Talk:Wavetable synthesis

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???[edit]

I think declaring Wave's "jump from one wave from to another" system as inferior to modern samplers is somewhat disingenuous; for one thing, PPG's system had to work with the limitations of late 1970s/early 1980s technology, and memory was expensive then. With more sample memory and looser limits on sample length, you can build a single sample that has attack, loop and decay stages instead of jumping from one digitized single-cycle to another, and you can also use multiple DCOs to stack sounds together.

Sample based synthesis is really something else entirely. There are no samples in the sense a ROMpler uses the term in wavetable synthesis.-- 87.170.196.95 (talk) 19:45, 6 January 2008 (UTC)

Also, the page does a poor job of saying why the PPG and others like it are different from samplers; it also leaves out mention of non-PPG systems (except for a token mention of Roland's LA system), and the paragraph bashing sound cards toward the end is muddy and borderline POV. I can't sort all this out myself, but I hope someone who knows better can. -lee 21:28, 20 Jun 2005 (UTC)

Roland LA does use a non-looped sample for the attack and a looped sample for the sustain phase, which has no direct relation to wavetable synthesis. -- 87.170.196.95 (talk) 19:45, 6 January 2008 (UTC)


Wavetable synthesis is not PCM sample playback.[edit]

i'm happy for the article to be cleaned up, Lee, but not for the meaning to be changed to what is essentially PCM sample playback or Sample-based synthesis for which articles exist. one of the most annoying misappropriations of a technical term was what the commercial sampling keyboard industry (E-mu) and chip and soundcard manufacturers (Creative Labs and many others) did to jazz-up the term "sample playback" (which is not really any kind of "synthesis" at all) to the sexier "wavetable synthesis" when such a term already had a meaning and use that was not equivalent. probably some of the early references to Computer Music Journal regarding wavetable synthesis and group additive synthesis should be made in an article like this. but other than to dispel the notion that wavetable synthesis is PCM sample playback, i would not wish to see any confusion written in that would cause people to think these methods were the same. r b-j 02:00, 21 Jun 2005 (UTC)

