Stereo is sound recorded and played back on two separate channels, left and right, through two speakers. Because each speaker plays a slightly different signal, your brain hears the music spread out between and around them, with a singer in the middle and instruments placed left and right, much as you would hear them live. "A stereo" also means the system that plays it: a pair of speakers, an amplifier and a music source. This guide explains how stereo works, how it differs from mono and surround, what you need, and how to set up two speakers so they sound their best.
How stereo works
When music is recorded and mixed, each instrument and voice is placed somewhere between the left and right channels. A sound that is equally loud in both channels appears to come from the exact middle, even though there is no speaker there. This is called the phantom centre, and it is where the lead vocal usually sits. A guitar mixed more into the left channel appears to the left, and so on.
Two terms describe how well a pair of speakers does this:
- Imaging: how precisely you can point to where each instrument is.
- Soundstage: how wide and deep the whole performance sounds, often stretching beyond the speakers themselves.
Good imaging depends on the speakers, but just as much on where you put them, which is why setup matters (see below).
Stereo vs mono vs surround
| Channels | Speakers | Best for | |
|---|---|---|---|
| Mono | 1 | 1 (or the same signal from 2) | Early recordings, speech, a single smart speaker |
| Stereo | 2 (left, right) | 2 | Music: almost every album since the late 1960s is mixed in stereo |
| Surround (5.1, 7.1) | 5 or 7, plus a subwoofer channel | 6 or 8 | Films and TV, where sound moves around and behind you |
For music, a good stereo pair is usually the better investment than a surround system at the same budget, because the music was mixed for two speakers. If you also watch films, a stereo system can grow into surround later by adding a centre, surrounds and a subwoofer. Our guide to the types of loudspeaker explains each one.
A short history
Stereo was invented in Britain. In 1931 Alan Blumlein, an engineer at EMI, patented a way of recording and reproducing sound on two channels so that it kept its sense of direction. It took until 1958 for stereo records to go on general sale, and within about a decade stereo had become the standard for music. Wharfedale, founded in Yorkshire in 1932, has been making loudspeakers through the whole of that story.
What you need for a stereo system
- A pair of speakers. Bookshelf speakers suit small to medium rooms; floorstanding speakers suit larger ones. Not sure which? Read bookshelf vs floorstanding speakers.
- A stereo amplifier. Most Wharfedale speakers are passive, so they need an amplifier (or a stereo receiver) to power them. Match the amplifier to the speaker's impedance and recommended power, listed on every product page.
- A source. A turntable, CD player or streamer. Many modern amplifiers have streaming, Bluetooth or a phono stage built in, which keeps the system to just two boxes and a pair of speakers.
Good starting points are the Diamond 12.1i and EVO 5.2 bookshelf speakers, or the Linton for a classic look. Our bookshelf speaker guide compares them model by model.
How to set up stereo speakers
- Make a triangle. Put the two speakers and your listening seat at the corners of an equal-sided triangle. In most rooms that means the speakers are 2 to 3 metres apart, and you sit about the same distance from each.
- Angle them in slightly. Turning the speakers a little towards your seat (called toe-in) usually sharpens the centre image. Try small changes and listen to a vocal track.
- Tweeters at ear height. Put bookshelf speakers on stands rather than low furniture, so the tweeters are level with your ears when you are seated.
- Give them space. Keep speakers some distance from the wall behind them (more for rear-ported designs) and the same distance from each side wall, so the room affects both equally.
- Check the wiring. Connect red to red and black to black on both speakers. If one is reversed, the bass thins out and the centre image goes vague.
Frequently asked questions
What does stereo mean?
Stereo means sound reproduced on two channels, left and right, through two speakers, so that it has a sense of width and direction. The word comes from the Greek for "solid", as in sound with shape. "A stereo" is also everyday shorthand for a home music system.
What is the difference between stereo and mono?
Mono uses a single channel, so everything comes from one point. Stereo uses two, so instruments and voices are spread out between the speakers.
Is stereo better than surround sound?
For music, usually yes, because almost all music is mixed in stereo. Surround is better for films and TV, where sound effects move around the room.
Do I need two speakers for stereo?
Yes. Stereo needs a left and a right speaker. A single speaker, even one with two drivers inside, cannot place sounds between two points the way a separated pair can.
How far apart should stereo speakers be?
About as far apart as you sit from them, typically 2 to 3 metres, so the speakers and your seat form an equal-sided triangle.
Can I add a subwoofer to a stereo system?
Yes. A subwoofer adds the deepest bass, which helps with smaller speakers or a larger room. See what size subwoofer do I need?
Want to hear the difference good stereo makes? Book a demonstration at a Wharfedale dealer near you, or contact us for advice.
