Data AcQuisition And Real-Time AnalysisScope - Spectrum - Spectrogram - Signal Generator
Software for Windows
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Spectrogram Pitch Track can handle input frequencies up to half the sample rate. Modern sound cards have sample rates of 48 kHz or higher, so the upper Pitch Track limit is 24 kHz or more. However, MIDI only allows notes up to about 12.5 kHz (MIDI note number 127). To handle higher frequencies with Pitch-to-MIDI, you can shift them down by octaves with this control. (Each octave shifted down cuts the frequency in half.)
You can tell if you need this by using the MIDI note number mode of the Pitch Freq Axis (Notes/Freq/MIDI) control: If you see pitches detected at MIDI numbers above 127, you need to shift down. For example, if you set +/-Octave to -6, then MIDI number 132 (C10 = 16744 Hz Hz) will be shifted down by 6 octaves (72 notes, or frequency divided by 2^6 = 64) to 60, which is Middle C at 261.626 Hz.
By shifting ultrasonic sounds down into the audible range, this can allow you to detect bats, insects, steam leaks, or defective machine parts that might otherwise be overlooked. You will probably want to use a continuous-tone wind or bowed string Instrument (not a piano or guitar), plus Note Bend and Velocity Track to follow the input signal as much as possible. If you set Hysteresis to maximum, Note Bend can track large frequency sweeps without breaking then into multiple notes.
You can also use +/-Octaves with normal musical frequencies to shift the MIDI sound to a different octave. You can shift up as well as down; the range is +/-16 octaves.
Note: This control does not affect the display, only the conversion of pitch to MIDI.
PitchOct=-2 shifts the notes going to the Pitch-to-MIDI converter down by 2 octaves.
RO=n sets the Pitch Octave to n, where n can be any integer or valid Changes script expression. This may consist of MIDI control values (including RO), random values, current computer keyboard states or mouse position, input or buffered notes, oscillators, or User Variables.
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