Okay. I hadn't known about the Computer Music Journal articles, and coming from the world of PC soundcards myself, it's somewhat confusing to read that the term is somehow wrong or inaccurate. I do think it's being pedantic to strictly separate PCM playback and wavetable synthesis when the techniques are related so closely; indeed, even the Wave itself could play straight through a sample if told to, and the Waveterm add-on had a sampler in it. I'm not saying that the techniques are identical, by any means, but that one can emulate the other pretty easily given the right programming, and while E-mu's use of the term may have been inaccurate, I think it could also be stated that early samplers just didn't have the level of sophistication to emulate a Wave (whereas pretty much any synthesizer in 2005 can at least try). Also, I think a comparison with frequency modulation synthesis would be interesting, since (from what I've read) the original Wave's sounds and capabilities were akin to what the Yamaha DX7 could do. -lee 01:10, 27 Jun 2005 (UTC)
hi Lee. i s'pose you could say that a sampling keyboard could "emulate" any synthesis technique by either sampling the output of the other synthesizer or by, in an "off-line" process creating the same waveform in a memory buffer and, during the real-time playback, outputting that buffer when a Note On event is received. but i would hardly call that "synthesis", even though sampling keyboards can often be very cool instruments. i like to compare a sampler to the old Mellotron. a Mellotron is a sorta analog sampler.
"Wavetable Synthesis" as the term was originally used (these old CMJ articles from the late 70s or early 80s aren't online that i know of, but if you go to the AES site and look at the table of contents of the latest journal, you'll see an article by Andrew Horner which is about wavetable synthesis as used here) has at least one issue in common with PCM sample playback synthesis and that is about clocking through the samples at a different rate than one wavetable sample per output sample and interpolating between samples since that ratio is normally not an integer. but there really are fundamental differences. like a Numerically-controlled oscillator, there is only one cycle of the waveform stored in the wavetable, but it is normally not a single cycle of a sine wave. it's the complex waveform of some musical instrument (or some completely synthetic musical waveform). also there are more than one wavetable that are used to make the note evolve in time, from the attack through sustain and the release portions of the note.
coincidentally, here the term "sample" has a sorta dual meaning that can lead to confusion. when i use it, i mean the electrical engineering DSP definition: a single PCM data point. a single number representing a physical quanity (usually a voltage) at a particular instant of time. the other use of the word is that a "sample" of a note or a sound is the whole note or sound, usually a buffer or a block of memory or file space with many tens of thousands of PCM samples. the common, but misappropriated, usage of "wavetable synthesis" is the playback of that buffer at different rates, depending on which MIDI note is hit.
E-mu and Ensoniq sampling keyboards do the latter and Waldorf and the old Prophet VS ("vector synth") does the original kind of wavetable synthesis.
The ProphetVS does not do wavetable synthesis. It has four static NCO, and between two pairs of them a linear interpolation is done according to the X-Y-Vector parameter. -- 87.170.196.95 (talk) 19:46, 6 January 2008 (UTC)
As I indicated above, I am as certain that this statement is wrong as 87.170.196.95 appears as confident that it is correct. The Sequential Circuits ProphetVS does (or did) most certainly implement a form of wavetable synthesis. Perhaps with a lot fewer waveforms than the PPG/Waldorf synths, but again, that is a quantitative difference, not qualitative. 72.92.135.233 (talk) 04:54, 7 January 2008 (UTC)
You are apparently confused on what the term "wavetable" means (and the source of that confusion may be some ROMpler folks naming their sample-based synthesis "wavetable playback" for marketing reasons). The phase-to-amplitude mapping that certain NCO use for creation of the playback waveform is not a wavetable, at least not in the sense of wavetable synthesis. -- 87.170.224.38 (talk) 23:09, 22 January 2008 (UTC)
Actually, it is not 72.92.135.233 who is confused. It is 87.170.196.xx who is confused. You might wanna run my IP through Whois and see where it comes from. I design synthesizers (the signal processing) for a living. I wrote a seminal paper on Wavetable Synthesis. There is an old software product called "Prophet VS Wavewrangler", for which I did the DSP in it (if you can find the manual for it, my name is in the credits). The confusion of semantics is yours, 87.170.196.xx. We all (hopefully) know that "Wavetable Synthesis" is not the same as PCM sample playback that E-mu and all these other samplers do, even though for a period of time, the term had been hijacked by Creative Labs and other soundcard chip manufacturers because they liked the sound of "Wavetable Synthesis" better than "Sample Playback". But, in fact, the Prophet VS has 4 wavetables. That's what it has. The vector controls the mixing of those 4 wavetables (not in a linearly independent way, it could be defined as 3 wavetables mixed as a function of the x-y coordinates of the vector). The original Computer Music Synthesis articles refering to the term "Wavetable Synthesis" meant exactly a circular NCO playback mechanism where there was some means to change the definition of the periodic waveform in time (like as an envelope envolves). Perhaps, in some other case of semantic liberty, someone somewhere has defined in their synth's user manuals that the "wavetable" is a table of pointers to waveforms, but that is not and has never been the original definition of what a wavetable is. Sorry, 87, but the confusion of terms lies with you. Don't believe it, take it to the music-dsp mailing list. You can find out how to subscribe by Googling. 207.190.198.130 (talk) 05:50, 23 January 2008 (UTC)
You can hear it from John Bowen himself that he doesn't consider the ProphetVS a wavetable synth either: Solaris Oscillators (in case you are wondering, he created most if not all of the waves in the VS). 87.170.240.79 (talk) 21:10, 14 March 2009 (UTC)
my problem (and that of a few others that have worked on or with the "real" wavetable synthesis) is that while there are at least two other accurate and descriptive terms for sampling "synthesis" or sample playback or whatever you want to call it, there is only one good term for the wavetable synthesis that we're talking about here. no other term is as concise and accurate for it, but it's confusing when that "trademark" has been (mis)appropriated by soulless marketers of soundcards for something that is functionally different. r b-j 03:01, 27 Jun 2005 (UTC)
Okay, that makes sense. One of the things that was confusing me at first was the difference in terminology between PPG's/Waldorf's manuals and your paper; PPG uses just plain "waveform" for the waveform data (and to them, a "wavetable" is a list of how those waveforms play back over the duration of a note, what everyone else calls a patch), and your paper uses "wavetable" for the waveform data.
I also see your point about soundcards, and in my latest edit, attempted to offer an explanation; most of the soundcards in question were only ever meant to play back General MIDI files, and since GM only specifies a list of names (with no insight as to how to generate the sound), most people took the easy way out and used one long PCM sample per note (with maybe a keyboard split for higher/lower registers), even if the underlying hardware was capable of much more than what the manufacturer's Windows drivers let you do with it. On cards without a built-in MIDI controller, like the Live!, you can go directly to the DCOs and do pretty much whatever you want with them; having multiple waveforms per note is easy enough then (using the "wavestacking" method you describe), though it would most likely require custom programming to work. -lee 04:09, 27 Jun 2005 (UTC)

Confusing opener...[edit]

Being someone who has owned and worked extensively with analog, FM, wavetable, LA, samplers, ROMplers and vector synthesis machines, I feel it a disservice to lump or (perhaps) to even mention comparisons to Rolands LA synth engine with relation to a true WaveTable synth. They are really very different methods with their own strengths and uses.

