HDMI ARC vs. Optical Audio: Sound Matters

Last Updated: August 2, 2023By
HDMI cable on white surface 1

Sound quality can make or break your media consumption experience. Whether you’re engrossed in an epic movie, lost in the melodies of your favorite music, or immersed in the thrilling action of a video game, audio plays a crucial role.

At the heart of this sound experience lie two technologies: HDMI Audio Return Channel (ARC) and Optical Audio.

Understanding HDMI Audio Return Channel (ARC)

HDMI Audio Return Channel, often abbreviated as HDMI ARC, is a special feature found in the HDMI (High Definition Multimedia Interface) specification. It’s designed to simplify home theater systems by reducing the number of cables needed to transmit audio between devices.

The Working Mechanism of HDMI ARC

Typically, your television and audio system (like a soundbar or home theater receiver) need separate connections for video input and audio output. HDMI ARC cleverly merges these into one.

When you connect two ARC-compatible devices via an HDMI cable, the audio can ‘return’ from the TV to the audio system, hence the term Audio Return Channel. This feature enables your TV to send audio back to your sound system without the need for any additional audio cables.

The Advantages of Using HDMI ARC

Audio and Video in One Cable: HDMI ARC reduces cable clutter by transmitting audio and video signals over the same cable. This simplifies the setup process and maintains a cleaner look for your home theater system.

Control of Multiple Devices: HDMI ARC supports CEC (Consumer Electronics Control), which allows control of multiple devices from a single remote. For instance, you can adjust the volume of a soundbar using your TV remote, enhancing the convenience of operation.

Simplified Setup: The technology simplifies the audio setup, as you only need to connect one HDMI cable between your TV and your audio receiver or soundbar.

Potential for Higher Quality Audio: HDMI ARC can handle many types of audio signals, including Dolby Digital, DTS, and PCM. Depending on your setup, this can potentially result in better audio quality.

The Disadvantages of HDMI ARC

Not All Devices Support It: While HDMI ARC is becoming increasingly common, not all devices support it. You need to ensure both your TV and your audio system are ARC-compatible.

Potential for Compatibility Issues: Even among devices that support HDMI ARC, there can sometimes be compatibility issues due to varying implementations of the technology by different manufacturers.

Limitation in Supported Audio Formats: While HDMI ARC does support many audio formats, it doesn’t support the latest high-end formats like Dolby TrueHD and DTS:X. For these, you’d need to use the more advanced eARC (enhanced Audio Return Channel), provided your devices support it.

Understanding Optical Audio

Optical Audio, also known as Toslink (short for Toshiba-Link), is a method of transmitting digital audio signals from a source to an audio receiver (like a soundbar or home theater system) using optical fiber. It’s been a popular audio connection standard for several decades.

The Working Mechanism of Optical Audio

The Optical Audio cable carries a digital audio stream from devices like a Blu-Ray player, game console, or television to an audio receiver. It operates by sending pulses of light through an optical fiber inside the cable, translating these light pulses back into audio signals at the receiving end.

This unique method of transmission ensures that the audio signal remains free from electromagnetic or radio frequency interference.

The Advantages of Using Optical Audio

Consistent and Reliable Audio Quality: Because Optical Audio cables transmit signals using light, they are resistant to electrical interference. This leads to consistent and reliable audio quality.

Broad Device Compatibility: Optical Audio has been around for a while, meaning a vast number of devices support it. It’s a safe and versatile choice if you’re dealing with a mix of newer and older devices.

No Electrical Interference: Unlike traditional electrical audio cables, Optical Audio cables are immune to electrical or magnetic interference since they use light to transmit audio signals. This can be a significant advantage in environments where such interference is a problem.

The Disadvantages of Optical Audio

Separate Cables for Audio and Video: Unlike HDMI ARC, Optical Audio handles audio only. This means you’ll need separate connections for your video signals, potentially leading to more cable clutter.

No Control for Multiple Devices: Optical Audio does not support features like HDMI-CEC, meaning you can’t control multiple devices with a single remote.

