All these systems use what is called multichannel audio, designed to enrich the listening experience by reproducing different parts of the overall sound on different speakers. This is how they work:
- 2.0 — Stereo, the most basic multichannel system, has separate speaker cabinets for left and right audio channels. Each speaker cabinet will have a minimum of one full-range speaker (also known as a driver), but often a speaker cabinet will include a combination of two or three different kinds of drivers, such as: a woofer for low (bass) frequencies; a tweeter for high (treble) frequencies; and/or a mid-range speaker, also sometimes known as a squawker.
- 2.1 — Stereo plus a subwoofer (a separate speaker unit for reproducing only the lowest bass frequencies). The deep rumble of the subwoofer adds depth to the overall sound.
- 5.1 — Surround sound. Five speakers plus a subwoofer. The speakers are left, right and middle channel in front, plus left and right-rear and a subwoofer.
In all cases, the speakers were set up according to the nature of their channel configuration, but taking into account that they are PC speakers and designed to be used in conjunction with a computer system, typically a user sitting at a desk.
Note that the constraints of desktop size means that these kinds of speakers will generally be closer to the user than is the case with lounge room speaker systems.
At this relatively close proximity, even small speakers can deliver good sound if they are high quality units.
Ambience: The acoustic characteristics of a space with regard to reverberation. A room with a lot of reverb is said to be 'live'. One without much reverb is 'dead'.
Bass: The lowest part of the audio range (20-140 Hz.)
Body: Sound consistency or density, richness, substance.
Definition: The quality of a sound that allows it to be distinguished from other sounds.
Image: The localisation of individual sound sources in threedimensional space.
Responsiveness: The quality or state of being responsive, the ability of a speaker system to adjust quickly to suddenly altered external conditions.
Treble: The highest part, voice, instrument, or range (5000-20,000 Hz).
Warmth: A listening term. The opposite of cool or cold. Generally considered the frequency range from approximately 150Hz-400Hz. A system with the 'proper' warmth will sound natural within this range.