2.0 vs 2.1? 5.1 vs 7.1? And, what is Dolby Atmos 5.2.2? Learn all about audio channels in this guide to stereo, surround sound & Dolby Atmos speaker layouts.
Table of Contents
- What are Audio Channels?
- 2.0 Stereo Sound
- 2.1 Stereo Sound
- 3.0 Speaker System
- 3.1 Speaker System
- 5.1 Surround Sound
- 6.1 Surround Sound
- 7.1 Surround Sound
- 7.2 Surround Sound
- Dolby Atmos Speaker Layouts – 5.1.2 and 7.2.4
- Frequently Asked Questions
Choosing the best speaker layout for your room can be one of the hardest things to decide. The problem is, there are so many ways you can go.
For stereo setups, there are two main options: 2.0 and 2.1.
A 2-channel stereo system plays the audio from both channels – left and right. In contrast, a 2.1-channel system adds a subwoofer to the left and right channels.
For a surround sound system, there are more options.
A 5.1 channel system separates the audio through multiple speakers – left, center, right, surround left, surround right and subwoofer. And a 7.2 surround system adds two more rear speakers and an extra subwoofer.
Finally, what about a 5.1.2 Dolby Atmos layout with two more speakers for a 3D effect?
Let’s take a look in more detail at each of these options – and, while I’m at it, I’ll suggest a few more on the way.
What are Audio Channels?
For live or recorded audio, an audio channel is the position of an audio source in an audio signal.
For amplifiers and speakers, an audio channel is a way of transporting that audio signal.
For example, in the early days of sound recording, engineers recorded the sound in mono – a single-channel audio source. Devices that played this sound had one speaker – like early gramophones, radios and TVs.
Later, sound recording evolved to use stereo audio which used two audio channels – left and right. This meant that engineers could mix musical instruments in a stereo field.
However, it also required amplifiers to have two speaker channels connected to the left and right speakers – one channel for each speaker.
In modern movie soundtracks, we now use audio that has several audio channels for surround sound.
A surround sound amplifier must have multiple channels to send the audio to all the surround speakers around the room. The one pictured above has 7-channels.
Now that you understand what an audio channel is, let’s look at the different speaker layouts commonly used in music and movie audio reproduction today.
2.0 Stereo Sound
Do you have a sound system to play music? If so, it is probably a stereo system.
We all know what stereo is, right?
Stereo systems have two speakers – one for the left audio channel and one for the right. A system like this can also be called a 2-channel or 2.0 system.
The ‘2’ means it has left and right speakers for playing two-channel sound. Most music and TV shows come with stereo sound.
The ‘.0’ implies this type of system doesn’t use a subwoofer. We’ll talk more about subwoofers in a minute.
If you do have a good stereo speaker system at home, you might be able to use this for your home theater sound.
For this, you will need an amplifier that has a spare stereo audio input. If so, connect the audio output from your video source – like your DVD or Blu-ray player – into the amplifier’s input.
Bingo! That’s improved the sound already.
Although most people assume that you should hear home theater audio in surround sound – don’t forget that most TV audio is still broadcast in stereo. And, every movie disc will have a stereo mix of the soundtrack.
While it’s great to have a surround sound system – you can get an excellent quality stereo amplifier and speakers for the price of a mid-range surround sound system.
Your stereo TV and DVD audio will sound fantastic – plus you’ll have a system which will sound great for listening to music too!
Find out more in my guide to using stereo receivers for home theater.
2.1 Stereo Sound
2.1 stereo sound is similar to a 2.0 stereo setup – with two speakers for the stereo left and right audio channels.
The difference is that we also have a subwoofer speaker connected to the system. If you see any speaker configuration with a ‘.1’, it indicates it has a subwoofer.
The subwoofer isn’t technically a channel because it takes low-level audio from both the actual audio channels. So, a 2.1 amp is a two-channel amplifier with a subwoofer output.
A subwoofer is a speaker dedicated to bass frequencies. Most hi-fi speakers sound OK for mid-range and high frequencies – but many can’t reproduce the low frequencies that well.
Although, large floor-standing speakers can give a great bass sound.
A subwoofer fills out the low end really well and creates a better-balanced sound.
It makes a massive difference to the sound if you get good bass along with the mid and high frequencies. It will also really improve your movie experience with some of the special effects.
The easiest way to get a 2.1 setup is to buy an amplifier with a dedicated subwoofer output channel.