Though it is true that one can somewhat mimic the other (as can be done with many methods of sound synthesis), the actual process of creating sounds is gone about quite differently altogether. A true wavetable synth can allow for both subtle and extreme effects that would be utterly impossible to create using Roland's LA system. Here are some additional problems below:

"Different wavetables can be used for the attack phase (at the beginning of the sound, as the volume increases) and release phase (at the end of the sound, as the volume decreases) of the sound. These are normally very difficult to synthesize with other synthesis techniques, but because these are stored as samples very realistic sounds can be produced with little processing power. The Roland Corporation's series of "Linear Additive" synthesizers such as the D-50 made use of a combination of digitally sampled attack phases."

This statement has numerous problems in addition to the unnecessary mention to Roland. What is difficult to synthesize? An attack phase? A release phase? Most wavetable synths sound anything but 'realistic' (accoustic would be a better term here) and it's rather clear from their general design that they were not intended to emulate such sounds - particularly when compared to the D-50 or a number of ROMplers on the market.

"Because single samples are somewhat limited for synthesis of new sounds, modern wavetable synthesizers can combine multiple samples or even change the sound with filters."

The very definition of a wavetable synth combines multiple (albeit very short) samples. Any synth featuring filters can alter it's sounds with them - this is not specific to a wavetable synth. More importantly, it is HOW a wavetable synth "combines" samples (animates would be more accurate) that gives them their unique qualities.

"Because of the low processing power required early synthesizers imitated filters and other expensive synthesis methods by rapidly playing successive wavetables in sequence."

Early synthsizers were analog (not digital or with CPUs) and therefore not wavetable synths at all. Early synths did not 'imitate' any process - they either did something, or they didn't. Most synths had analog filters, though some very early ones had none whatsoever. This statement could be helped by stating that this only pertains to digital-waveform based synthesizers - some of which may have lacked analog filters due to the expense of adding them into the sound chain. But this was certainly not limited to wavetable machines - and to the best of my knowledge, all the wavetable synths I'm aware of until very recently actually HAD analog filters. What they did lack was variable pulse-width waveforms, which could be easily emulated using a wavetable.

There are some other minor problems as well, but I feel I've made my point. There is a general lack of clarity in the opening statements. I could re-write much of this, but feel it would be foolhardy to do so without first pointing out some obvious problems and getting feedback.

Antfactor 22:38, 15 September 2005 (UTC)

i think nearly everything you've written here is right on. i am much less familiar with all of the market so i have not commented on products even though some i know do true wavetable synthesis such as the Waldorf and predecessors and the old Prophet VS. i suspect there are sampling keyboards listes as wavetable synthesizers and that is something i would like the article to get away from. r b-j 00:01, 16 September 2005 (UTC)
Actually, that "low processing power" bit was something I was working on a while back...what I meant to say was that PPG's own systems had to do it that way back then because the technology available back then didn't allow anything more complex (in particular, Palm wanted to use wavetables to replace filters, but couldn't get crossfading to work so used an analog filter instead). I don't remember if I wrote it, or if someone before me did. As for the other problems, I can go ahead and clean those up; the D-50, from reading about it, looks more like my Casio CTK-611 at home (which definitely is a ROMpler) than a wavetable synth. -lee 19:12, 9 January 2006 (UTC)
It was actually Wolfgang Dueren (sales manager and later a founder of Waldorf GmbH) who insisted on the inclusion of analog filters. The early PPG Wavecomputers didn't have filters. -- 87.170.196.95 (talk) 19:45, 6 January 2008 (UTC)
Lee, we gotta work on this. For some reason, even though this is on my watchlist, i missed these last changes you made which have the effect of moving the definition of wavetable synthesis back to the PCM sample playback definition which was usurped by chip manufacturers (like Creative Labs) and E-mu as a fancy term for sampling and it is not the same as what the original use of the term was, which is more along the lines of Waldorf or Palm (i think) and the old Prophet VS. We gotta work this out because I really do not want to consign the term "wavetable synthesis" to that term was usurped from its original meaning to something else not quite the same. r b-j 01:40, 3 February 2006 (UTC)
Hmmm. I was under the impression that the rewrite I did to the '"wavetable" sound cards' section made the difference more clear. Maybe it would be better if the sound cards were not mentioned at all? -lee 02:22, 5 February 2006 (UTC)
Also, what was wrong with the beginning? Most of the rewrite I did there was directly from PPG's own documentation for the Wave 2.3, and someone else stated that the D-50 doesn't really count here (it's a halfway approach I've seen Sound On Sound calling 'S&S'), so I made sure to edit that out. -lee 02:25, 5 February 2006 (UTC)
Ah...I went back and read all the documentation I could find for the Wave 2.2/2.3 (and found Hermann Seib's excellent WaveSimD on the Waveterm C site), and it seems that I've been missing the point...it's not the samples, it's how the CPU can move through the table and fill in waves that don't actually exist in ROM (that Palm could do that on a 6809 is pretty amazing, but then again the Fairlight designers used the 6809 as well and it's quite a bit more involved). I see what you meant by the additive synthesis bits, as well; most of the tables move from a simple wave to something far more complex, almost like pulling out the drawbars on a Hammond. There's even a few that are just function generators, completely done in software. This thing is absolutely mad, and it's no wonder I couldn't understand it at first. -lee 04:40, 5 February 2006 (UTC)
do you mean by "function generator" an ADSR thing or do you mean a (static) waveform producing thing? r b-j 04:45, 5 February 2006 (UTC)
Static waveform producing thing (I'm used to the old-style function generators used in analog electronics, which aren't all that different from analog synthesizers). The PPG docs call that particular wavetable "phased saw waves", and the table I was reading said that particular list of waves was calculated by the CPU instead of being stored in ROM somewhere. -lee 07:45, 5 February 2006 (UTC)

