Modular Diary – 024

Scratch the measurements from the last two days. I’ve been puzzled by the frequency readings I’ve gotten in Audulus – made using the Mic (External Input) 1 and ZeroCross nodes. (Calculating the deviations in cents was also done in with a little patch using the Audulus Hz2o (Hz to octave) module.)

I found a little tuner app that displays deviations in cents nice and clearly, and tried making some measurements with it directly via my iPhone’s microphone. I could set the ODDYSEi master tuning back to 440 and have the frequency register as a perfectly tuned A4 on the app – which is what one whould expect. The ODDYSEi Equal tuning matches equal temperament perfectly according to the tuner – which makes sense, also aurally! It turns out that Analogue tuning is calibrated to a near perfect A3 (220Hz) and gradually gets sharper as one moves up over the next 3 octaves. Inversely, moving down gradually gets flatter.

ARP ODDYSEi Analog tuning deviations in cents over 6 octaves:

A1 A2 A3 A4 A5 A6
A -39 -30 -1.2 4.8 10.6 16.5
A# -32 -7 -0.7 5.2 11.4 17.1
B -29 -12 0.2 5.6 12 17.6
C -15 22 0.5 6.2 12.4 18.2
C# -47 -19 0.9 6.9 12.9 18.8
D -44 -14 1.2 7.2 13.3 19.3
D# -19 -6 1.7 7.9 13.8 19.1
E -40 -5 2.4 8.4 14.3 20.4
F -30 -4 2.8 8.8 14.9 20.8
F# -10 -3 3 9.2 15.4 21.3
G -7 -2 3.8 9.8 15.8 21.5
G# -17 -2 4.2 10.2 16.1 22.1

(The measurements for the lower 2 octaves fluctuated a lot and were therefore more tricky to notate precisely.)


  1. Feeding the ARP ODDYSEi in via AudioBus

Modular Diary – 024: Scratch the measurements from the last two days. I’ve been puzzled by the frequency readi… rdgr.me/u/17ujdih

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Rudiger Meyer is a composer interested in the play between traditional concert music and new media.


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