I feel like I can hear beat frequencies in the 12TET chords that I don't hear in the JI chord examples.
Anybody else hearing that? Or is that my imagination?
Anybody else hearing that? Or is that my imagination?
We don't even have to listen to the audio examples to know that yes, ET chords produce beat frequencies. This is an artifact of the non-integer relationships created in ET chords that don't exist in the JI examples.
A piano will produce similar beat frequencies when playing a perfect fifth. Some ears are more sensitive to hearing it than others.
It's hard for me not to think of the electric guitar in this context. I love the purity of an acoustic played in a plangent tone like Django. But the incredibly rich spectrum introduced when an amplifier saturates and tons of additional harmonics and subharmonics that aren't supposed to be there gets introduced -- that's it own kind of excitement. Like falling into an abyss aurally.
That's why it sounds weird, because both of the new tones will almost never be harmonically related to the input signal.
Signals tend to sound "better" (richer harmonic content) when they have fuzz added. Convolution reverb is a great example of how mixing a noise sample into any source signal increases its apparent depth or richness.
Some saturators do the same thing.
Others distort the signal by boosting selected harmonics (making the waveform more square-like or more sawtooth-like for example, which is not the same as noise and has a different sound).
Clipping the signal by requesting amplitudes beyond the available range is another way to add "cruch" (noise) to a signal.
The actual implementation will vary per device but overall we like our sounds cut with a bit of noise.