Also, what was wrong with the beginning? Most of the rewrite I did there was directly from PPG's own documentation for the Wave 2.3, and someone else stated that the D-50 doesn't really count here (it's a halfway approach I've seen Sound On Sound calling 'S&S'), so I made sure to edit that out. -lee 02:25, 5 February 2006 (UTC)

okay, let's work on this a little. here is the last version before the last revert - that is your intro with some other small changes made by third parties:
Wavetable synthesis is an algorithm used in early digital musical instruments (synthesizers) to produce sounds based on either a natural sound (such as a piano or a guitar), or pre-determined waveforms like the ones generated by analog synthesizers. The sound of an existing instrument or function (a single note) is recorded and parsed into a set of samples having one period or cycle each. These samples or waves are then combined together using lists called wavetables. Upon playback, the wavetable controls which waves to play and where to crossfade or loop. Special effects can be achieved by selecting a wave at random, sweeping through all of the waves in a table in sequence, changing waves on a tempo-tick from a sequencer, or using the modulation wheel, LFO or envelope generators to jump through the wavetable. This creates effects that are very "digital"-sounding, similar to FM synthesizers like the Yamaha DX7.
A patch can consist of a single wave (producing the same effect as an analog synthesizer), or an entire wavetable composed of many different waves. Early wavetable synthesizers had all of their wave samples referenced in order in their wavetables and could only sweep or seek inside a given table, while later ones (such as the Waldorf Wave) keep the wave samples and wavetables separate, making it possible to create new tables from existing sounds.
i might make these initial changes in the first:
Wavetable synthesis is an algorithm used in early digital musical instruments (synthesizers) to produce sounds based on either a natural sound (pre-existing instruments such as a piano or a guitar), or pre-determined waveforms like the ones generated by analog synthesizers. The sound of an existing instrument or waveform (a single note) is recorded and parsed into a set of wavetables having one period or cycle of the waveform each. The waves generated from wavetables are then combined together by some defined means, possibly mixed or possibly sequentially with cross-fading. Upon playback, the synthesizer controls which wavetables to play and how and where to mix with or crossfade to other wavetables. Special effects can be achieved by selecting a wave at random, sweeping through all of the waves in a table in sequence, changing waves on a tempo-tick from a sequencer, or using the modulation wheel, LFO or envelope generators to jump through the list of wavetables. This creates effects that are very "digital"-sounding, similar to FM synthesizers like the Yamaha DX7.
you see, the wavetable is the memory buffer that contains one cycle or period or "wave". e.g. the Prophet VS had 4 wavetables each could be arbitrarily defined but they all had 128 samples. the list or collection of these wavetables another term (i believe Korg might have called that a "wave-sequence", but i am not sure that the WaveStations were wavetable synthesizers in this sense or if they were more like samplers. it looks to me that this usage from PPG is calling a "wave" what us technogeeks call a "wavetable" and the list or string of waves, they are calling a wavetable (and i think the term i would use is a wave sequence or wavetable list or similar). r b-j 04:45, 5 February 2006 (UTC)
From what I can tell, the Korgs were the follow-ons to the Prophet-VS, and one page I found refers to the list of waveforms as "wave sequences" (and says the Wavestation could string together up to 255 waves and chain sequences together for even more). And yeah, PPG did indeed call the sequence lists "wavetables"; that's one of the things that was confusing me when I first found this page. It'd be good to say something about the usage of the term in the article (and I did write something like that in the edit I was working on before I re-read this page). -lee 07:15, 5 February 2006 (UTC)


Wavetable vs Vector Synthesis[edit]

Does anyone know the difference? I'm not too clear on vector synthesis, and there is no entry..although there should be! I'm inclined to think there's not much difference...would that be incorrect?

