4 ms·
All right, mister fancypants. I decide to create a sawtooth signal by repeatedly drawing a diagonal line, then a vertical line in my digital PCM sample array.
by SeanLuke 6y ago
All right, mister fancypants. I decide to create a sawtooth signal by repeatedly drawing a diagonal line, then a vertical line in my digital PCM sample array. It looks like a sawtooth when I plot it, but the sound that comes out doesn't sound like a sawtooth: it has lots of reflected harmonics caused by those sharp corners. What is your term for the artifact that I had unintentionally introduced?
- willis936 6y agoAliasing. That isn’t a digital signal.
- SeanLuke 6y agoOf course it's a digital signal. It's a PCM array. If what you mean is "the artifact isn't 'aliasing' until it finally goes through the DAC", my answer to you is: that's a useless and counterproductive distinction. I inadvertently introduced an artifact into my digital signal that I cannot easily remove. That this artifact magically gains a label only once it passes through the DAC is pedantic nonsense that helps no one.
- willis936 6y agoThis is not some useless academic distinction. You are measuring an analog signal. You do not worry about aliasing in all digital systems, even if they are representing something you might typically make into an analog signal. Why would you want a digital square wave? Who knows. But aliasing is not in the digital signal.