Pro Audio Files

Train Your Ears Become a Member

5 Effective Ways to Use Mid-Side Processing

Article Content

I’d like to preface this article by saying that I think mid-side processing is a touch overrated. Which isn’t to say it can’t be incredibly useful, but just that it’s a bit fetishized in the audio world.

I’d wager that this is mainly because M/S is less understood and therefore seen as something that engineers who really know their stuff do.

In truth, 90% of a great mix comes from a really solid foundation in basic engineering and really strong decision making.

That said, there is some room for more complex stuff like M/S processing, so this is a list of the times I find myself most commonly reaching for it.

1. The Master Bus

On occasion I will find myself at the end of the mix and I’ll check the mono fold only to find something is amiss.

It’s normal for the balances to change slightly when listening in stereo vs listening to a mono fold. However, we want to minimize this change and ultimately find a mono fold that still sounds great. After all, this will dictate how our mix is received on the majority of club systems, restaurant speakers, and a whole host of other common playback systems.

Mid-side EQ can be a really useful way of correcting small issues that may arise during translation.

If for example we find our low end to be clean and clear in stereo, but a bit blurry or phasey when folded mono, we may have some excess stereo information that isn’t playing nicely together. In this example, a bit of low shelf attenuation on only the sides may be a good fix. Or perhaps we just want that dead center channel to be a bit more prominent and cutting while we listen in stereo. Maybe a mid-only boost in midrange will get that done without totally skewing our balances.

2. Drum Overheads

Drum Overheads are really a capture of the overall kit. They grab not only the crashes, splashes, and ride, but the snare, kick, toms, and hat as well. And with all these components its understandable that we may want to manipulate the balances within the overheads without necessarily depending on the close mics to do it.

We can use M/S processing to rebalance the original overhead capture in a way that’s more favorable to the style of record we’re going for.

I recently did a video where I used M/S compression to reduce the snare level in the overheads while preserving the cymbals. Similarly, if we want to keep the kick sound and low end of the snare present in the overheads, but it’s just too roomy, some low end M/S attenuation on just the side information, or some mid-only boosting, or both, could give us a tighter low end that plays well in the overall mix.

Ultimately, there’s a lot of possibilities here and it really depends on what you want —but M/S can go a long way in getting that stylistically perfect drum sound.

3. Synth Balancing

In EDM in particular it’s not uncommon to have a lot of very bright elements playing together. Very aggressive white-noisey top ends sound great on one synth, but tend to sound not so great when compounded with other bright sounds.

For the most part, I tend to just pick the top end on the synth that I find most compelling and straight filter out the top end on the other layers (like above 10k). However, if we have a hi-hat going and crash cymbals going, and maybe even a bright snare going, sometimes our record can still sound really crowded.


Now, this is splitting hairs a bit, but mid-side ducking can be a really cool way to transparently open up the top end. The FabFilter Pro-MB or WavesFactory TrackSpacer both offer this capability.

The idea would be to place the hats and crashes in the center pan position, and trigger the top end of the bright synths to duck the hats/crashes in the mid channel only. This will retain the top end on the synths, but clear a lane for the hats and crashes to live as well.

Aside from all that craziness, sometimes pulling a little lower midrange up in a synth layer on the sides can help a record sound very expansive.

4. Killer Low End Pumping

On the topic of EDM, in addition to traditional sidechain pumping between the kick and other elements, we can also create a “kill” duck using M/S.

This is a second layer of pumping that effects only the side signal of our wider instruments. This creates the effect of not only the volume of the instruments pumping, but also the stereo field stretching out. It effectively enhances the sense of pumping by adding a second dimension of dynamics.

Mind you, this is a very specific effect and not always appropriate.

5. Sample Manipulation

Often times in Hip-Hop and various styles of Electronic music we find ourselves mixing samples — that is, pieces of already completely mixed records.

The difficulty in this is that those samples were mixed as whole arrangements, and now we’re ostensibly adding more stuff.

In order to rebalance the samples to make sense with other elements in our new record we sometimes have to get creative with the EQ. And that might mean enhancing a specific guitar sound that lives on the left side of the record while avoiding pulling up the snare, or brightening up the sample in general without turning up the hi-hat that’s in there.

M/S can be used to more specifically target what we are trying to accomplish and get more effective results.


Here’s a playlist of some videos with mid-side mixing techniques.

Matthew Weiss

Matthew Weiss

Matthew Weiss is the recordist and mixer for multi-platinum artist Akon, and boasts a Grammy nomination for Jazz & Spellemann Award for Best Rock album. Matthew has mixed for a host of star musicians including Akon, SisQo, Ozuna, Sonny Digital, Uri Caine, Dizzee Rascal, Arrested Development and 9th Wonder. Get in touch:

FREE Masterclass: Low-End Mixing Secrets

Downloaded Over 19,455 times!

Discover how to make your kick and bass hit hard by cutting (NOT boosting) the right frequencies! Plus, more counterintuitive ways to get fuller yet controlled low-end in your mix. Download this 40-minute workshop by Matthew Weiss, now for FREE!

Powered by ConvertKit