However, there is a potential problem with this – there aren’t that many stereo amplifiers with a subwoofer output.
There is another way. Some subwoofers have two different types of connections:
- Low-level input: the ‘standard’ input that you connect to the dedicated sub pre-out on a receiver. This will be a single phono connection.
- High-level input: often a Neutrik Speakon connection for taking the full audio signal from the front left and right speakers.
So, if you purchase a subwoofer with a high-level input, you can connect your stereo amplifier in this way.
You will then use the volume and filter controls on the subwoofer to balance the low bass audio with that of your stereo speakers.
Learn more about how to wire a subwoofer.
If those options aren’t right for you, then other options are to:
- buy a 5.1 AV receiver and just connect it to a front left/right pair and subwoofer.
- buy a home-theater-in-a-box-system or soundbar system
So, which of these two stereo speaker layouts should you use?
2.0 vs 2.1 Speaker Layouts
Now that you understand the difference between 2.0 and 2.1-channel systems, which is best for you? Here are some thoughts.
Reasons to use a 2.0 system:
- You like the sound of your stereo speaker system as it is
- You don’t have space for a subwoofer
- A 2-channel amp with no subwoofer is cheaper
- You don’t need to spend more money on a subwoofer
- You are likely to get more bang for your buck with a simple stereo amp and speaker system
- You don’t have to worry about getting the right tonal balance between stereo speakers and subwoofer
Reasons to use a 2.1 system:
- You are happy with a stereo system, but you feel your current 2.0 hi-fi system doesn’t give you enough bass for music.
- You want more bottom end for movie effects.
- You can get a really low-end sound that is hard to get from stereo speakers.
- You enjoy the flexibility of setting up a subwoofer in your room.
- You can use the stereo speakers for music – and only enable the subwoofer for movies.
There isn’t a correct answer to this. It depends on your budget, what material you will play and what sounds best to your ears.
I prefer a system that has a subwoofer for both music and movies. I guess because I used to play bass guitar in bands, I got used to that feel of bass from a larger speaker. You feel it more than you hear it.
However, many audiophiles prefer a more straightforward setup and the clean sound they get from their standalone stereo pair. If they want more bass, they will buy floor-standing speakers.
There isn’t a right or wrong answer – just a matter of taste.
3.0 Speaker System
If you don’t want to install a complete surround sound system but want to improve the sound for TV and movies, then a 3.0 speaker system might be perfect.
A 3.0 speaker system has a center speaker in addition to the left and right stereo speakers.
Why is this an improvement over 2.0?
Well, because surround sound movies are mixed with the center channel taking most of the dialogue.
So, the advantage over a 2.0 setup is the extra center speaker will allow greater separation of voices and music.
This will improve the clarity in a busy soundtrack.
You can either buy a dedicated 3.0 system or get a 5.1/7.1 AV receiver and just connect the front three speakers.
When you set up your AV receiver, you can tell it that you don’t have surround speakers at the rear, and it will play a 5.1 soundtrack minus the rear effects.
Advantages of a 3.0 speaker layout:
- Better performance with TV and movies
- A center speaker will improve the clarity of dialogue
- You can alter the volume of the center speaker to your taste
Of course, if you play stereo music or TV shows, you will only use the stereo speakers, and the center speaker will be redundant.
Although, if you have an AV receiver, you could enable Dolby Surround or DTS Neural:X, which will use the center with stereo sound.
If you prefer a system based around a soundbar, you can buy soundbars with dedicated center speakers. It can sometimes be difficult to tell if a soundbar has a center speaker or not.
My guide to buying the best soundbars has some options for you to consider.
3.1 Speaker System
If you’ve been paying attention – and I don’t doubt it for a minute – then you will know what a 3.1 speaker system is.
It will have a front left, center, and front right speaker like the 3.0 layout, but it will also have a separate subwoofer.
Why would you prefer a 3.1 system over 3.0? The reasons are the same as I discussed earlier with 2.0 vs. 2.1.
The subwoofer will give you a much better bottom-end. This can work well for music – but will really come into its own for movie soundtracks.
So, which is better, a 3.1 or 2.1 speaker system? As always, it depends!
Advantages of a 2.1 system:
- Cheaper to buy
- You can buy a 2-channel hi-fi amplifier which may well provide better sound quality for the money
- Works great for music – OK for movies
Advantages of a 3.1 system:
- Separate center speaker for movie and TV dialogue
- Adjustable volume for the dialogue
- Works better movies – OK for music, but you will need to spend more money on a multi-channel amplifier to get similar sound quality to a dedicated stereo amplifier.
