Kenji's K5000 Message Board Digest - Overview K5000 Resources - Overview
The Eat at Joe's Kawai K5000 Message Board Digest
Additive Synthesis and Formant Filter Theory Overview


Overview on K5000 systhesys
 Monday, 05-Jan-98 14:03:12

      Message: writes:

      Just picked up a K5000R. I was knocked over by the sounds it made it the store.
      I became quickly depressed when I read the user Manual. The Manual
      seems like a decent reference. What I am looking for is an overview on the
      the beast works. This seems to be a very complex machine. I bought it for it's
      sonic potential. It's been fun twiddling presets but I really would like to
      understand how this works. By the level of some of the messages here it seems that
      there are some very sharp K5000 users here. Please point me in the right
      direction with respect to this mysterious machine. Thanks--- Ken 


Re: Overview on K5000 systhesys
Monday, 05-Jan-98 16:18:33 writes:

     The architecture itself isn't all that complicated once you figure it all out in
     the first place. The problem is that additive synthesis is so deeply rooted in
     audio theory, that you really can't tell what the manual is even talking about if
     you don't know some of the basics. I can't think of a good primer on sound theory,
     but here's a brief overview of the K5000:

     You have six sources (six "oscillators") per patch. Each of these can be either
     additive synthesis or PCM sounds. PCM sounds are just looped (or unlooped) samples,
     and much less powerful than the additive engine.

     Now for additive...

     Every sound you hear is comprised of several different frequencies. Most musical
     sounds you hear are comprised of a fundamental (the note you hear), and overtones
     (which are other, higher notes that are part of the sound). The reason why you
     hear only one pitch instead of all of the different tones making up the sound is
     that usually the fundamental tone is louder than the overtones, and also because
     your brain is designed to automatically locate the fundamental (usually the lowest
     tone in the series). Anyway, sounds are different from one another in large part
     due to different overtones in a sound.

     Sorry if you already know all of this, but this relates to the K5000 in that with
     the K5000 you have independent control over each of the overtones in a note.
     This makes the K5000 much more powerful than other synthesizers in some respects.

     That's what all of that ADD stuff is. You can set values (and volume envelopes)
     for each of the overtones. This represents a bottom up approach to sound
     creation (adding componants) - as opposed to traditional synthesis, which starts
     with all of the harmonics and then filters them out. Of course you can use the
     traditional filter and resonance on the K5000 to do the topdown approach too,
     so really you're squeezing something out in between when you make sounds
     on the K5000. This different style of synthesis explains why the K5000 can make
     sounds that you just don't hear on any other synth.

     The formant filter acts as powerful kind of EQ filter. You can set EQ settings
     for your sound, and then have those EQ settings evolve over time. It's kind of
     like a graphic EQ, but it has 127 bands instead of the usual 6 or so, and you
     can also create envelopes for each frequency.

     If you just want to get started quickly, you can just copy additive (and formant
     filter) settings from other patches. Some of them are saw waves (the standard
     traditional wave form). They will include every overtone and gradually decrease
     in volume toward the higher overtones.

     You can also play with the knobs while you are editing the patch and then save
     the patch. It will save changes you make with the patch (be
     careful though if you aren't trying to do this).

     In any case, this is a very mathematical instrument, which is why we wanted to
     get mathematical specifics regarding the values of all the settings from Kawai.

     Is that the info you wanted or is there something else?

     Maybe someone else can give their overview as well, or fill in some of my blanks.
     I see the message board digest turning into a FAQ in the near future....



Re: Overview on K5000 systhesys
Wednesday, 07-Jan-98 18:14:37 writes:

     I haven't found any books yet that are directly on the subject of additive
     synthesis. I've ordered some books on the basics of sound and music which may be
     helpful; I'll post anything good.

     There's some interesting stuff about the harmonic series in the encyclopedia,
     under "tuning." People debated for centuries what the right way to tune a piano
     would be. The problems arise from the fact that the harmonic series doesn't quite
     fit into even divisions of notes and scales. Anyway, there is some useful
     discussion of the harmonic series there.

