Topics / Bitwig Studio / Bitwig Grid / Bitwig Grid Modules / Grid Pitch Modules / Ratio

Ratio

Bitwig Platform

Ratio module panel in Bitwig Grid
Ratio in Bitwig Grid 6.0.6.

A pitch transposer expressed as an exact numerator-to-denominator frequency ratio.

What it does

Ratio shifts a pitch by multiplying its represented frequency by a fraction. This makes octave relationships and just-intonation intervals easy to enter directly: 2:1 is one octave up, 1:2 is one octave down, and 3:2 is a just perfect fifth.

Controls and ports

In receives a pitch signal. Ratio sets a numerator and denominator from the installed 0-to-99 and 1-to-99 ranges, Stereo-ness chooses the processed lanes, and Out returns the ratio-shifted pitch.

Practical uses

  • Build harmonies with exact rational intervals such as 3:2, 4:3, or 5:4.
  • Move a pitch by several octaves with ratios such as 4:1 or 1:4.
  • Compare equal-tempered Transpose intervals with their just-intonation counterparts.

Things to know

  • Ratio changes the frequency represented by the pitch signal; it does not multiply the pitch number itself.
  • Equivalent fractions such as 1:1, 2:2, and 7:7 produce no shift.
  • Installed examples identify 4:3 as approximately +4.98 semitones and 1:4 as exactly -24 semitones.
  • The numerator permits zero according to localization, but the visible result at 0:x needs measurement because logarithmic pitch has no finite representation for zero frequency.

Technical details

No Nitro implementation has been confirmed for this visible module. The behavior is described conservatively from module metadata and editorial research.

For positive numerator n and denominator d, the displayed semitone offset is delta_st = 12*log2(n/d). The raw Grid cable advances by delta_raw = delta_st/120 = log2(n/d)/10, so out = in + log2(n/d)/10. Thus 3:2 gives about +7.01955 semitones or +0.058496 raw. No dedicated Grid Ratio body has been recovered; two automatic saturation candidates are rejected.

Open questions

  • Measure 0:x handling, maximum ratios, rounding precision, modulation behavior, and how the UI treats reducible fractions.
  • Verify Stereo-ness modes, mono cable expansion, smoothing, and non-finite incoming pitches.
  • Check whether ratio changes are calculated at audio rate or updated as a smoothed parameter.

Version and sources

Checked against Bitwig Studio 6.0.6. This page combines Bitwig's module metadata, the existing Grid course and guides, and Nitro analysis where the mapping is strong enough to support a technical statement.

Return to Bitwig Grid Modules or the Grid Modules course lesson.

Also matches: Bitwig Ratio module, Bitwig Grid Ratio, Ratio Grid module