The bottom line is that a 3.0 or 3.1 speaker setup will work better for TV and movies because of the center speaker.
5.1 Surround Sound
Surround sound! You’ve just gotta love surround sound. This is where it gets enjoyable with home theater speaker systems.
If you haven’t heard it in action, then you must. You must!
A 5.1 speaker system is the standard home theater speaker layout.
Pretty much all DVDs and Blu-rays will have a 5.1 surround sound soundtrack these days – as well as a stereo mix too.
A movie will sound fantastic if you’ve got a good 5.1 speaker system in the room.
A 5.1 surround sound installation has six speakers in total:
- Front left and right (which is the equivalent of your stereo speakers)
- Front center (mainly used for dialogue)
- Surround left and right (it’s behind you!)
- A subwoofer (for low bass)
You’ll need an AV receiver that has five channels to connect the center, front left, front right, surround left and surround right speakers.
It will also have a subwoofer output (sometimes called an LFE) to connect to your sub.
The AV receiver is sent the digital audio signal from the DVD/Blu-ray player – and the receiver then decodes it and sends the audio to the correct speakers.
When you connect this speaker setup to a good AV amplifier, then the results can be superb. If your system is well balanced, a good 5.1 mix will definitely make you feel part of the action.
The sound should completely immerse you in the movie – with a mixture of music and sound effects that completely surround you.
Did I tell you I think surround sound is excellent?
If you’re not sure what speakers to buy, take a look at my guide to the best speakers for surround sound systems.
6.1 Surround Sound
6.1 is a less common speaker layout, but some soundtracks are encoded for 6.1 surround. You may see some discs with DTS-ES Matrix6.1 or Discrete6.1.
A 6.1 speaker layout is the same as 5.1 but with a single extra speaker behind your main listening position.
Your AV receiver will need to support this audio format – plus have an extra channel to power the additional speaker.
In practice, you will need to buy a 7.1 AV receiver for this.
7.1 Surround Sound
7.1 speaker systems are very similar to their 5.1 counterparts – but there are two extra speakers at the rear.
The purpose of the extra rear speakers is to get even more control over the sense of space in the room.
Many new AV receivers come with enough output channels to connect a 7.1 system (or more).
However, you don’t need to connect all seven outputs if you don’t have space – or enough speakers.
So you can use these in a 5.1 configuration too. You can always add more speakers later.
The biggest issue with 7.1 surround sound is that not many movies are mixed with a 7.1 soundtrack – although there are a few. So, you may wonder what the point is.
Well, a 7.1 AV receiver will have some digital audio processing modes where it will fill the extra speakers with sound from the 5.1 soundtrack – giving the illusion of more space.
Therefore you will still get the benefit of having two extra speakers in the room.
See my guide to AV receiver listening modes for more on this.
You will generally need a bit more space in your room to connect a 7.1 sound system. The extra rear speakers really need to be behind the seating in your home theater – so that’s going to be tricky if the seat is pushed back against the wall.
However, given enough space in your room to position your speakers correctly – a 7.1 system can provide you an even better surround sound experience than 5.1.
Here are some tips if you are trying to choose between a 7.1 and 5.1 system.
5.1 vs 7.1 Surround Sound
Advantages of a 5.1 speaker setup:
- A 5.1 receiver will be cheaper
- You can buy a more affordable speaker package
- Most soundtracks are 5.1, not 7.1
- Fewer speakers in your room
- Easier installation
- Requires less space in your room
Advantages of a 7.1 speaker system:
- Most AV receivers have a minimum of 7-channels anyway.
- Better surround sound effect.
- Most receivers will have a digital processing mode, which will create a 7.1 mix from a standard 5.1 soundtrack.
- You can use the extra two channels to power Dolby Atmos speakers instead.
Don’t forget, if you buy an AV receiver that supports 7.1, you can use it for 5.1 surround sound to begin with. Then add more speakers later if you want to switch up to 7.1.
7.2 Surround Sound
More and more AV receivers now support this type of surround sound speaker layout.
A 7.2 speaker system is the same as a 7.1 setup – except it has two subwoofers – hence the ‘.1’ is increased to ‘.2’.
Therefore, a 7.2 surround sound receiver would have two subwoofer outputs rather than the usual one.
