The Audio Return Channel (ARC) primarily supports the audio formats traditionally passed through S/PDIF (also known as TOSLINK): Dolby Digital, DTS, and PCM audio. It is designed to handle both standard two-channel stereo and 5.1 surround sound without any difficulty.
Understanding ARC's Audio Capabilities
The ARC standard was specifically developed to streamline home theater setups by replacing dedicated digital audio outputs like S/PDIF. This design choice means that ARC inherits the audio format capabilities of its predecessor, ensuring compatibility with commonly used digital audio streams.
Here's a breakdown of the audio formats ARC supports:
- PCM (Pulse-Code Modulation) Audio: This is the uncompressed digital audio format, often referred to as "stereo" or "two-channel" audio. It's the most common format for general TV viewing and basic audio playback. ARC can transmit this cleanly.
- Dolby Digital: A widely used lossy compression format for surround sound. Dolby Digital (AC-3) is a staple for DVD, Blu-ray, and broadcast television, offering up to 5.1 channels of audio. ARC is fully compatible with this format.
- DTS (Digital Theater Systems): Another popular lossy compression format for multi-channel audio, similar to Dolby Digital. DTS is also commonly found on DVDs, Blu-rays, and some streaming services, supporting up to 5.1 channels. ARC seamlessly passes DTS audio.
Channel Support Overview
Beyond the specific formats, ARC is capable of transmitting various channel configurations to meet typical home entertainment needs:
- Two-Channel Audio: This is standard stereo sound, providing a left and right audio channel. It's perfect for everyday TV viewing, news, and music.
- 5.1 Surround Sound: This configuration includes a front left, front right, center, rear left, rear right, and a low-frequency effects (LFE) channel (subwoofer). It's the standard for immersive movie experiences, allowing for sounds to appear from various directions around the listener.
Key Audio Formats Supported by ARC
To provide a clear overview, here are the primary audio formats ARC supports:
| Audio Format | Type | Channel Support | Common Use Cases |
|---|---|---|---|
| PCM Audio | Uncompressed | 2-channel (stereo) | General TV, music, basic audio |
| Dolby Digital | Lossy Compressed | Up to 5.1 channels | Movies, TV shows, broadcast content |
| DTS | Lossy Compressed | Up to 5.1 channels | Movies, Blu-ray discs, gaming |
While ARC effectively handles these foundational audio formats for most users, it's important to note that it typically does not support advanced, high-bitrate audio formats like Dolby TrueHD, DTS-HD Master Audio, Dolby Atmos, or DTS:X. These newer, uncompressed or lossless formats usually require enhanced ARC (eARC) or a direct connection to an Audio/Video Receiver (AVR).