Yes it would be incorrect, although you can conceivably combine the two. Vector synthesis uses n-dimensional parameters to navigate to different locations in the parameter space. As implemented in the ProphetVS the boundary of that parameter space is defined by four single-cycle waves and the navigation is done by linear interpolation between these four waveforms. Other than the fact that the four waveforms are single-cycle, there is really no relation to wavetable synthesis. -- 87.170.196.95 (talk) 19:45, 6 January 2008 (UTC)
That's the critical relationship. It's wavetable synthesis if single cycle waveforms are generated by use of an NCO and there is some mechanism to gracefully change from one waveform to another. Whether it is 4 waveforms or 64, the difference is quantitative, not qualitative. The Prophet VS most certainly does wavetable synthesis. If the two coordinates of the vector went into some other kind of synthesis engine, say they were FM synthesis parameters, then it wouldn't be wavetable synthesis. But the VS is using these two parameters to control the mix of 4 wavetables. 72.92.135.233 (talk) 04:54, 7 January 2008 (UTC)
Nope. There is no wavetable (let alone four), just four waves and two linear interpolators.
What do those "waves" live in? Could it be a ... lookup table? Could such a "lookup table" that has a "waveform" stored in it maybe be called a ... wavetable?
There is no wavetable oscillator (in the PPG sense) either, because the VS lacks the ability to change the waveform it is playing back on-the-fly.
Totally untrue. Moving the joystick on a VS doesn't change the waveform??? I guess it doesn't if all four wavetables (or "waveforms" as you would call them) are identical. Then moving the joystick around would not change the waveform. But if you have four radically different waveforms stored in those four wavetables, then it is certainly true that moving the joystick around changes the waveform on-the-fly and has been used expressively by people who play and love the VS.
The waveform is not changed on any of the four oscillators. The mix between them changes and so does the waveform after the mixer. -- 87.170.194.124 (talk) 18:36, 25 January 2008 (UTC)
You really need to get your terminology correct if this is meant to go anywhere: in wavetable synthesis there are waves and tables thereof. The entries in a wavetable are waves and it's not wavetable synthesis unless you can move the wave index through the table in any manner you see fit during playback.
It's another use of the term that is not the original use (in that way it is similar to how PCM sample playback has adopted an existing term and changed the meaning of it). The entries in a wavetable are numbers representing the instantaneous-time value of the waveform. What you call "waves" are, in actual implementation, wavetables. What you refer to as a wavetable, might be called a "wavestack" by Korg, or a "wave sequence" by nearly everyone else. A single wavetable defines, point-by-point, a single waveform.
You tell me which definition came first (I wasn't around to witness the development of the terminology in the 70s), but the fact remains that the terminology as used by W.Palm (PPG) and the one that you are using is incompatible as the same words are used for different concepts. That is why I said "wavetable oscillator in the PPG sense". -- 87.170.194.124 (talk) 18:36, 25 January 2008 (UTC)
While the particular form of vector synthesis employed by the VS can be emulated with some (not the PPG) forms of wavetable synthesis, the implementation and the concept is actually different. The VS has four oscillators playing four waves and two cross-faders interpolating between two pairs of oscillators. The oscillators happen to be implemented as NCO playing single cycle waves, but you can replace them with just about anything else that produces a waveform without changing the concept. A wavetable synthesizer on the other hand would employ just a single oscillator for the same result (by mapping X and Y to a single parameter) or — to facilitate easier emulation or greater resolution — two oscillators; but never four.
What is it that is in those oscillators? If those oscillators were constructed (even by use of DSP code) by some algorithm that creates the waveform solely by math, and not by table lookup, then it isn't wavetable synthesis. But if there is little math (other than the math needed for interpolation between samples in the lookup table) to create the waveform, that is if the waveform is simply defined by a circular table of sequential numbers, we're already more than halfway there to "wavetable synthesis". Whether it is mixing or cross-fading or stepping through a bunch of different wavetables is a difference of implementation. But it's all wavetable synthesis.
Now if the term wavetable is already used up for the phase-to-amplitude mapping you can't of course use it again for something else entirely. But that is somehow necessary when you want to talk about the PPG and it's descendents. -- 87.170.194.124 (talk) 18:36, 25 January 2008 (UTC)
I know this is confusing, but please keep concept and implementation separate and if talking about both some seemingly small details really do matter. -- 87.170.240.82 (talk) 22:33, 22 January 2008 (UTC)
Small details are important. Initial concepts and terminology are even more important. It is you, 87, who got the terminology wrong, not 72. I can say that I, at least, am not the least bit confused. With 72.92.135.233, I just disagree with you on what the terminology means. Google "Andrew Horner" (he is not me) if you want to see another example in print of what authors have (for a very long time) defined as "wavetable synthesis". 207.190.198.130 (talk) 05:50, 23 January 2008 (UTC)
I know your article very well, and I'm certainly not going to argue with you about it. I merely point out (again) that a wavetable in W. Palm's terminology is something different than in yours and that in his definition it isn't strictly necessary to use what you call "wavetables" for what he calls "waves" (that his "waves" are your "wavetables" is an implementation detail). What you call "wavestack" or perhaps "wave sequence" however is (at least if I understand it correctly) dependent on having multiple "wavetables" (your definition) in the first place. And maybe even while none of us is confused, the article is still confusing, IMHO: it talks about "wavetable synthesis" and then jumps to "Palm's wavetable systems" without even the slightest mention that the underlying terminology is completely different. I'm happy to be called wrong and confused if the readers of the article will at least be made aware of that clash of definitions. -- 87.170.194.124 (talk) 18:36, 25 January 2008 (UTC)


