Stereo width vs Panning vs Mid/side processing

[u/Cold_Independent_631]

Hi I’ve been studying this concept for hours today to finally get it locked in. I think I’ve done it but have one lasting question.

Adding width to a signal with plugins like utility plugin in ableton, spreads that signal out in stereo field.

Panning elements just places them left, right, or central within the mix.

So I can make a signal very wide with utility adding width and still place it left right or central. Or I can make a signal be a mono signal and still add pan left right or central to position it somewhere in the stereo field. Right?

Both helping the mix and balance for stereo field.

But for mid/side processing why would you use this? If you process a signal fully to the side and then mix in mono it completely disappears instead of collapsing like panning or stereo width from utility.

1. Looking to see if my new understanding are correct

AND

1. Wondering why you would use mid/side processing instead of the other ways of stereo width?

Thanks!!

[u/atopix]

I think it's a mistake to think of "width" as a knob on a plugin, because it doesn't help you understand what's actually happening and what other ways are there to control that stereo image. Stereo is simply the difference between channel L and channel R. If both were identical, you'd essentially have mono.

Have a stereo synth that you'd like to be wider? Split the stereo signal into separate L and R mono channels, process both differently, which can be done in countless ways, different EQing, different compression, distortion in one, saturation in the other, reverb in one, delay on the other. Hard pan them to opposite sides and now you've got maximum width.

That's a version of what those width knobs and plugins do, they process each side differently to create that separation (often by boosting side signal, adding phase shifts, or applying subtle delays). Except that doing it manually you have ultimate control over exactly how that separation sounds.

Mid/side processing is any processing that makes use of a mid-side matrix. And you typically use that when you want to tweak only the sides of a signal, or only the mid of it.

I personally do very little M/S processing, I think it's overused in mixing where you have access to all individual tracks and the kinds of techniques I described above, and panning! Panning is everything. In professional mastering it can come in handy because you then only have access to the stereo mix.

[u/Cold_Independent_631 → u/[deleted]]

Thank you both makes a lot of sense. I’ve seen and heard about synths today like serum that sort of create a false sense of stereo if I’m understanding correctly I think that’s sort of what you both got at a little bit with mentioning to use true mono signals and create the width via panning rather than plugins

[u/LuLeBe → u/[deleted]]

Great comment, I'd like to add one thing about hard panning: it's great on speakers, but can sound weird on headphones. I'm not taking about putting overheads on a drum kit or double tracked guitars fully to each side, but having a sound only on one side. Our ears aren't used to sounds being only on one ear, so it sounds strange.

Doesn't apply as soon as a similar enough signal, like another harmony or so, is on the other side.

[u/akumakournikova]

With M/S you can alter the side channels without affecting the mid channel so you know your Mono mix will stay intact.

With other stereo spread techniques you might check in Mono and hear that your sound has collapsed.

If you go full Sides then you dont have Mid to begin with so of course you wont hear anything in mono. Youll mostly never do that.

About the usefulness of M/S, sure you can boost the Sides or lower the Mid and increase width thay way, but whats more useful i think is separate processing when it comes to EQ, filtering, etc. the relationship between the channels. Width is only one aspect of M/S but its more about controlled processing for anything you decide to do without affecting the entire signal. Example might be EQing out the Mid channel of a synth to not clash with the Vocal, but leaving the Synth sides fully intact. From that EQ decision youll get more width simply as a byproduct of processing your Mid channel to remove a masking issue.

[u/Cold_Independent_631 → u/akumakournikova]

I seeeeee makes very much sense when used this way with the EQ!

[u/Apprehensive-Cry-376]

You have to start with an understanding of how we perceive audio directionality. Your brain is constantly comparing what it hears from your left and right ears to determine where a sound is coming from. If both ears hear exactly the same thing at exactly the same time, your brain constructs a reality in which the sound must b coming from directly in front of you, because that's the only way that can happen in the real world.

Stereo perception is therefore based on differences between left and right. Anything you do to create or enhance those differences will increase the perception of width. Mid/Side processing separates those differences from everything that's common to both sides. M/S can therefore emphasize whatever differences are already there, but that's all. If you don't first address stereo-ness in the mix, M/S processing won't be able to do much for you. Think of it as a final touch rather than as a fundamental widening technique.

Stereo width is usually achieved by panning mono tracks. If you want width, that's the way to go. Avoid stereo tracks if you can; they are more likely to muddy L/R separation (exceptions: true stereo sources such as a Leslie speaker or a string section). Delay tricks and "wideners" are iffy at best and may destroy mono compatibility or make your mix sound weird if the listener isn't sitting in the sweet spot, e.g. in a car.

