What is the difference between 2.1, 5.1 and 7.1?

The designations 2.1, 5.1 and 7.1 describe how many audio channels a sound system has.

The first number indicates the number of regular audio channels, while the number after the decimal point indicates the number of separate low-frequency effects channels (LFE).

In practice, these designations are also used to describe the number of speakers and subwoofers in a system.

What is a 2.1 system?

A 2.1 system usually consists of:

• Two stereo speakers, left and right.

• One subwoofer.

It is a common option for music listening and simpler TV systems.

What is a 5.1 system?

A 5.1 system usually consists of:

• Two front speakers.

• One centre speaker.

• Two surround speakers.

• One subwoofer.

The centre speaker often reproduces much of the dialogue, while the surround speakers contribute to the sound experience around the listening position.

What is a 7.1 system?

A 7.1 system builds on 5.1 by adding two rear surround speakers.

This can provide a more detailed sound experience behind the listening position, particularly in larger rooms.

What do 5.1.2 and 7.1.4 mean?

When a home cinema system has three numbers, the third number describes the number of height channels.

For example, 5.1.2 means:

• Five regular audio channels.

• One low-frequency channel.

• Two height channels.

Height channels are used for formats such as Dolby Atmos and can be reproduced by in-ceiling speakers or dedicated Atmos speakers.

Which system should I choose?

For music listening, a 2.1 system can be quite sufficient.

If you want surround sound for films and TV, 5.1 is a common starting point.

A 7.1 system may be worth considering if you have a larger room and can position more speakers correctly.

Tip: A well-positioned 5.1 system can provide a better experience than a 7.1 system with incorrectly positioned speakers.