Pronunciation[edit]

Is it pronounced as "wavetable" (as in "edible") or "wave table"? - 99.247.136.86 07:35, 12 November 2007 (UTC)

The latter: it is a table consisting of waves. -- 87.170.196.95 (talk) 19:45, 6 January 2008 (UTC)


Definition[edit]

Wavetable Synthesis as a concept is aiming to simplify the simultaneous control problem you have when trying to do fully additive synthesis and also address the gross inefficiency of computing many partials in realtime even though the waveform changes only slowly. The solution is simply to define the control trajectory and sample the resulting waveform at (equidistant) spaces on that trajectory, which leaves only a single control parameter (the wavetable index) and a very efficient implementation for the playback mechanism. Wavetable synthesis as defined by PPG pre-computed to single-cycle (odd symmetrical) waves and added the interpolation between waves in a table as a mechanism to further save the computation and storage of unnecessary data. The wavetable is completed and the waves expanded to full-cycle in RAM on the PPG, so these are really details of the implementation.

So, the PPG definition of wavetable synthesis is: a table of 64 single-cycle waves addressed by a single parameter (the wavetable index). Scanning the wavetable with an appropriate index sequence produces the desired timbral changes over time. The index sequence does not need to be continous nor monotonic (in contrast to sampling, where the index would be strictly linearly ascending). Later incarnations of the technique have provided smooth interpolation between wavetable entries (i.e. you can use fractional index values) and reduced artifacts (aliasing, quantization and scanning noise) inherent to the implementation details of the original implementation. -- 87.170.196.95 (talk) 19:45, 6 January 2008 (UTC)


Etymology[edit]

Pertinent to the discussion on the original terminology above, here are some dates on the various uses of the term "wavetable". Please add any references that you have access to (mine are limited to some owners manuals I have on hand and several online libraries, which do not always cover the time frame in question). -- 87.170.246.81 (talk) 14:28, 26 January 2008 (UTC)

The term "wavetable" in the PPG sense appears latest 1982 (ref. Wave 2.2. Owners Manual) and probably as early as 1978 (with the Wavecomputer 360). The original german documentation uses the word "Wellensatz", which could also be translated into "wave set" instead of (as has been done) "wavetable" (which would correspond to the german "Wellentabelle", which I've never seen used anywhere except when directly "Babelfish-style" translated from english). -- 87.170.246.81 (talk) 14:28, 26 January 2008 (UTC)

The term "wavetable synthesis" in the meaning NCO with (circular readout) waveform memory can be traced back online to about 1992. The earliest citation that may or may not be using the term in that sense I've found so far is G. de Poli's "A Tutorial on Digital Sound Synthesis", Computer Music Journal, Winter 1983 (unfortunately I don't have access to the full article, so I don't know if the article is indeed replacing the term "fixed waveform synthesis" with "wavetable synthesis"; there's also a citation to Mathews 1969 that I'd like to know more about). However, if the waveform memory contains a sine wave, then it is not commonly called a "wavetable" (if it were, the original FM synthesis as conceived by Chowning would be based on wavetable synthesis and I have yet to find anyone who says that; although in the AFM implementation — starting with SY-77 — the sine table could be replaced with 16 other waveforms). Remark: The moniker "wavetable" for the content of a single waveform memory would translate into "waveform" in the PPG literature and later simply "wave" (Waldorf). -- 87.170.246.81 (talk) 14:28, 26 January 2008 (UTC)

