Mono vs. Stereo – What’s The Difference?

Martin Kristiansen

My name is Martin Kristiansen and I’m the founder and chief editor of HomeStudioIdeas.com. I’ve been playing, recording and producing music for the last 10 years.

No matter what you’re listening to, the sound is an important part of the experience. While we usually don’t think too much about how that sound is delivered to us, there are two different ways it can be done: mono and stereo.

But what exactly is the difference between the two? Read on to learn more about Mono vs. Stereo!

If you’re in a hurry, here’s a quick rundown: 

The difference between mono and stereo is the number of channels that they send to the speakers.

Mono audio uses a single audio channel, meaning that all sounds come from one speaker. Sure, the same waveform can be sent to two speakers, but it’s still not stereo.

This is the simplest form of audio playback. 

In opposition, stereo audio uses two audio channels (left and right) to create a more immersive soundscape, similar to how we actually hear stuff. Each audio channel is then sent to the left and right speakers.

But there is more to it. Let’s take a look!

How Our Brain Determines The Source Of A Sound

Before we start digging into mono vs. stereo, we should take a step back and learn how our brain manages to localize sound.

For what reason?

You see, this is how stereo systems tricks our mind!

Sound localization is an important part of our survival instinct. When we hear a noise, we need to be able to determine where it is coming from so that we can take appropriate action.

Our brain uses several cues to help us determine the direction of a sound.

One cue is the difference in time that it takes for sound waves to reach each ear. This is called the interaural time difference, or ITD. Our brain uses the ITD to help us localize sounds that are far away.

Another cue is the interaural level difference, referred to as ILD. This occurs when sound waves reach our ears at different intensities, and the ILD helps us locate sounds that are closer to us.

Luckily, your brain is easy to trick. Otherwise, we would only perceive sounds from the hard left and hard right, leaving a hole in the center of the stereo speaker system.

What Is Mono?

Let’s start by defining the term “mono”.

Mono, short for monaural or monophonic, is an audio signal that is single-channeled and has one audio track. This contrasts with stereo sound, which uses two channels and two audio tracks.

Mono audio can be played on both mono and stereo systems, but there is only one unique waveform.

The word mono comes from the Greek word monos, meaning “one”, “single”, or “alone”.

The term monaural refers to recordings made using only one microphone, while the term stereophonic refers to recordings made using two or more microphones. 

Mono recordings are made by combining sounds of different instruments into one waveform. This results in a recording that is less spacious, but more distinct from each other.

What Is Stereo?

Stereo is a technique for reproducing sound using two or more independent audio channels in a way that creates the impression of directional hearing.

Furthermore, the word “stereo” comes from the Greek root meaning “solid” or “three-dimensional.”

When you listen to music on a stereo system, you are hearing sounds that have been recorded using two or more separate microphones.

These sounds are then mixed and reproduced through the left and right speakers. The result is a three-dimensional sound that gives you the illusion of being surrounded by music.

Fake Stereo

When you’re working with mono files in your mixing workflow, it’s sometimes necessary to fake stereo to be able to add width to your tracks.

How does it work?

Faking stereo is done by manipulating the time difference between two mono files. 

First, duplicate the mono file and add the duplication to a new track.

Then, delay the duplicate by a few milliseconds.

Last but not least, pan the two tracks in different directions. This creates a sense of space and width in your mix.

Remember ITD and the time differences? When offsetting one of the mono files, we’re creating an illusion and taking advantage of our brain’s natural ability to localize sound.

You see, waveforms from two different sound sources will never reach our eardrums at the exact same time.

Our brains are very good at detecting small differences in timing, which will trick us into thinking there are two separate sources of sound.

Mono vs. Stereo Audio Files

When it comes to audio files, mono and stereo are also distinguishable. 

As you might have guessed, mono files have one channel, while stereo files have two channels. The left channel is the main channel, and the right channel is the secondary channel.

When you open a mono audio file in your DAW, you will see one waveform. This waveform represents the sound of the entire file.

On the contrary, you will see two waveforms when you open a stereo audio file. The left waveform represents the sound of the left channel, and the right waveform represents the sound of the right channel.

Easy right?

You see, mono files are limited to playing back one sound at a time, while stereo files can play back two sounds simultaneously.

Mono vs. Stereo Recording

In general, all songs that you listen to include a mix of mono and stereo tracks.

Still, mono recording is when a single microphone is used to record sound. This is the most basic type of recording.

The main advantage of mono recording is that it’s very focused and simple to set up. Mono recordings can be made with just a few pieces of equipment, making them ideal for bedroom producers.

Nevertheless, the biggest disadvantage is that they can sound flat and one-dimensional.

Why?

Because all the sounds are combined into a single track, which doesn’t allow for much separation between different instruments or sounds.

In addition, stereo recordings are when multiple microphones are used to capture the sound source.

Stereo Mic Techniques

So how do you record with multiple microphones? Stereo recording techniques are a chapter on their own, and I won’t go into heavy detail here. For now, the three most common techniques are:

Spaced Pairs (A/B)

In stereo recording techniques, spaced pairs are the most basic technique. It involves two identical microphones placed 3 to 10 feet apart. This creates a sense of spaciousness and width in the recording.

Moreover, the microphones capture the timing and level of sounds differently from their respective positions.