Limitation in Supported Audio Formats: While Optical Audio can deliver high-quality digital audio, it doesn’t support some of the latest surround sound formats that provide the best audio quality, such as Dolby TrueHD or DTS:X. For these, you would need to use HDMI connections.

Comparing HDMI ARC and Optical Audio

Close up of black HDMI cable

To fully comprehend the capabilities and limitations of HDMI ARC and Optical Audio, it’s essential to put them side by side.

Comparing Sound Quality

When considering sound quality alone, HDMI ARC has a slight edge due to its capacity to handle more types of audio signals, including some higher quality formats. However, both HDMI ARC and Optical Audio can deliver excellent digital surround sound that will satisfy most users.

Neither of these methods should cause a loss of audio quality during transmission.

Setup Complexity

When it comes to setup complexity, HDMI ARC may be the simpler choice because it consolidates audio and video signals into a single cable. This can help minimize the number of cables and reduce clutter.

In contrast, Optical Audio requires a separate connection for audio and video, which may make the setup process a bit more complex.

Device Compatibility

In terms of device compatibility, Optical Audio has a slight advantage. It’s been around for longer and is supported by a vast array of both older and newer devices. 

HDMI ARC, while increasingly common, is not supported by all devices. You need to ensure both your TV and your audio system support HDMI ARC for it to work.

Cost Comparison

The cost of HDMI and Optical Audio cables is relatively similar, with both types available at a variety of price points. Therefore, the decision between HDMI ARC and Optical Audio should not significantly impact the overall cost of your audio setup. However, the potential reduction in the number of cables needed with HDMI ARC could lead to some savings.

Case Scenarios: When to Use HDMI ARC or Optical Audio

Deciding between HDMI ARC and Optical Audio largely depends on your specific situation and needs. Here are a few scenarios that might help clarify when to use each:

Scenario 1: A Modern Home Theater Setup

In a modern home theater setup where all your devices are HDMI ARC-compatible, it would be beneficial to use HDMI ARC. It provides a simpler and cleaner setup with one cable handling both audio and video signals.

Furthermore, the HDMI-CEC feature lets you control multiple devices using a single remote, enhancing the user experience.

Scenario 2: An Older System with Limited HDMI Ports

If you have an older system with limited HDMI ports or the devices do not support HDMI ARC, Optical Audio is a reliable choice. Even if your system is a mix of newer and older devices, Optical Audio’s broad compatibility comes in handy.

It ensures consistent audio quality and is unaffected by electrical or magnetic interference.

Scenario 3: Setup Requiring Maximum Audio Quality

For users who are audiophiles and want the maximum audio quality possible, the decision might be a bit more complicated. Neither HDMI ARC nor Optical Audio supports the latest high-resolution audio formats like Dolby TrueHD or DTS:X.

For these, you would need an eARC (enhanced Audio Return Channel) compatible system. However, if eARC is not an option, HDMI ARC generally supports a wider range of audio formats than Optical Audio. This makes it a better choice for those prioritizing sound quality, given that their equipment is compatible.


Deciding between HDMI ARC and Optical Audio isn’t a one-size-fits-all scenario, but rather a decision that depends on your unique needs and existing equipment. Both technologies provide high-quality digital audio, but they have distinct advantages and potential drawbacks.

HDMI ARC, with its ability to transmit both audio and video signals through a single cable and control multiple devices, brings simplicity and convenience to modern home theater systems. It supports a wider array of audio formats, potentially offering better sound quality, given your devices are ARC-compatible.

On the other hand, Optical Audio’s broad device compatibility, immunity to electrical interference, and consistent audio quality make it a reliable choice, particularly for older systems or environments prone to electrical noise.

Whether you choose HDMI ARC or Optical Audio, the key lies in understanding your audio system’s requirements and your preferences. By doing so, you can achieve an audio experience that suits your needs and enhances your media consumption, providing a sound experience that truly resonates.