The Prophet VS and the Wavestation came several years after the PPG, so they can't establish any claim on introducing original terminology w.r.t. "wavetable". The term "wave sequencing" however may have been originally introduced with the Wavestation. -- 87.170.246.81 (talk) 14:28, 26 January 2008 (UTC)

The term "waveform sequencing" is already used in the 1979 paper of Andresen from PPG. 87.170.253.79 (talk) 16:23, 14 February 2010 (UTC)

The term "wavetable synthesis" in conjunction with PCM playback (and in contrast to FM synthesis), especially on PC sound cards is traceable into the early 1990s. (ref. A single-chip multimedia audio system with digital sample rate conversion and FM sound synthesis) and perhaps coincides with the sale of E-Mu to Creative Labs (1993). The WAVE Blaster add-on card (which is based on E-Mu technology) was introduced a year earlier IIRC. -- 87.170.246.81 (talk) 14:28, 26 January 2008 (UTC)

We agree about the use of the term "wavetable synthesis" in reference to PCM sample playback. I'm not sure exactly who hijacked the term first, but I suspect it was Creative. But before Creative bought E-mu, Dana Massie wrote that one chapter in Applications of Digital Signal Processing to Audio and Acoustics (ca. 1998) titled Wavetable Sampling Synthesis from something that he presented to the IEEE Mohonk in the eariler 90s. (By including both words, "wavetable" and "sampling" he was able to keep in sorta ambiguous so not to be completely pinned down, but I would have preferred it if he kept the term "wavetable" out of it.)
Now my first impression of the term was with the Fairlight CMI [1]. Their waveform drawing was just defining the values in multiple wavetables that were played in sequence. That article directly links the evolution of the synth technique from PPG through the VS and then onto the Korg Wavestation:
The ways in which waveforms are switched and combined in the PPG devices were extended in the 1986 Prophet VS from California-based Sequential Circuits, a device which enabled envelopes to dynamically crossfade four evolving audio sources via what Sequential termed "Vector Synthesis". After Sequential ceased operation, the VS was taken over by Korg, where it evolved into the popular Wavestation in 1990.
But then they go on to confuse it with PCM sample playback with this:
Wavetable synthesizers directly targeted acoustic instruments in 1983 with the K250 by Massachusetts-based Kurzweil Music Systems.
I am still trying to find, in CMJ, the first use of the term, but I don't have these scanned and OCRed. I'm just looking through them. As best as I can tell, there is no use of the term wavetable anything in the 1983 De Poli article, but he does describe "Fixed-Waveform Synthesis" from table lookup. But no specific mention of the word "wavetable".
The recent book by Martin Russ Sound Synthesis and Sampling clearly links the term to the CMI, PPG, the VS, and Waldorf, but then includes the Ensoniq ESQ-1 and Fismo which seems to confuse the issue again. The ESQ-1 was a sample playback synth, [It appears that the Ensoniq ESQ-1 is not a sample playback synth, it as "oscillators", so I retract that statement. Nearly everything else from Ensoniq were sample playback.] and I don't know what the Fizmo did. He also uses the term "Wave-cycle" synthesis, but from the figures and description, I cannot tell how Russ differentiates between the two.
Now, just to be clear what it is we see congruently and what we don't: "Wavetable synthesis" involves the reconstruction of a waveform stored in memory, right? That one sentence description is so broad that it can include simple PCM sample playback that the soundcards and samplers like E-mu and Ensoniq used to do, but we agree that that was a sorta bastardization of the term, right? The "wavetable" that you mean is a table of pointers to tables of single-cycle waveforms all stored in memory (it's a table of waves) and the waveform can vary rapidly as the index to these pointers varies, right? Do I represent your position correctly? While the "wavetable" that I mean is the table that holds the samples of the single-cycle waveform itself (a particularly boring example would be the static waveform that never changes, but that could be called "wavetable synthesis" although I would prefer to call it an NCO or DCO with perhaps something other than a sine wave in the wavetable). In any decent instrument, the waveform should be changable somehow, either clunkily by just switching between "wavetables" or smoothing by interpolating or cross-fading between the same.
But I just want to be clear, you say the "wavetable" is the table that contains pointers to the sequence of single-cycle waveforms, right? (Or do they even have to be single-cycle, from your POV?) 207.190.198.130 (talk) 03:52, 28 January 2008 (UTC)
Here's a link to what Julius Smith says is wavetable synthesis: Spectral Audio Signal Processing particularly [2]. 207.190.198.130 (talk) 03:05, 29 January 2008 (UTC)
