Stereo and mono

Mono comes first, stereo is the cherry on top#

As a mastering engineer I get sent mixes all the time that cave in when you hit the mono button. Elements disappear, or start sounding phasey, like someone left a flanger on. I tell the artist, and the answer is: "I don't care about mono."

Mono is very important even nowadays, perhaps more so than when everyone listened on a hi-fi, because people now listen on all sorts of things that could well be mono. And if you want your mix to sound massive in a club and translate on as many systems as possible, you need solid mono compatibility. Mono compatibility must be king in a mix. Stereo should be the cherry on top.

Mono checks and the low end#

I'd always check a mix in mono. Today it's not necessarily about "how do I make my mix wider". It's about spotting what is too wide. Wide sub-bass is especially critical, because it can collapse or vanish in mono and the bass simply drops in level.

A standard correlation meter can fool you into thinking the subs are fine, as it doesn't show you correlation in a frequency specific way. That's exactly why Dogma has a unique spectral ribbon correlation meter and a mono button.

Fake stereo sounds broken, even in stereo#

If you take a mono sound and flip the polarity of the left channel, suddenly it is super stereo. A weird stereo. It feels like your ears popping on a plane, or going through a train tunnel, some pressure change or fakeness. Stereo-widening plugins often give you the same kind of fake stereo. Anything out at the sides of the stereo image chart disappears or drops dramatically in mono, and the mix can crumble.

But to me it doesn't even sound good in the first place. People hear it and think, "Wow, it's so wide." No. It sounds strange and broken in a bad way. The same goes for widening a mix with big side boosts on a mid/side EQ: if you hit mono, it can fall apart. Mid/side and left/right control are genuinely useful tools in sound design, mixing and mastering, but I'd use them with a reason; more under EQ.

Width comes from contrast#

A mix that is wide all the way through can be technically wide on paper and psychoacoustically narrow. Picture a super-wide synth pad playing through the whole song: everything swirly, no focus, like your eyes have glazed over.

The way to a big stereo image is usually contrast: keeping a lot focused down the middle, and occasionally, transiently, having things come out to the sides. If you go from a narrower verse into a chorus that is rich in the stereo image, the chorus sounds far bigger, because you heard it open up. Haas delays, reverbs, doubling and stereo pads are all fine for that, as long as they don't cave in in mono.

Panning is mono-compatible, even for bass#

Panning a mono source off to one side is 100% mono compatible. If you sum the two channels, it is all still there. That goes even for bass. On a These Hidden Hands track I panned mono sine-wave basses around, and it makes a really interesting stereo image with nothing out of phase.

Panned bass, as opposed to out-of-phase bass, can even be cut to vinyl to a degree. Out-of-phase stereo bass can be cut too, it's just less safe, because the needle can jump out of the groove.