If you are a music producer, then most likely you’ve heard of stereo separation. Today I will explain what does the stereo separation represent. First, it is a great way of creating harmony in music.

A well-done stereo separation can create an awesome feeling, and in this article I’m going to show you how.

Before that I would like to tell you what does stereo mean. Music is made for people, and because we have two ears the sound comes from two directions. This gives you a lot of possibilities. By using the stereo concept you can simulate a lot of spaces in the mix.

Why do you thing that speakers and headsets have at least two emitters? It’s to allow the sound to be transmitted through two channels.

The method of transmitting a sound through two channels is called stereo. Basically, when you listen to a song, you receive sound from two directions, these being left and right. This is a very simple concept and I’m pretty sure that you got the idea.

Ok, but how can you emit through two channels? You can do this by panning the sound. A sound that has this effect will have volume variations both on the left and on the right side.

To work properly, your speakers should form with your head an equilateral triangle, as you can see in the picture below:

All the distances should be equal. Only this way you can correctly hear the frequencies and differences between the left and the right channel.

Ok, so now you know what stereo is. Let’s move on to mono.

If Stereo is a way of transmitting a sound signal through two channels, mono represents transmitting a signal through a single channel. A sound transmitted through a single channel doesn’t have left/right panning. This type of sound is always in the middle, being emitted with the same intensity from both speakers.

Mono is a lot simpler than stereo. You can’t add effects like chorus, flanger, phaser which affect the two directions of the sound.

Why do we use stereo separation and transmission through two channels? Find out now!

This is another thing that you should know! By transmitting a sound through two channels, you can make it sound like it’s coming from a certain direction. A stereo sound gives a lot more presence, while a mono sound tends to feel faded.

Here is an example:

Mono sound

Stereo sound

This is the same sound, but in 2 variations. In the first one, the sound is centered in the middle(mono) and in the second, there are volume variations between left and right(stereo). You can create various illusions or even surprising effects by using the stereo effect.

What is stereo separation?

In order to fully understand, I’m going to present you the stereo separation. In the mix you can find 3 big frequency areas: the low frequencies, the middle ones and the high ones. Each one has a certain balance limit.

Here are the three areas:

1. Low frequencies: 20 – 200 HZ

2. Medium frequencies: 200 – 2000 HZ

3. High frequencies: 2000 – 20.000 HZ

How should you use stereo separation at certain frequencies?

From 20 to 150Hz you should let the sound on mono, and by mono I’m saying you shouldn’t add any panning.

From 150Hz to 300Hz you can add a little panning, but my recommendation is that it should not go over 25% stereo.

The following area, between 300 and 400Hz you can set the stereo to a maximum of 50%.

After that, between 400Hz and 600Hz, you can go to up to 75% panning.

Over 600Hz you can go to maximum panning. All the frequencies are 100% stereo.

The low frequencies should always be kept on mono. Everything under 200 Hz should be transmitted through a single channel(mono). This means you should add no panning, detuned, or any other volume variation between the left and right channel.

Panning is in fact, a type of balance, and it works like this: when the left side volume increases the right side volume decreases, and the other way around. The volume will always compensate between the left and the right side. This energy that increases on one side decreases on the other.

You might be asking yourself why do the low frequencies need to remain on mono? The answer is simple: The low frequencies have a reduced number of vibrations per second(Hz). This makes them unstable. When you add left or right panning or other effect that changes the left-right volume they loose energy. Music is not an exact science! If in math 3+2 is always 5, in music is not always like that. This is way you should experiment things yourself! It’s not a rule to always keep the bass at 100% mono.

There are producers and sound engineers that use the stereo separation in unique ways. As an example, some producers keep certain instruments on the left side, while they set the others on the right side. This method is used in order to separate the 2 channels.

In a mix there should be a balance between these two channels. Imagine how it would be like if you would keep all the frequencies on the left side? Or how would it be if you would keep all the frequencies on the right side?

It wouldn’t sound right at all! First of all you would hear the entire song in a single speaker. Secondly, there wouldn’t be that effect that your ears believe that the sound is coming from multiple directions. There are many ways of using the panning effect, which I will list in another article. I want to prove you once more that stereo separation is very important.

Here is what an expert told me when I asked him about how should panning be made at certain frequencies:

“Indeed, the trend of using stereo bass came back a couple of years ago. The frequencies and the panning percentage you told me about earlier are right, but there is another trick. If you want to hear your song in clubs, you can’t add stereo on low frequencies, because those sound systems are MONO, and I don’t believe that you want to lose some of the energy of the bass. But if you are using this method on headsets, it sounds awesome, so you can make a compromise, depending on the instrument used and the note that resonates the most.”

In other words, a well-made stereo separation gives a strong feeling, so this is why I suggest you should study this concept.

Mono elements in a mix!

There are 4 elements that should always be kept on mono. The kick, the snare, the voice and the bass are always on mono. Let’s see what frequencies do they cover:

The lowest one is the bass, which can usually be found somewhere under 200Hz. The bass also has some resonance on the higher frequencies, but the highest density can be found on the lower ones, so this is why it should be centered, but not all bass frequencies have to be kept at 100% mono.

I’ve read an article that stated that “There hasn’t been found a way of using a stereo kick.” The kick is another element with a high density on the low frequencies, the lowest one being at 48Hz.

The kick and the bass drum are the lowest elements in a mix, thus giving the most energy. If they give the most energy then they should be always be kept on mono.

The snare is another drum with high density on the low frequencies, which should be kept under control, so don’t add any panning to it either.

Finally we are speaking about voice. It seems that we are using the same technique as well when it comes to the human voice.

The human voice can usually be found in the low-frequency area, especially the male voice, which is one octave lower than the female one.

The white noise should be kept on mono. Being a background effect we don’t want to highlight it. I’ve also started using the mono effect on the clap. Even some drums like the toms are in the same category.

Mix elements that should be kept on stereo!

Let’s see what elements do need balance in a mix.

You might say that the high frequencies should be panned more. This not always true. It depends on the structure of the sound and the context! The context represents where a sound is being used. I will speak about this in a future article, because it’s an important concept. The lead (the main sound) should be panned, but not very much. Sometime it depends on the sound density as well.

A sound which is somewhere between the low and the medium frequency area shouldn’t be panned that much. The chords can be found somewhere lower than the main sound, so they should be panned even less. The hats and the hi-hats should have a little panning, but I usually keep them on mono. I have no reason to highlight them.

I add some panning to the pads though, even though they are background elements. There are some music producers that keep the pads on the left.

How can you easily use a stereo separation technique?

By having so many frequencies in a mix it would be insane to work with every single frequency. In other words, you use a VST that controls the percentage of panning.

This is not always an efficient method. Keep in mind that a preset always changes the note. The sound rises and lowers on certain notes.

When you are at C6 the frequency is over 500Hz. You should increase the balance at the same time. When you go to C5 you need less panning, so in order to make things as good as you could possibly make them you should change the percentage of panning depending on the note. It certainly is some extra work, but if you work hard enough, it will pay off.

Another way of doing this is by using plugins designed for mastering. A good example is iZotope Ozone. This has some functions that you can use in order to control the stereo separation on certain frequency areas.

https://www.youtube.com/watch?v=EaLnSaN0ukE

As an example, if you use the lower frequency area, between 20 and 200Hz you can control the panning percentage. After that, you can set a different panning for sounds over 300Hz. There are a lot of options when it comes to controlling the sound output.

I believe that you’ve learned a lot of things from this article, and I hope that you will use everything that you’ve learned today in your projects as soon as possible. If there is something unclear, then don’t hesitate in leaving a comment. Good luck finding your inspiration!

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