Audio to MIDI: Why Does the Same Pitch Bend Sound Wider?
Check the receiver's pitch bend range before redrawing the pitch curve. A MIDI 1.0 pitch bend event stores wheel position. The receiver uses its sensitivity setting to interpret that position as a pitch interval.
A one-byte comparison
The two downloadable fixtures in this research folder each contain 55 bytes. Both start MIDI note 60 on channel 1, send the same wheel value of 12288, and release the note at tick 480. The files differ at zero-based byte offset 33. That byte sets the semitone portion of pitch bend sensitivity to 2 in one file and 12 in the other.
The wheel's center is 8192. The stored value 12288 is 4096 counts above center. Under a linear model that normalizes the positive displacement by 8192, this is half the configured range. The model gives a rise of 1 semitone at a 2-semitone range and 6 semitones at a 12-semitone range. These are calculated intervals. The experiment compares saved bytes and does not measure the output of a synthesizer.
Inspect the receiver settings and the event order
Keep a copy of the original export. Inspect the note's channel, the pitch bend value and the receiver's configured range. If the file sets the range with MIDI messages, look for CC 101 and CC 100 selecting registered parameter 0, followed by Data Entry on the same channel. In these fixtures CC 6 carries whole semitones and CC 38 carries zero cents. The messages precede the note and the bend.
If a destination ignores the range message, check its instrument settings and test a short copy before editing the full pitch curve. A retained bend value from a previous clip is a separate diagnosis. This comparison holds the bend value fixed and varies sensitivity.
Reproduce the byte check
Run python pitch-range-fixture.py in the research folder. It writes range-2.mid and range-12.mid, asserts the changed byte offset, and decodes the common wheel value. The fixture uses a single channel, ordinary MIDI 1.0 messages and no rendered audio. It does not test DAW import, plugin compliance or MPE.
Technical references: MIDI Association message summary and MIDI 1.0 Control Change Messages.