Pitch shifter /Harmonizer
Thread Summary
The user requested an algorithm for a pitch shifter that produces double notes and dry/wet signals, similar to a harmonizer effect. The engineer suggested using the ADAU1701 pitch shift block to multiply the input frequency by 2 and 4, summing the outputs, and passing the audio through a low-pass filter to remove upper harmonics. The user clarified the need for three different notes using auxiliary ADC potentiometers for pitch control.AI Generated Content
Hello,Could you provide an algorithm for a pitch shifter that produces double note sounds, as well as dry and wet signals? In other words, like a harmonizer effect, it should produce sounds at three different pitches when played on an instrument, with potentiometer controls to manage them. This algorithm should be simple for masters like you. Respectfully.
Audio Signal Processors
software
processors and dsp
SigmaDSP Audio Processors
Processors and Microcontrollers
adau1701
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Hello Japon16,
This is actually a difficult problem to solve. This DSP is limited for instructions per sample period making it tough to do this.
What is tough is to find the pitch of the audio coming in. You have to filter to just have the root frequency and not high level harmonics. Then figure out what the frequency is so you could then synthesize a harmonic by multiplying the frequency by 3 or 5 etc.
You could setup some very narrow band filters to then measure the outputs of each filter and rectify it to figure out the level. Then comparing to all the other bands just takes way too many instructions. Others on the forum might have some better ideas...
This is a project I did to show pitch changing but it is geared for eliminating feedback or large fixed reflections.
ADAU1701 Voltage Controlled Pitch Example.dspproj
I am adding this. I may be making this much more difficult than it is. I will think about this for a bit.
I wonder if the pitch shift block was just set to multiply by "2" and then another one to multiply by "4" and then summing all the outputs together?
It would make sense to pass the audio through a LPF to get rid of upper harmonics.
Dave T
First of all, thank you very much for your support. What I want to explain is, think of it like karaoke, using auxiliary ADC potentiometers, each with pitch shifter settings, to get three different notes from the output, like a detune effect. A better example: if the note is low A, the next note coming from behind is high A, and you add the instrument's own dry signal sound to these notes. I hope I've explained it clearly. If you have an algorithm for this, I'd like to see it. I will also take a look at your attached algorithm. Thank you.
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