Sonar 5 Prod. Pitch bends. The range of the pitch bend in Sonar is form 8192 to minus 8192. Useless to know until there is some relationship between that value and the frequency of the note(s) involved.
Is there such relationship? Suppose I have middle A=440 Hz and I want to make it 438.5 Hz. What is the value of the pitch bend? Please explain also.
Pitch bend is basically a really special midi controller. As you know, most controllers have values from 0 to 127. This is 2^7, or in terms of data flow, 7 bits of resolution that it can measure. When midi was first conceived, the designers wanted higher resolution on pitch bend to avoid any stepping or zipper effects as you went between pitches. So, they used two sets of midi controllers in a MSB-LSB configuration (most significant bit/least significant bit) to send 14 bits of resolution. 2^14 is 16384, which is what you'll get if you multiply 8192 by two for the positive and negative halves.
The middle value of 16384 registers as no bend, but MIDI can't do negative numbers, so Sonar handles the +/- for display purposes.
Pitch bend can be programmed to span however many notes you want, so it is not possible to correlate the number with absolute values. I ran the numbers based on equal temperament and a pitch wheel value of 2 (a full step upwards and downwards), and I believe you'll want to tune A440 to -477 on the bend for it to be close to 438.5Hz.