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So, in English: A sawtooth is a wave that looks like the blade of a saw. It is pretty close to sinusoidal, so it sounds somewhat like a single tone, but there
by mlyle 3y ago
So, in English:
A sawtooth is a wave that looks like the blade of a saw. It is pretty close to sinusoidal, so it sounds somewhat like a single tone, but there is some distortion and harmonics; not nearly as much as you'd get from a square wave, though.
A synthesizer has an envelope generator, to model how real instruments increase in volume, keep a steady volume while active, and then decay. The envelope is usually multiplied by the underlying waveform, like a sawtooth, to give it these characteristics.
If you have a musical keyboard, pressing a key chooses the frequency of the sawtooth, and the moment that the key is pressed and released trigger the envelope generator and choose its shape.
For the psytrace bass line-- instead of the envelope generator being multiplied by the signal (and controlling its amplitude directly), instead it is used to sweep a filter. How much of the distortion and harmonics you hear from the sawtooth changes over the course of the note and gives the bassline its distinctive sound.
- ecocentrik 3y ago"A sawtooth is a wave that looks like the blade of a saw. It is pretty close to sinusoidal, so it sounds somewhat like a single tone, but there is some distortion and harmonics; not nearly as much as you'd get from a square wave, though." In Fourier terms, a sinusoidal is the fundamental frequency. A square wave contains the fundamental frequency + all odd harmonics. A saw wave contains the fundamental frequency + all odd and even harmonics. No distortion is needed to shape a saw wave and the rest of what you said is inaccurate.
- mlyle 3y agoIt is distorted in the sense that a sine wave that has been put through a nonlinear process -- e.g. clipped to form a square wave; clipped and integrated to form a triangle; clipped and integrated asymmetrically to form a saw; etc. Total harmonic distortion measures the amount of power that you have in harmonics vs. the fundamental wave. A purely sinusoidal tone would have no energy in harmonics; a saw would have 44% of its energy in harmonics. Maybe you're nitpicking and saying that it's not "distortion", but harmonic distortion as a metric of how much energy is in harmonics-- because the primary way we used to get those harmonics is by distortion of a sine wave-- is common lingo.
- ecocentrik 3y agoMaybe I was nitpicking about the use of the term "distortion" (I prefer "transformation"), but I did want to clarify that saw waves are more harmonically rich and complex than square waves.
- mlyle 3y agoYah. I did screw up the comment, in that I had intended to talk about triangles first and then mention asymmetry. The fact that you have second harmonics is what makes saws so useful as a basis function for synthesis.