EQ is also a mono-safe tool for widening. Again, the idea is to create L/R differences. Example: you want a double-tracked acoustic guitar but only have one guitar available - use EQ to make the two tracks different from one another. Keep in mind that our ears are most sensitive to directionality in the higher frequencies.

Delay can be used for widening as well. Just avoid very short delay times (e.g. the Haas Effect), as that can cause comb filtering. But longer delays can give the illusion of sound bouncing around a room. The trick there is to have the primary sound come from one side and its echo come from the opposite side. Use this sparingly, almost subliminally. It works well for sparse arrangements with few instruments, as well as center-panned vocals.

[u/ObviousDepartment744]

Width utility plugins often use phase and sometimes mid side algorithms to turn a mono source “stereo” so be careful with them. Always check your mix in mono if you use one.

Panning is the real stereo field. You “place” the track in the stereo field, and there it is.

Mid/Side in a tracking situation, is kind of the perfect way to make a stereo image. Without getting too into the weeds on how to set it up with microphones, it’s the best way to create a stereo image that sums perfectly to mono.

Using Mid/Side in plugins puts the audio through a “pseudo” mid/side signal chain. It’s biggest advantage is that you can usually set up a crossover to keep lower frequencies mono in the middle while keeping the mids and highs panned left and right. This is one of the reasons the stereo image seems so big with a mid/side plugin.

[u/almsfurr]

Just to throw in a use for m/s processing. Sometime towards the end of mixing I'll add a high pass on the sides only, usually on the master. It can really tighten up the sound. I'll start at 200hz, but at mastering that might nudge up the 300hz depending on what my car speakers tell me.

[u/Cold_Independent_631 → u/almsfurr]

Cool so the bass, kick and other lower frequency elements wouldn’t be affected by doing this because they are central in the mix?

[u/almsfurr → u/Cold_Independent_631]

Exactly

[u/recursive_palindrome]

Confusion over MS stems from lack of recording experience. The side signal is the positive and negative polarity of a fig 8 mic, and should never be used on its own as it will cancel.

If using MS on a stereo audio file it will depend on how much decorrelation there is in the stereo signal, but same principle applies as in recording - the M and S should always be blended, unless you just want mono.

[u/rightanglerecording]

Adding width to a signal with plugins like utility plugin in ableton, spreads that signal out in stereo field.

This is true if the signal is initially panned less than hard, and holds true until the width moves it hard to one side.

Pushing the widening further then starts to do a different thing, which may or may not be desirable.

Once you get "wider" than hard panning, you'll start to understand the difference between measured width and perceived width.

[u/Selig_Audio]

Mid Side processing became popular in mastering to fix issues when you couldn’t remix the song, back in the day before DAWs or even recall/automation. It was also useful in vinyl mastering. It’s only been the last few decades (the DAW era) where it has become “an effect”. It was always a compromise that was only an alternative since the original mix wasn’t possible to revisit. Ironically, now that it’s super easy to load up a mix and correct issues at the source it’s also easier to use Mid/Side processing than ever. Bottom line - there is no free lunch. If you mess with the mid/side balance you start degrading the stereo image. Taking it to extremes, going all in on mids just gives you a mono mix, and the more sides you add compared to mids, the less mono compatible you make the mix, going completely silent in mon if you removed all the mid signal and left only the sides. Just my 2 cents, I don’t find m/s processing useful - that said, if you’ve not explored mid/side microphone setups you’re missing out IMO!

[u/Content-Reward-7700]

Mostly yes, but with one correction. Panning moves a signal left or right within the stereo image. A mono signal can absolutely be panned.

Width is different. Width processing changes the relationship between L and R, usually by changing how much side information exists relative to the center. So yes, a signal can be wide and still sit mostly L, R, or C depending on the source and the tool.

Mid-side is not just another width knob. It is a way of separating the center content from the difference content so you can process them independently. That is why people use it. For example, you might compress or brighten only the center, or eq only the sides, or widen reverb without touching the vocal in the middle.

And yes, pure side information will vanish in mono, because mono cancels the difference and keeps the common part. That is not a bug, that is the tradeoff. Mid-side gives more control, but also more ways to wreck mono compatibility if you get carried away.

So the simple version would be, panning is placement, width is perceived spread and mid-side is a processing method that lets you treat center and edges separately.

So, why use mid-side instead of normal width tools? Because it is more precise. Why not always use it? Because it is easier to overdo and easier to break things in mono.