     Also look under "Fourier". Additive systhesis is sometimes called Fourier systhesis
     because it is based in part on the mathematics he discovered. Also "Pythagoras",
     who discovered the harmonic series in ~500 B.C.

     Hmm, maybe I'll write a book . . . 


Formant n' Macro Q
Tuesday, 17-Feb-98 06:03:02 writes:

     Hello K5000 fanatics. I love the synth... manual is desperate though (sigz).

     I have two questions which I hope someone won't mind answering. They might be in
     the manual, but I certainly didn't get a clear answer from it.

     i) how do you save the current macro settings to your patch? Very useful so that
     you don't need to send all 16 knobs at the begining of every song via midi. I
     read that someone knew how to do this. If I juSt choose "write" it never saves
     the macro's.

     ii) anyone care to explain what the formant filter REALLY does? It just isn't
     ennough to twist the knob and get an interseting peep. Math won't scare me... the
     more technical the better. Didn't find any explanation in the manual for this
     one either...


     I'm very greateful for this site... it has been a few months that I've been
     looking for a useful place for the K5000. My warmest greetings to you all.

     Plush Studios.


Re: Formant n' Macro Q
Tuesday, 17-Feb-98 16:58:59 writes:


     2. You can look at the formant filter either as a customizable EQ that changes
     over time, or as a shapeable VCF type filter, but in the end these both mean
     pretty much the same thing. Subtractive synths (most synths that use the
     VCO/VCF/VCA architecture are subtractive) typically have some or all of the
     following filters: lowpass, highpass, bandpass, etc... Combined with resonance,
     which creates a peak at the cutoff point, this process creates a shape for the
     filter dependant on the settings. This, combined with the different waveforms
     you can select (which are defined by the differences in their harmonic series' -
     which means that once again the K5000 can achieve a much greater range by using
     additive synthesis, which lets you custom shape all of the harmonics)
     generates the timbre characteristic of a subtractive synthesis sound (not the
     K5000). With formant filter you can create a much larger number of different
     shapes to filter your tone by creating your own filter shape in the editor.
     Furthermore, not only can you apply an envelope to the filter bias (the filter
     frequency), as in subtractive synthesis, but you can also apply envelopes to all
     of the different frequency bands. It's really pretty amazing - and that's why the
     K5000 is so cool. With additive synthesis and the formant filter it should be
     able to do everything subtractive does, plus a whole lot more!

     For one given note, you could also create a patch that sounds like it's filtered
     without using any filters at all - subtractive or formant. You would do this by
     editing each of the harmonics so that they get louder and quieter at the right
     times (I think Jens' emulation of pulse width modulation does just that - it's
     really neato). This of course would be alot of work, which is why the envelopes
     for individual harmonics aren't used as much as they could be.

     What makes the formant filter process different from this harmonic shaping process
     is the fact that it generates it's frequency shape from specific frequency
     values (which are listed in a table in the manual - and can be modified and
     modulated with the "bias" control) as opposed to the additive process, which
     generates it's frequency shape from the harmonics of the note, which are relative
     to the fundamental tone (which in an ideal - and typical - situation is the note
     you press on the keyboard).

     What all of this means is that on the K5000S you have three different ways to
     create filtering effects (not including LFO's) - as opposed to the one envelope
     you usually get with subtractive synthesis. You could generate some incredibly
     complicated envelopes with this machine, because these can all be running
     (adding and subtracting form each other) simultaneously for an overall effect.
     I could be wrong, but it seems that there has yet to be written a patch that takes
     full advantage of *everything* the K5000 can do - it would just be such a large
     amount of work and also really hard to keep control of everything when it gets
     so complicated.

     Hope all of my little parenthesis and ramblings didn't confuse anyone, but I'm
     easily sidetracked.



Re: where can i hear a k5000, and a question about it's synthesis
 Thursday, 29-Oct-98 02:03:23 writes:

      I'm not really all that familiar with the SY-55, so I can't tell you what the
      differences are between it and the K5000. 

