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> On 12/07/2023 11:45 AM EST Russell Wedelich <[email protected]> wrote: > > > No splicing required: https://urldefense.proofpoint.com/v2/url?u=https-3A__www.semanticscholar.org_paper_Low-2Dlatency-2Daudio-2Dpitch-2Dshifting-2Din-2Dthe-2Dtime-2Ddomain-2DJuillerat-2DSchubiger-2DBanz_9fa827c688688157cc93ec9b296f24a45c6dfdf6&d=DwIFaQ&c=009klHSCxuh5AI1vNQzSO0KGjl4nbi2Q0M1QLJX9BeE&r=TRvFbpof3kTa2q5hdjI2hccynPix7hNL2n0I6DmlDy0&m=KYMvh0wc_c25BhCjzc9f6koCuOMMvp42ThAGGy-qM0jk3MMMDQ6daqhCrP0LdEe4&s=J83EkoNPjYpu7xaT1te8J1QUJKEqRAMrD99LE6rt414&e= > > It's all IIRs, HIlberts, oscillators, e.g. a large bank of narrow band frequency shifters. It could be done with all analog right? Key word I used is "silly" b/c that's what it would be. > Hi Russ, There are so many goofy things about this. In 1992, before I did my first pitch-shifter for the DSP4000, I did a Hilbert-transformer-based frequency shifter. Gil was so excited about our new "glitch-free pitch shifter" and we had to remind him "*frequency* shifter" and the response was "what's the difference?" Richard, being a ham operator, was sorta into it. Ken and I discussed this multiband frequency shifter but this thing leaves holes in the output spectrum if you're upshifting and, for downshifting, it either has holes in the input spectrum or there is overlap in the output spectrum. If there is overlap, then the same sinusoid gets shifted by two different frequency-shifting bands and will get shifted to different frequencies. I just don't think it's a good idea. For me, the purpose of a frequency-shifter is to slightly detune the harmonic partials to slightly non-harmonic frequencies to sorta fatten up the sound. It might help for chorusing. Or just for another, sorta surrealistic spacey effect that sounds like Single Sideband (SSB) that's not perfectly tuned. I just think, for pitch shifting, that it's important that the frequencies of every sinusoid are *multiplied* by exactly the same ratio. And then detune the harmonic partials afterward, if you want that effect. - robert > > On Tue, Dec 5, 2023 at 9:22 PM robert bristow-johnson <[email protected]> wrote: > > Still I wonder how you would make good splices. Even with lotsa overlapping grains, some are gonna be way outa phase and makes a glitch. > > > > It just seems to me that some kinda analysis needs to be done to decide where to splice to and when to start. > > > > I knew about the spinning heads on tape but never saw any of them. > > > > Powered by Cricket Wireless > > > > ------ Original message------ > > From:Russell Wedelich > > Date:Tue, Dec 5, 2023 8:15 PM > > To:[email protected]; > > Cc: > > Subject:Re: MUSIC-DSP Digest - 3 Dec 2023 to 4 Dec 2023 (#2023-67) > > > > “(Like in pitch shifting. But I'd like to see you do decent pitch shifting with a purely analog device.) “ > > I once had a silly idea for an all analog (well digitally controlled) Rollers type Pitchshifter, frequency shifting approximating pitch shifting in many bands. If would be sooooo expensive! So many opamps. > > Long time reader, first time replied (maybe). > > -Russ > > > On Dec 5, 2023, at 3:23 PM, robert bristow-johnson wrote: > > > > > > (Like in pitch shifting. But I'd like to see you do decent pitch shifting with a purely analog device.) > > -- r b-j . _ . _ . _ . _ [email protected] "Imagination is more important than knowledge." . . .
