Stereo, mono compatibility, mid and side channels, width, mono vs stereo…
The world of stereo imaging can be confusing. I know it was for me when I started out.
I couldn’t understand why everyone else’s tracks sounded so wide, and mine so narrow. If that’s your case too, then read on!
In this short guide, we’ll cover everything you need to know to get wide, powerful mixes. Together we’ll look at:
- The difference between mono and stereo
- What are the mid and side channels
- Tips and tricks to use stereo imaging in your mixes
So let’s go! 👇
The Basics of Mono vs. Stereo
First off, let’s cover some basic definitions. Starting off with the concepts of mono vs stereo sounds.
A mono sound is a sound that seems to emanate from a single position.
Think of your smartphone speaker when you are talking to someone for example. Or a small portable Bluetooth speaker:
However, mono can also be duplicated into several speakers. In that case, identical signals are fed to each speaker. This will give the impression of a “single sonic image” emanating from the space between the two speakers.
On the other hand, a stereo sound uses two separate audio channels playing through two different speakers.
These 2 signals can be completely different or have only subtle differences. This is what gives a sense of width and space to a recording:
A majority of modern playback devices use stereo: Hifi speakers, earphones and headphones, gaming headsets, car speakers, etc.
One Step Further: Mid and Side Channels
Now that we’ve covered the basics of mono vs stereo, let’s dive a little bit deeper.
If you’ve explored the world of stereo imaging before, chances are you’ve come across the terms “mid” and “side”. But what do they actually mean? And how do they relate to the concepts of stereo and mono?
Mid/side processing (abbreviated as M/S processing) lets you manipulate the “middle” and “side” information of a stereo signal.
“Mid” refers to the information of a stereo signal that is identical in both speakers.
“Side” refers to the information that is different in both speakers.
Let’s illustrate this quickly. Here I have a stereo drum loop:
Now I am going to remove all the “side” information, i.e. only keep what is identical in both speakers:
And now let’s remove all the “mid” information, so we only keep what is different in each speaker:
We can notice that the core beat is mostly mono, meaning we have the same information in both speakers. However, the highs and the reverb have been processed in such a way that they live mostly in the side channels.
Note: removing the “side” information is different than collapsing to mono! Although removing the “side” information also gives you a mono signal, the result is a net loss of information. Collapsing to mono on the other hand converts all the information available into a mono signal, without loss of information.
Why is this useful? Well, accessing the mid and side channels gives you a whole new range of options when processing sounds. One example is EQ’ing:
In this example, I am low-cutting only the side information and leaving the mid intact. M/S processing basically gives you much more freedom to compress, EQ, and further process within the stereo field of your signal.
Beginners Beware Mono Compatibility!
Finally, let’s quickly talk about mono compatibility.
Mono compatibility is the process of checking that your track still sounds good in mono.
“Why is this important”, I hear you ask. Doesn’t everyone use stereo headphones or speakers? Not exactly. How many people have you seen playing music from their iPhone speaker, or a lonely Bluetooth speaker? Yep, that’s mono.
But more importantly, is if/when you play your tunes live in a club. Clubs have multiple speakers, on different floors, with people facing every direction possible. Stereo speakers would be completely useless, or downright sound awful:
This is why a majority of clubs have their sound installation set to mono.
For all these reasons, you need to make sure that your track sounds great in mono too. To do this, simply download the free SPAN plugin. SPAN is a spectrum analyzer that also provides a stereo correlation meter:
A reading of 1 means your sound is perfectly in phase. So it will sound great in mono. But a reading of -1.00 means your waveforms are out of phase.
In general, try to aim for something as close to 1 as possible.
Staying around an average of 0.75 is a good rule of thumb, as the mix can change over time. So start by putting SPAN on every Bus channel you have (Drum Bus, Pads bus, Vocals bus…) and check for issues.
Alternatively, you can also get in the habit of converting your track to mono while mixing. Does it still sound good? Have any elements completely disappeared from the mix? If so, you will need to go back and make sure they have enough mono information.
Want to learn more about mono compatibility and phase cancellation? Right this way!
5 Stereo Imaging Tips and Tricks 👊
These tips will help you achieve that width you’re looking for in your mix – especially if you’ve got a lot of mono sounds.
Focus on the Mid below 200Hz
As we talked about earlier, mid/side processing opens up a world of possibilities. The most frequent application though is mid/side EQ’ing.
For this, you will need a plugin that offers mid/side options. In Ableton Live, you can use EQ8. FL Studio unfortunately doesn’t offer a stock plugin with mid/side EQ’ing.
Here, I am using Fabfilter Pro-Q 3:
By default, any new EQ point you draw will be set to “Stereo”. Simply select “Mid” or “Side” to only EQ the Mid or Side channel.
As a general rule of thumb, you want anything below 200Hz to be dead center. This means you can safely remove the side information of anything playing in that frequency range. This will remove muddiness and make your track sound more focused when it is collapsed to mono.
Boost the Sides in the High Frequencies
You can also use Mid/Side EQ’ing to boost any given frequency.
One common application is to widen a mix by boosting the highs on the sides.
This will create an even larger sense of space in your mix, but more subtly than with a stereo widener plugin:
Have a listen here and see if you can spot the difference:
Remember, with mid/side EQ’ing, we are aiming for subtle mix improvements. Removing congested areas of the mix, adding clarity and space etc.
Widening Your Snare for More Impact!
Finding the right level for your snare can be tricky. Boost its volume too much and it can overpower the mix. But lower its volume and it disappears. What gives?
This is where stereo imaging can come in handy. Add a layer to your main snare: a clap, a snap, or anything with high-frequency information. Then, widen its stereo image with a dedicated plugin or by boosting the sides:
Here, I am expanding the stereo image of the clap in the second half of the loop with the free plugin Wider. When doing this, make sure you are not expanding any low frequencies!
Recommended: The Haas Effect – How To Make Any Mix Sound Huge
Switch between Mono and Stereo for Better Builds
There are a million tips and tricks for better builds and drops on YouTube.
The most common trick is to high-pass your entire mix during the build-up phase. This allows you to properly “drop that bass” when the drop hits. Another one is to lower your mix by just a few dBs during the build. When the drop hits, you turn the volume back up, giving some added impact to the drop.
But you can also use the mono and stereo concepts to your advantage here! During the build-up phase, slowly collapse your mix to mono. You don’t need to go 100% mono here. Simply removing some stereo information, then re-introducing it during the drop will give it more impact:
In Ableton Live, just slap a Utility plugin on the mix bus and slowly decrease the Width. This will narrow your mix towards mono.
In FL Studio, you can use the “Stereo Separation” knob to merge the signal to Mono:
Widen Your Effects
One trick I love to use is to widen the stereo image of my reverbs. To do this, you need to have your reverb set as a SEND track:
Have a listen:
What I love about this is that I can increase my reverb’s presence without boosting its volume. This trick also works great on hats, shakers, and other percussive elements. If you have some reverb on them, try widening their stereo image to give them more space.
Need a guide on bringing your reverb skills to the next level? We have you covered!
That’s a Wrap!
That’s it for this guide on mono vs stereo! If you want to dive deeper into stereo, check out this video from Aden:
Hopefully, you now have a better understanding of all things mono and stereo, and how to use them to your advantage. Did I miss out on anything? Let me know at [email protected].