In digital devices, audio can be processed using software decoding methods. For example, in laptops, the central processor plays a key role in decoding the audio stream. To ensure proper playback, special programs called codecs are required. However, this approach puts a load on the processor and consumes its resources.
To reduce the load on the main processor, manufacturers use hardware audio decoders. These can be specialized chips embedded in the main board or separate devices with built-in audio processors. In this case, audio processing is handled not by the central processor but by a dedicated decoder that already contains the necessary codecs.
In the past, standalone audio decoders were commonly used in desktop computers. In televisions, however, audio decoders are usually built into the main board. They can be developed by different manufacturers, such as Dolby MS12, a built-in audio decoder that supports basic codecs as well as Dolby formats.
These devices can be integrated as separate chips on the board or exist as external modules. In the latter case, they are primarily used for outputting sound to speaker systems and are designed to process digital audio signals (optical or HDMI), converting them into an analog format that can be played by speakers.
Separate Audio Decoder Boards for PCs
Previously, this configuration was widely used, but today it is much less common. The main reasons are its more complex design and the need for additional audio amplifiers to output sound to speakers. It is much easier to integrate the decoder directly into the sound system.
Below is an example of an audio decoder board for a PC.
External Audio Decoders
There are also standalone audio decoders that serve various purposes. For instance, if you have an outdated speaker system or receiver, it may not support modern audio formats or lack optical or HDMI inputs while still functioning well as an amplifier. Purchasing a separate decoder allows you to upgrade your system to meet modern standards.
What Is an Audio Decoder?
Some basic audio decoders can only process stereo sound, decoding just two channels—left and right (2.0). A 2.1 decoder not only decodes stereo channels but also extracts low-frequency signals for a subwoofer.
A 5.1 decoder can process sound on six channels:
- Left (Front Left)
- Right (Front Right)
- Center
- Two rear channels (Rear Left and Rear Right)
- Subwoofer
A 7.1 decoder adds two additional side channels, further enhancing surround sound.
Dolby Atmos decoders take this a step further, creating immersive 3D audio for a more realistic and spatial listening experience.
