Comparison of Game Consoles by Sound Capabilities

The purpose of this article is to categorize video game consoles according to their supported audio formats, and to consolidate advice on optimizing sound reproduction for each of those consoles.

Explanation of Terms
If you’re getting started with optimizing a console setup for audio, there are some numbers that you’ll notice like 2.1, 5.1, 7.2.2 and so on. These numbers represent speaker channels, and they follow a specific format.
 * The first number defines how many main channels there are in the setup, at ear level. Each is typically implemented with a single speaker (box), containing one or more drivers (the actual electromagnetic transducers), in which case each tends to specialize in a certain frequency range.
 * The second number stands for the number of subwoofer speakers in the setup, which are dedicated to low-frequency bass sounds. The subwoofers are commonly placed at floor level. Having a single speaker for extreme bass is cost-efficient because effective reproduction of these sounds (and felt vibrations) benefits from a physically large speaker that would not be practical to duplicate for each channel; this does not significantly compromise audible fidelity because human hearing lacks directionality at low frequencies.
 * In more modern home theatre setups (e.g., 7.2.2) there is a third number, which defines how many “Dolby Atmos” in-ceiling speakers there are to provide overhead sound.

Analog multichannel sound (which, contrary to literal meaning, usually refers to systems with 3 or more channels) can be implemented as:
 * a discrete system, where each channel is delivered independently; (for example, a 5.1 system with 5 or 6 RCA connectors is, at least at that point in the chain, a discrete system)
 * a matrixed system, where various algorithms are used to put multiple channels worth of sound into a lesser amount of physical channels (as would be required on a record, where stereo sound already uses both dimensions available for stylus movement, and desirable elsewhere for backwards compatibility and/or cost saving).

In digital audio, these terms are less commonly used, but comparable approaches are used depending on circumstances (for instance, the S/PDIF interface was designed for the bandwidth of 2-channel PCM and multichannel use requires classic matrixing, the switch to a lossy codec such as AC3 or DTS which may not be compatible with the output device, or the switch to a completely different interface).