more careful compatibility checking.

Prefer eARC when both devices support it

If the TV and audio device both support eARC and you need the formats or bandwidth eARC provides, use eARC. If only one device supports eARC, the system’s usable features may be limited by the other device.

For an older audio device, standard ARC or optical may be more practical than buying around an eARC feature it cannot use.

Connection checklist

Before buying a TV or cable, verify the following:

If you plan to use optical

• [ ] The TV has an optical audio output
• [ ] The receiver or soundbar has an optical audio input
• [ ] The cable reaches without sharp bends or strain
• [ ] The TV’s digital-audio setting supports the receiver
• [ ] You understand whether volume will require the audio device’s remote
• [ ] The required audio format is supported over optical

If you plan to use HDMI ARC

• [ ] The TV has a port labeled HDMI ARC or eARC
• [ ] The receiver or soundbar has a matching ARC or eARC port
• [ ] The cable is connected to those labeled ports
• [ ] HDMI-CEC is enabled if required
• [ ] ARC or eARC is enabled in the TV’s audio settings if required
• [ ] The receiver supports the formats the TV will send
• [ ] You have a fallback setting, such as PCM, if passthrough does not work

Before choosing a new TV

Record the exact audio connections on your current equipment:

• Audio device brand and model
• Optical input present: yes or no
• HDMI ARC/eARC input present: yes or no
• Required audio formats
• Whether TV-remote volume control is important
• Which external sources need to pass through the TV

Then compare those requirements with the TV’s individual port specifications. When you are ready to compare models, Browse TVs and check the connectivity details against this checklist.