Audio passthrough sends a supported encoded audio stream onward for a downstream device to decode, rather than decoding it into PCM in the player. This can preserve access to formats or spatial information that a receiver understands. It is not a universal quality improvement, and enabling it cannot make unsupported equipment decode a new format. Every part of the route must accept the chosen bitstream, including any television forwarding stage. A system can support passthrough for one codec while requiring local decoding or conversion for another.
Audio passthrough and Local decoding
Passthrough retains encoded audio; local decoding converts it into samples before output.
The decoder moves downstream
With local decoding, the app or device produces PCM and may perform mixing, volume control or downmixing. With passthrough, the receiver normally performs the codec decoding. The player and operating system still manage delivery and timing. Depending on the implementation, some local sound effects, processing or volume controls may behave differently when an encoded bitstream is selected.
Check the complete route
A source connected directly to a receiver has a different capability path from a source connected through a television and ARC or eARC. The television may restrict which formats it forwards. Advertised support at the final soundbar is therefore insufficient on its own. Check the input format actually reported during the problematic programme, rather than relying solely on menu selections.
Silence is useful evidence
If supported PCM output works while passthrough is silent, suspect encoded-format support, signalling or routing before changing the network. Compare one codec at a time and retain the original settings. Conversely, sound in passthrough does not prove local decoding works. Both paths are valid configurations when their capabilities and the listener’s intended output are correctly matched.
An illustrative example
A player sends E-AC-3 through a television that cannot forward that format on the selected return-audio route. The soundbar remains silent despite supporting E-AC-3 on another input. Local decoding to an accepted PCM layout restores sound, showing that the complete route mattered more than the final decoder alone.
Practical actions
- Identify the incoming codec on the receiver during playback.
- Check every forwarding device and connection.
- Compare supported PCM output with one passthrough codec at a time.