      Additive synthesis is the process where sine waves are added together. Each sine
      wave has it's own frequency, amplitude, and envelope. This is based on the idea
      that any sound can be broken down into individual sine wave components. If you
      want to know a little more, here is a place to go:



Formant Filter Overview
 Sunday, 31-Jan-99 04:03:59 writes:

      ---ugo wrote:
      > could you give me a general description of what the 
      > hell it really does? (and what each band really relates to?)
      > thanks,
      > ~*ChriS*~


      Thought this might be of interest to other people so while I take the
      time to write it up I might as well send it on to the list
      and post it on the message board as well.

      The formant filter is a filter for which you can customize the levels at
      each frequency. In traditional analog synthesis you can usually select
      between a couple kinds of filters - low pass filter, high pass filter,
      notch filter, and band pass filter being the most common. Furthermore,
      you have resonance, or Q, which creates a peak in frequency at the cutoff

      The filter will remove frequencies from the sound. By default it will
      remove fixed frequencies, regardless of the note being played (so when
      using a low-pass filter low notes will be less filtered than high notes).
      That's where KEYSCALE comes in. The KS to Cut parameter will make the
      filter frequencies follow the frequencies of the note being played (the amount
      to which it tracks the note is dependant on the amount of KS). Not sure
      if already know all of this stuff or not. You can hear all of this just
      fiddling with the DCF settings.

      Now a Low pass filter will have a frequency response something like this:

      Low Frequencies       \_   High Frequencies

      The high frequencies are getting cut out. Now apply resonance and it is
      shaped like this:

      Low Frequencies       \_   High Frequencies

      Notice the peak right before the frequencies begin to be filtered. This
      accounts for the nasal sound you hear when you turn up resonance (if you
      turn the resonance up and sweep the frequency cutoff low enough you will
      hear the peak accentuating the harmonics one by one - almost sounds like
      an arpeggio).  The amount of resonance will determine how tall the peak is.

      High pass filter looks like this:

      Low Frequencies _/       High Frequencies

      You are now cutting out the low frequencies and only letting the higher
      frequency components of the sound through.  Resonance creates the same
      peak behavior:

      Low Frequencies _/       High Frequencies

      You can select between the lowpass and highpass filter under DCF->MODE.
      The DCF on the K5K doesn't allow you to select notch or bandpass filters,
      but this is no big deal since you have the formant filter.

      With the formant filter you can create a filter that has any shape you
      want. You can recreate a lowpass, highpass, notch, bandpass filter and you
      can add a resonance peak if you want. Furthermore, the formant filter
      editing screen displays all of the formants (frequency values for the
      filter) graphically from left to right ranging from the lowest to highest
      frequencies of the filter. This means visually you can recreate the shapes
      that I have drawn above (If you make the formant filter follow one of the
      shapes above you should get an effect similar to that kind of filter). What
      you see in the formant filter editing window will basically translate directly
      into how the sound is filtered.

      Each of the values you can edit in the formant filter represents a half
      note - one key on the keyboard. There is a table listing the frequency and
      note values of each element of the formant filter in my K5000S book on page
      45. Unfortunately this table contains the only real data IN THE ENTIRE
      MANUAL that they have given us on how anything works inside the K5000.

      There is still another element, however, that effects the frequency range
      of the formant filter values. This is BIAS. BIAS is an offset applied to the
      entire formant filter range. If you raise the BIAS setting, the entire filter
      will move up in frequency.

      If you lower the BIAS, the entire filter will move down in frequency.
      BIAS is like the traditional Freq. Cutoff setting.

      If you create an envelope or apply the LFO to your formant filter, you
      are modulating the BIAS setting (i.e. move the filter higher up and lower
      down the frequency spectrum).

      Finally, you can use KEYSCALE again to track the formant filter BIAS to
      follow the frequency of the note you are playing. This has the same effect
      that applying KEYSCALE to cutoff value on an analog synth has.

      Anyways, this is the power of the formant filter: You can create a
      traditional style filter using it if you want, but you can also create any
      other filter shape that you want to create! It's very very cool and it is
      definitely worth spending some time getting to know it. Fiddle around with
      it and listen to how the sound changes when you change the parameters.