These sounds are then combined to create a more three-dimensional image. This image is more realistic and provides a better immersive experience for the listener.

Spaced pairs are an effective way to create a wide soundstage. It can be used in both live and studio recordings. Additionally, this technique is especially useful for capturing the ambiance of a room or outdoor space.

X-Y Pair

The X-Y Pair is a coincident pair of two microphones placed at one location above each other. This technique is used to obtain positional accuracy by using the time delay between the signals from each microphone.

Furthermore, the X-Y pair is usually placed in a V-shaped formation, 90 degrees from each other.

Mid/Side (MS)

The Mid Side (MS) recording technique is a great way to capture the ambiance of a room while still maintaining a strong center channel.

As you would’ve guessed – Mid/Side involves using two microphones, a mid mic, and a side mic.

The mid mic is placed in the middle of the room, pointing straight ahead. The side mic is placed directly to the side of the room, pointing at an angle of 90 degrees.

The figure-8 pattern of the side mic picks up sound from both sides of the room, while the mid mic captures sound directly in front of it.

This combination creates a strong center channel with plenty of ambiance.

Stereo Microphones

Your typical microphone record in mono. That’s why you would need at least two microphones to record in stereo.

However, a stereo microphone is a single unit with two built-in microphones.

The two built-in microphones are positioned so that they mimic the way our ears hear a sound, providing depth and directionality to the recording.

How?

Time differences! Remember the interaural time difference (ITD)?

Furthermore, stereo microphones are used in a variety of applications, from live music concerts to field recording and video production. They offer a convenient way to capture high-quality stereo audio in one device.

When Should I Record In Mono?

Truth be told, your project in your DAW should mostly contain mono tracks. Recording in mono is your best bet.

Why?

There aren’t that many sound sources that have a natural spread that needs to be captured with two or more microphones.

Remember, mono tracks can still be panned to any location, and the easiest way to achieve a wide-sounding mix is to spread your mono tracks out in the stereo image.

As a rule of thumb, these instruments should always be in mono:

When Should I Record In Stereo?

In addition, record in stereo when you want to capture instruments with natural spatial qualities. Also, it’s better to record in stereo if you’re recording an ensemble.

How come? The placement of instruments in a room is relative to each other, and you would want to capture that.

I usually record these instruments with two or more microphones:

In my experience, recording these instruments in mono can sometimes make them sound flat and two-dimensional.

Mono vs. Stereo Playback

Stereo Speakers

As you would’ve guessed, a stereo speaker system is a pair of speakers that output two channels, typically left and right.

The stereo effect is created by having separate non-unique audio signals for each speaker. This creates a more realistic and spatial sound, similar to how our brain interprets sound waves picked up by our ears.

Stereo speaker systems utilize three dimensions (stereo image) for sound source localization:

When you listen to music on a stereo system, the speakers are positioned so that the left and right speakers are directly in front of you.

Then, the same signal is sent to both speakers, but with timing differences created by the two microphones. This creates the illusion that the sound is coming from different directions.

The left and right positioning of the speakers allows for sound localization. Your brain uses these timing differences to determine where the sound is coming from. This allows you to hear music in stereo and enjoy a fuller, richer sound.

In contrast, you’ll perceive the sound to be in the center of both speakers if they’re feeding you the exact same signal at the same loudness levels.

Mono Speakers

For starters, a mono-speaker system is a sound system that emits sound waves in one direction and is commonly found in laptops, computers, and iPhones.

Besides, the sound waves emitted are usually directed toward the listener, making it easier for them to hear the audio.

While stereo speaker systems form a 3-D space, mono speaker systems can only create two dimensions.

Those includes:

Obviously, Width-dimension (timing differences) between two speakers are non-existent on mono systems.

Stereo Field

The stereo field refers to the placement of audio signals within a stereo mix. Think of it as a 180-degree virtual space where you can place sound sources either left, right, front, or back (or anywhere in between).

Why am I telling you this? You see, the stereo field is an important aspect of mixing and mastering.

What Is Stereo Imaging?

Stereo imaging is the process of manipulating the 180-degree stereo field so that various signals can be placed anywhere within, from dead center to hard left or right.

It’s commonly used in recording and mixing to create a sense of space and depth.

With proper stereo imaging, you can make a recording sound wide and open, or tight and focused. You can also use it to bring out certain elements in a mix, push them back, or place them in specific locations within the stereo field.

Stereo imaging is an important tool for any recording engineer or music producer. With it, you can create a sonic landscape that enhances the listening experience and brings your music to life.

Stereo Imaging Plugins

Stereo imaging plugins are software that can be used to enhance the stereo image of a track. By using a stereo imaging plugin, you can add width and depth to your track, making it sound fuller and more polished.

There are tons of stereo imaging plugins available to download, both free and paid.

Free Options

Paid Options

Conclusion

Both stereo and mono are two separate ways that sound is delivered to us through speakers. 

Stereo audio is created using two channels, while mono audio only uses one. Consequently, stereo audio will have a wider soundscape, offering listeners a more immersive experience.

On the other hand, mono recordings can sound more focused and intimate. They’re still the most common type of audio when recording and producing music, and they can be panned to any location within the stereo field.

And there you have it – The differences between mono and stereo audio. If you have any questions, please let me know in the comment section below!

Till next time!