What is saturation? (It's not what you think it is)

Further reading
In professional audio, saturation refers to the distortion that occurs when a signal is overloaded and exceeds the capabilities of an audio device or system. Saturation can occur in a number of different ways, such as when a microphone is overloaded by a loud sound source, or when a signal is processed through an effect that pushes it beyond its normal range.
Saturation can be used intentionally as a creative effect, as it can add warmth and character to a sound. It is often used in music production to give instruments or vocals a sense of depth and presence, and can be achieved through the use of analog hardware or digital software.
However, saturation can also be a problem if it is not desired or if it occurs unintentionally. In this case, it can cause the audio to sound distorted and unpleasant, and can even make it difficult to understand spoken words or lyrics. To avoid unwanted saturation, it is important to carefully monitor levels and ensure that signals are not being overloaded.
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I don't think your premise is entirely accurate. Imagine you start with a 1kHz sine tone, push it through a tanh() waveshaper, and get a series of odd order harmonics... 3kHz, 5KHz, 7KHz, etc. You can then make an EQ move in the spectra above your original 1kHz tone and affect the now existent harmonics. The extreme example may be to use a higher order highpass filter around 2KHz... for the thought experiment, we can even simplify this to be an ideal lowpass filter that completely eliminates the original 1kHz tone. We are still left with the harmonics created from our waveshaper.
One more note. The real complexity of the magnetic saturation seems to come from the hysteresis. The output of a hysteresis model is state-dependent. I doubt it is inversible, although I'd have to take a closer look at the equations to say that definitively.
@91JLovesDisney: Thanks for the video, also you sound like Paul McCartney
@teashea1: watched again ----- wonderful again
@notgiven3114: Lame, lame, lame. You use very imprecise and often incorrect language.
@ksteiger: I remember when digital was becoming popular in the 1980s as a recording medium. A lot of people tried to convince me that drums and cymbals sounded better on analog and that digital always made cymbals sound harsh, strident or brash. I knew it was because the analog tape was being saturated and making the hf content "warmer". They were actually objecting to the accuracy of the digital recording.
@AudioMasterclass replies to @ksteiger: This is true. We've all gotten used to the sound of analogue drums. We like it and prefer it to accuracy. DM
@mrnelsonius5631: Some “saturators” change the overall frequency response and some do not. For example, plugins modeling specific hardware can have a low frequency boost, high end roll off: lots of things over just clipping and/or adding harmonic content. I imagine for those that don’t change the frequency response EQ placement is less important. Those that do, it’s probably more important.
@curtgozaydin922: Shoot, I meant said it wrong. I meant to say that saturation implies both things.
@curtgozaydin922: I mean no disrespect and I love watching your YouTube channel… but my understanding in the audio industry and especially guitar, electric guitar, kind of music, amplification world and effects pedals world is that distortion usually implies TWO things happening, both a compression and a distortion. Now the word saturation is supposed to also imply a lesser degree of “distortion”, that is less than the word “distortion” by itself implies. So anyway, I’m not sure if you’re the saying the same thing, but this is my understanding as a previous electric guitar player of years ago (and a current practicing electrical engineer EE now).
@AudioMasterclass replies to @curtgozaydin922: Taking into account your subsequent comment, when an electric guitar distorts it also compresses the sound. In fact, since saturation affects peaks, any kind will cause distortion. I'd have to ransack my electronic theory books but I imagine that perhaps distortion caused by insufficient standing current in a Class A/B amp would only affect the signal close to zero so there wouldn't be compression. I'm sure you know more than me on that. But yes, a distorted electric guitar has less dynamic range and is therefore compressed. DM
@VinnieLeeStudio: So true. Saturation is not only about altering the frequencies, but also the dynamics(transients).
@drrodopszin: Where EQing absolutely makes sense is before clipping. If you clip a bass-heavy drum like a kick drum the clipped low frequency start to have a "farty-cloudy" sound, losing punch and clarity. The trick is to have an EQ before clipping turning down a bass and another to turn back up the bass afterwards (Dan Worrall has the emphasis-deemphasis video on the matter).
@MacinMindSoftware: I never thought of or used the term saturation for harmonic enhancement so going back to your previous video to hear that was new to me. My understanding of harmonic enhancement was to take a frequency and make a duplicate of it at double and triple, or 1/2 etc. of the original, I thought. That's what the term means in RF harmonics--2nd, 3rd harmonic, etc. Good learning nonetheless.
@AudioMasterclass replies to @MacinMindSoftware: Saturation is one way of producing harmonics, which as you say are whole-number multiples of the original frequency. Of course it gets more complicated than that with intermodulation distortion, and analogue tape which adds non-harmonic frequencies due to scrape flutter. DM
@RocknRollkat: Hello DM,
Yes, saturation is not the same as boosting frequencies.
A spectrum analyzer will bear this out in no time flat.
I've developed several saturation plugins, the spectrum analyzer is indispensable.
And as you know, tubes, transistors and FETs saturate as well, with different harmonics being produced, for a slightly different sound.
Best regards,
Bill P.
@1622steve: Are transformers a part of "tube sound"? In addition to saturation, there's residual core magnetization. There will be hysteresis.
@Yoda8945: Your explanation is very complete as to Plug-ins in a DAW.
Saturation as I know it is the limit of analog tape to hold more magnetism. The result is generally a loss of high frequencies and a soft, somewhat pleasing emphasis of the lows and compression of the dynamic range. This is of course, distortion, but not all distortion sounds bad.
@AudioMasterclass replies to @Yoda8945: Not all distortion sounds bad, I agree. What would Jimi Hendrix be without the distortion of his Marshall amps? DM
@jkgrooves: The more interesting question to me would be why do we like it and find the sound pleasing it all
@daa2622: the colours on the video are so.. vibrant.. pleasant?? theyre really good! keep it up!
@TheGoatBeats: So one can assume that “saturation“ is a marketing thing most of the times? Should they be named “Harmonic enhancers” instead of “saturators”? Can real saturation even be “modeled” for the emulation plug ins?(strips etc)
@WassupFred: Very cool way of explaining it
@Zenvo-uu9tm: Thank you Mr
@mcpribs: Fascinating…though I will continue to use the term, more often than not, incorrectly. Haha
It’s just such a pleasing word to me. Excellent video, as always! Thank you!
@chaoticsystem2211: i'm back..
@smarthalayla6397: What is saturation? A fancy word for sound clearness destruction.
@oscarmorales-cn3hz replies to @smarthalayla6397: Yes
@huberttorzewski replies to @smarthalayla6397: It's a tool to make the mix more pleasing to an ear, more dense, richer and warmer sounding. When used correctly and not too much of course. Too clean audio sounds boring and not dense enough (you hear inidividual harmonics which is very distracting to an ear and it's very boring sounding at the same time). Too much saturation sounds like the audio is dirty and distorted and it should be avoided also. Somewhere in the middle sounds the best
@C90C60C30: Love the science. Very interesting.
@bassbuzzmusic6681: I found gem finally ❣️
@OctavianMusic: awesome! every video!
@teashea1: very excellent ---- so well done
@cholkymilkmirage4984: fuking amazing. im on board saturation is too loose