The main reason to have a second subwoofer is to even out the bass sound throughout your room. The long wavelengths of bass sound waves can create standing waves in your room, which can lead to areas of quiet or loud bass.
Now, this isn’t a situation we want in our home theater, as it is obviously better to have a consistent bass level regardless of where you are sitting in the room.
Therefore, if we place a second subwoofer somewhere else, we will fill in the gaps and create a more even spread of the bass.
You can use this second subwoofer in a 5.1 surround sound setup, too – and you will create your very own 5.2 surround sound system!
Another advantage of a ‘.2’ system is you shouldn’t need to drive two subwoofers as hard as you would with just one to get a good bass level, which may result in a better, less overdriven sound.
Whatever the reason for using two subwoofers, the speaker positioning would vary from room to room depending on the acoustics – and so it is impossible to say exactly where you should position your second subwoofer.
However, it may just be a simple case of having one near the front and one near the back or side of the room.
As the bass sound from a sub is not directional, it shouldn’t matter where you place the speakers; it is just the overall bass cover you are concerned with.
Go to this article for more on subwoofer speaker placement.
Dolby Atmos Speaker Layouts – 5.1.2 and 7.2.4
Just when you thought you had the hang of this, I spring another speaker layout on you.
If you see a third number after the usual 5.1 or 7.1 layouts, this refers to speaker layouts for object-orientated 3D audio – such as Dolby Atmos and DTS:X.
These are newer audio formats that have moved away from the traditional reliance on fixed audio channels.
With object-oriented audio, soundtracks are mixed using audio objects that can be placed anywhere in the sound field. They are not tied to the traditional 5 or 7-channel configurations.
Although these soundtracks will support traditional 5.1 and 7.1-channel systems, they can be played on a wide range of speaker configurations. The AV receiver will alter the output depending on how many speakers are connected.
A Dolby Atmos system requires a least two more speakers in addition to the usual ones. This is the extra ‘.2’ at the end of 5.1.
The extra two speakers can either be:
- Upfiring Atmos speakers: usually placed on top of your front left and right stereo pair and pointing towards the ceiling.
- Down firing speakers: placed somewhere on the ceiling and pointing down into the room. These can be in several different positions – the front, middle or rear of the room being the most common. When you set up your AV receiver, you just need to tell it where they are located.
For a DTS:X soundtrack, you don’t need to have the extra speakers. The audio objects will simply appear around the traditional 5.1 or 7.1 speaker system. You may also see other speaker layouts using this format.
- 5.1.4: a 5.1 system with four Atmos speakers
- 7.2.6: a 7.2 system with six Atmos speakers
Dolby Atmos can support speaker layouts up to 24.1.10. Although, you won’t find any consumer AV receivers with that many channels.
Frequently Asked Questions
Is 5.1 or 7.1 Better?
The difference between 5.1 and 7.1 surround sound isn’t huge. If you have space and can install the extra speakers in the correct positions, you will get an extra immersive feel. However, a correctly set up 5.1 system will be better than a poorly configured 7.1 surround sound system.
Is 5.1 Good Enough?
Yes, 5.1 is ideal for most people to get a great surround sound experience. You don’t have to spend more on 7.1 or Dolby Atmos to really enjoy a movie. However, if you have the money and the room, you can take things further with more speakers.
5.1 vs 7.1 vs Atmos?
A properly configured 5.1 system will be enough for most people. 5.1 surround sound will give you a fantastic movie experience. If you are an enthusiast and have some cash to spare, installing two extra speakers for a 7.1 system can create an even better surround sound effect. If you need to choose between 7.1 or Dolby Atmos, I would install two Atmos speakers to create a 3D sound. Atmos will bring more excitement to the room than 7.1. But, if money is no object – get both. 7.1 with Dolby Atmos is as good as it gets.
2.1 vs 5.1 For Music?
If music is your primary focus, a 2.1 speaker system will be best. You will be able to buy a better stereo amplifier that has excellent sound quality. If it doesn’t have a subwoofer output, you can always connect the sub using a high-level connection. If you buy a 5.1 amplifier, you will need to spend much more to get a similar sound quality to the 2-channel amp.
About Home Cinema Guide
Paul started the Home Cinema Guide to help less-experienced users get the most out of today's audio-visual technology. He has worked as a sound, lighting and audio-visual engineer for around 20 years. At home, he has spent more time than is probably healthy installing, configuring, testing, de-rigging, fixing, tweaking, re-installing again (and sometimes using) various pieces of hi-fi and home cinema equipment.