A bass that disappears on the phone
Your mix sounds full on your monitors. You send it to someone who plays it on a phone speaker, and the bass is not quieter but simply absent. You open an EQ, lift the low region, and on your own speakers it becomes a boom while the phone still plays back nothing. You turn the boost back down and try more level instead. Same outcome.
The problem is not your setting but what an EQ can do. An EQ changes the level of frequencies that are already there, and what a small speaker cannot reproduce stays inaudible. To make a bass exist on such a system you need something that adds energy in places where nothing was present yet: higher components that are reproduced and that your hearing recognizes as the same note. That is exactly what a nonlinear processor does.
What you learn in this chapter
- You recognize the difference between linear and nonlinear processing, and know why only the second produces new frequencies.
- You connect the shape of a transfer curve to the kind of harmonics that comes out of it, and to what you hear.
- You understand why distortion changes the spectrum and the peaks of a signal at the same time.
- You distinguish saturation, overdrive, waveshaping, clipping, distortion and exciters functionally instead of by product name.
- You explain aliasing correctly, hear it yourself and judge when oversampling does and does not help.
- You dose distortion with a level-matched workflow instead of by a feeling of loudness.
Who this chapter is for
For everyone who mixes or produces and notices that tracks sound tidy but lifeless, that a bass or a voice does not hold up on small systems, or that a track becomes fatiguing after adding "character". You do not need expensive plugins: every DAW has at least one saturator, clipper or amp-style effect, and the exercises work with a tone generator, a bass and a drum loop. Concepts about sample rate, Nyquist and peak versus average levels that you are missing can be found in the free intro lessons of the earlier modules.
The core idea in one paragraph
As soon as the output of a process is no longer directly proportional to the input, new material appears: harmonics on top of the existing tones, and with several tones at once also combination tones that are not musically related. That same curvature flattens peaks, so you always change the spectrum and the dynamics in one move. In the digital domain one restriction is added: anything above the Nyquist frequency cannot exist and folds back as aliasing. Once you see those three things together, you understand why saturation can make it sound as if something was added while nothing extra was played, and why the same intervention turns into a mess at too much drive.