6 Replies Latest reply on Dec 2, 2007 4:45 AM by (Peter_K._Larsen)

    subharmonic synthesis

    Level 1
      Hi,


      subject header says it ...


      Kind regards

      Peter Larsen
        • 1. Re: subharmonic synthesis
          MusicConductor Level 3
          Um, Peter, was that a question?

          I've done this by using the FFT filter to isolate an octave's worth of sound and using the Stretch function -- with a low splicing frequency -- to drop the filtered sounds an octave, then added this low low bass back into the mix. Of course the subject material and desired result may negate my simple technique.
          • 2. Re: subharmonic synthesis
            SteveG(AudioMasters) Level 6
            >Um, Peter, was that a question?

            Looks like a feature request to me! Strange that, considering that it's in the 'feature requests' forum... (hehe!)

            >I've done this by using the FFT filter to isolate an octave's worth of sound and using the Stretch function -- with a low splicing frequency -- to drop the filtered sounds an octave, then added this low low bass back into the mix.

            There are a couple of bass harmonic synthesisers around (including a free one, IIRC) that can work quite well with an isolated bass feed that can resynthesise a much 'fuller' sound. The other thing I've tried was a modification of your approach that doesn't use an octave below, but a fifth above for the same purpose - in the same way that a pedal 10 2/3 ft. quint stop works on an organ to produce artificial 32 ft tone from 16 ft stops, only more controllable!
            • 3. Re: subharmonic synthesis
              Level 1
              SteveG wrote:

              >> Um, Peter, was that a question?

              > Looks like a feature request to me! Strange that, considering that
              > it's in the 'feature requests' forum... (hehe!)

              Suprising userbehaviour .... it was a pro pos the guy who wanted "that
              subwoofer effect" but I can envision other possible uses, also in a
              restoration context.

              [old quote omitted]

              > There are a couple of bass harmonic synthesisers around (including a
              > free one, IIRC) that can work quite well with an isolated bass feed
              > that can resynthesise a much 'fuller' sound. The other thing I've
              > tried was a modification of your approach that doesn't use an octave
              > below, but a fifth above for the same purpose - in the same way that
              > a pedal 10 2/3 ft. quint stop works on an organ to produce artificial
              > 32 ft tone from 16 ft stops, only more controllable!

              At a glance that is an enhancent of what was just a search for recreating
              the missing fundamental in high passed stuff.


              Kind regards

              Peter Larsen
              • 4. Re: subharmonic synthesis
                Level 1
                MusicConductor@adobeforums.com wrote:

                > Um, Peter, was that a question?

                It was la suggestion for la french forum ... ah, la forum des suggestions.

                > I've done this by using the FFT filter to isolate an octave's worth
                > of sound and using the Stretch function -- with a low splicing
                > frequency -- to drop the filtered sounds an octave, then added this
                > low low bass back into the mix. Of course the subject material and
                > desired result may negate my simple technique.

                Hmm ... thanks!


                Kind regards

                Peter Larsen
                • 5. Re: subharmonic synthesis
                  SteveG(AudioMasters) Level 6
                  >At a glance that is an enhancent of what was just a search for recreating the missing fundamental in high passed stuff.

                  No, it relies on difference frequencies being generated, and it only really works acceptably well at low frequencies. For instance, if you took a 4ft pipe playing C (126Hz) and another playing G (190Hz) the difference between them is 64Hz - approximately an octave below the C... But the fundamentals of the two pipes used are still there (and have to be) - there's nothing missing at all - you are simply synthesising a new subharmonic.

                  That's also how a so-called 'Acoustic Bass' stop works - it's actually the two ranks of pipes necessary, but on a single drawstop, with the longest being 16ft, but the combination able to produce 32ft tone - after a fashion!
                  • 6. Re: subharmonic synthesis
                    Level 1
                    SteveG wrote:

                    >> At a glance that is an enhancent of what was just a search for
                    >> recreating the missing fundamental in high passed stuff.

                    > No, it relies on difference frequencies being generated, and it only
                    > really works acceptably well at low frequencies. For instance, if you
                    > took a 4ft pipe playing C (126Hz) and another playing G (190Hz) the
                    > difference between them is 64Hz - approximately an octave below the
                    > C... But the fundamentals of the two pipes used are still there (and
                    > have to be) - there's nothing missing at all - you are simply
                    > synthesising a new subharmonic.

                    Which is why it is an enhancement of my enhancement request ... O;-)

                    > That's also how a so-called 'Acoustic Bass' stop works - it's
                    > actually the two ranks of pipes necessary, but on a single drawstop,
                    > with the longest being 16ft, but the combination able to produce 32ft
                    > tone - after a fashion!

                    Ah yes, thanks - I do begin to remember what was said during organ
                    demonstrations, I just plain failed to connect that stuff to this issue.


                    Kind regards

                    Peter Larsen