Mix Diagnosis: learn to name the problem before you touch it

Before choosing the tool you have to name the problem

Almost all the material out there on mixing explains tools: how a compressor works, what each knob on an EQ does. Very little explains the decision that comes first — the one separating people who progress from people going in circles for three years: faced with a mix that sounds wrong, what exactly is happening and what should you touch?

That skill has a name in every technical trade — diagnosis — and it's trained the same way as any other: seeing many cases and checking your reasoning against the right answer. A mechanic doesn't learn to fix cars by reading the manual for a spanner.

Each scenario describes a concrete situation — the vocal isn't intelligible, the mix falls apart in the car, kick and bass are fighting — and offers four possible interventions. There are 12 scenarios. The useful part isn't getting it right, it's reading the explanation when you don't: the wrong options are written to be plausible, because expensive mistakes in a real mix are never absurd. They're the correct solution to a problem you didn't have.

How to play, step by step

  1. 1.Read the whole scenario before looking at the options. Half the errors come from answering the first familiar-sounding word.
  2. 2.Before choosing, say out loud what you think is happening. That sentence is the diagnosis; the option you tick is only its consequence.
  3. 3.Pick one of the four interventions. None is absurd: they all fix something, and only one fixes what the scenario describes.
  4. 4.Read the explanation whether you're right or wrong. When you're wrong, work out which problem your answer WOULD have been right for: that's what builds judgement.
  5. 5.Scenarios climb through tiers, from Apprentice to Producer, and there are 12 in total.

What each tier includes

Apprentice — 3 scenariosFree
Single-symptom, single-cause problems: a vocal you can't make out, an obvious excess of low end. Here diagnosis and solution almost coincide.
Assistant — 3 scenariosFree
Cases with two competing elements appear. The symptom is in one place and the cause in another, which is diagnosis's first real lesson.
Engineer — 3 scenariosFree
Problems where the obvious intervention makes things worse: compressing what was a frequency problem, EQing what was a level problem.
Producer — 3 scenariosPro
Full-mix and translation decisions: why something collapses in the car, why a master loses on a phone.

Four diagnostic rules that hold in any mix

  • Start with level. A surprising number of problems that look like EQ are balance, and EQing to fix a badly set fader leaves the mix dull.
  • Separate symptom from cause. «The vocal isn't intelligible» is a symptom; the cause might be the guitar, the reverb, the compressor or the vocal itself.
  • If two elements are fighting, decide which one leads first. You don't fix it by raising both: you fix it by making room in one.
  • Before adding something, try removing. The most frequent fix in a mix that sounds wrong is a cut, not a boost.

Frequently asked questions

How is this different from Plugin Quest?

In the order of the question. Here you decide what is happening; in Plugin Quest, which tool to attack it with. In a real session they happen in that order, and skipping the first is what has people trying plugins at random.

Do the scenarios include audio?

They're text and decision: they describe the situation precisely and ask you to choose. The listening side — recognising the problem by ear — is trained in EQ Surgeon, Frequency Drop and Mix & Match.

Why are the wrong options so plausible?

Because expensive mistakes in a real mix are never absurd: they're the correct solution to a problem you didn't have. Obviously bad options would train elimination, not diagnosis.

How long before I notice a change in my own mixes?

Usually the first thing that changes isn't what you do but what you stop doing: the plugins added just in case disappear. That tends to show up after a couple of tiers.

Where to go next

Diagnosis has two requirements and this covers one; the other is actually hearing it, which is what ear training is for. Two cases that come up constantly have their own guides: mixing vocals and kick and bass.