What are cents in music and how is it used to detune/tune in synths.

[theblackbelted1]

I can't find any tutorial on youtube about this. All I know is that there are that each note in the octave has 100 cents so 1200 each octave , and they are used to create those saw chords that you hear in a lot of electronic music. In massive when I want those chords I will bring two of the oscillators cents down and one up. But I want to know what's happening when I do this and why it does this.

 

[theblackbelted1]

also , am I out of key if I do this? or am I fine if I just stay on the side closest to the original pitch i was in. for example if I had -0.45 would that be considered my original note still and would -0.56 be considered the the flat version of the original note?

 

[krushing]

Can't say I've ever heard anyone say that there are "1200 cents each octave" - it's technically true, but makes it somewhat more complicated sounding than it is. The simpler way to think about it is just - as you seem to have figured - that each semitone consists of 100 cents. So whenever you want to tune less than a semitone, you use cents. And yes, you're theoretically out of tune when doing this, but in practice subtle detuning just ends up sounding "richer" instead of "off". As for the last part of the question - again, theoretically you're obviously closer to the next semitone if you go more than 50 cents in either direction, but don't think about it too much. Listen to how it sounds.

 

[theblackbelted1]

how in the world do you know all of this stuff. Not just the detuning but everything. I've literally been learning from all of your answers on different posts

 

[Wapiti]

Another viewpoint is 8hz = 32 cents. So say your synth is playing in A440 tuning, detuning each oscillator 32 cents would give you a synthesizer tuned to A432hz.

 

[bandcoach]

Another viewpoint is 8hz = 32 cents. So say your synth is playing in A440 tuning, detuning each oscillator 32 cents would give you a synthesizer tuned to A432hz.

not true: that number will change for each pair of semitones, as the difference in frequency between each pair of semitones is divided into 100 equal parts (even the concept of 8Hz = 32 cents is not supported at the specific example of A=440Hz: 32 cents above A=440 is 8.3712Hz + 440Hz = 448.3712Hz, 32 cents below A-400 is 440Hz - 7.904Hz = 432.096Hz)

for example

A =440Hz
A#/Bb = 466.16Hz

therefore 100 cents between A and A#/Bb = 26.16Hz, and 1 cent becomes 0.2616Hz

G#/Ab = 415.30Hz
A = 440hz

therefore 100 cents between A and G#/Ab = 24.70Hz, and 1 cent becomes 0.2470Hz

now consider the same note pairs one octave lower

A =220Hz
A#/Bb = 233.08Hz

therefore 100 cents between A and A#/Bb = 13.08Hz, and 1 cent becomes 0.1308Hz

G#/Ab = 207.65Hz
A = 220hz

therefore 100 cents between A and G#/Ab = 12.35Hz, and 1 cent becomes 0.1235Hz

now consider the same note pairs one octave higher

A =880Hz
A#/Bb = 932.33Hz

therefore 100 cents between A and A#/Bb = 52.33Hz, and 1 cent becomes 0.5233Hz

G#/Ab = 830.61Hz
A = 880hz

therefore 100 cents between A and G#/Ab = 49.39Hz, and 1 cent becomes 0.4939Hz

This is why it is dangerous to use ideas like 1200 cents in the octave as the cent ends up being miscalculated - in the octave 220Hz to 440Hz this would set the cent to something like 0.1833Hz which is significantly larger than the cent between A=220Hz andf A#/Bb=233.08Hz, 0.1308Hz difference is 0.0521Hz

 

[scrapheaper]

I want to know what's happening when I do this and why it does this.

You need to have some basic understanding of waves.
The scientific word for pitch is frequency, which is the number of waves in one second, measured in hertz.
If the pitch/frequency is higher, which means more waves in one second, so each individual wave has to be shorter. So a wave which is higher in pitch has a shorter wavelength and a shorter time for one wave.

Now, imagine you are playing two waves at the same time, one has a higher pitch and is slightly shorter. They will start out in phase, but the shorter one will 'fall behind' the longer one quickly and then they'll be out of phase and cancel each other out. Then the shorter one will fall behind so far that it comes back in phase again... this is what gives you the pulsating effect, the waves continually going in and out of phase with each other. (To test this, you can take a synth which has phase controls, turn two oscillators onto saw waves and play with the phase knob on one of them When the phase knob is moving, you should hear the same effect as detuned waves)

Beat Frequencies