[I'm trying to keep my comments together.] Thank you for looking up the literature that is inaccessible to me. I'm well aware that the current use of "wavetable" or "wavetable oscillator" in the (music synthesis) literature is as you state and I don't contend that. I can see this usage has been picking up since the mid 1990s, which somewhat coincides with the "hijacking" of the term by the soundcard guys (this may be incidental, or not). I still find this somewhat disingenuous as at that time there already had been a perfectly good term for this type of signal generator: arbitrary waveform generator (AWG), as opposed to the more specialized direct digital synthesis (DDS) when talking about sine wave generation. -- 87.170.251.205 (talk) 08:10, 29 January 2008 (UTC)
On to my POV with regards to wavetable synthesis: as implemented by PPG there is both a lookup table for individual waveforms and a table index to switch between those waveforms in realtime. This particular implementation was IMHO very much driven by the hardware constraints, while the greater idea behind it is much less dependent on these details. While the use of single-cycle waveforms and the particular implementation of the readout gives much of the signature sound to the PPG, the concept itself does not depend on it. In a more general sense each entry of a "wavetable" describes the spectral properties or timbre of a wave synthesized at this point (it is largely irrelevant whether this is done in the time or frequency domain or even algorithmically) and conveys some means to get from one entry to the other, that is to produce changes in timbre over time. Importantly, there is no conceptual implication that the table index has to move sequentially through the table or that the points in the table are "equidistant" (in contrast to many implementations that do). Also, the amplitude envelope of the synthesized signal is not part of the wavetable at all (again in contrast to an implementation where the table indes is sequential and at the same time is used to index another AWG lookup to produce amplitude envelope information). [Palm quickly realized that despite marketing claims to the contrary this was not a good way to produce "nature-like sounds", and used the same hardware for what he called "Transient Sounds" - which are nothing but (relatively short) PCM samples with optional looping of the end.] FWIW, Waldorf used the term "dynamic spectral wavetable synthesis" in their early literature — depending on what the scope of the article is intended to be this may be an opportunity to resolve the ambiguity by splitting that off into a separate one. My contention with defining "wavetable synthesis" just as a fancy term for synthesizers using an AWG in their implementation is that so many synths would fall under that definition as to render it useless, IMHO. The other entries in Category:Sound_synthesis_types [sorry, can't get the link to work] are a mixture of concepts and actual synthesizers implementing it, so it's not clear to me which was intended or if indeed anyone planned these separate articles to be somewhat coherent. They probably should be, though — it's an encyclopedia, after all, and in this case I'd lean to bringing the concepts forward and keep the actual implementation with articles about synthesizers. -- 87.170.251.205 (talk) 08:10, 29 January 2008 (UTC)
That's the problem the article has had all along; it's never really been clear where the concept ends and the PPG Wave's implementation details begin, making it so that synthesizers that are "sort of" like the PPG get thrown in without really understanding what's going on. If we want to talk classifications, then the PPG would fit best in the first wave of digital synths, the real-time additive class (which also includes things like the original Fairlight and Synclavier before they thought to add sampling, the DK Synergy and the Kawai K5). It wouldn't be a perfect fit, but it might be worthwhile to merge some of this article into a section (or perhaps a new article) covering this class of machines, sort of like what's been done with video game consoles (where at least one second-generation console was a 16-bit machine in an era where 8-bit machines ruled).
As for the amplitude thing, I was working from the standpoint of something like a Hammond organ, where you can pull on the drawbars to change the harmonics of the wave without affecting the overall volume too much (assuming you set a sane baseline). You wouldn't be able to do something like 01000 0000 to 88888 8888 on a PPG without using the ADSR, though. -lee (talk) 19:57, 9 April 2008 (UTC)


The Ensoniq interpretation of the theme was called "Transwaves", culminating in the FIZMO. From what I understand of the technique Transwaves basically are multi-looped samples arranged in a way so that they can be played in a linear fashion. I've never had one myself, but the result sounds indeed "wavetable like", likely a result of the short loops (not necessarily single-cycle from my reading of it) which produce the characteristic "perfect" harmonics. -- 87.170.251.205 (talk) 08:10, 29 January 2008 (UTC)

November 2009 Edit[edit]

Nov 2009: I radicaly changed this article: It was very confused between PCM sample playback and wavetable synthesis. I own 2 wavetable synths - a VFX and Access Virus Ti plus PD, FM & VA and have owned LA synths. I hope this article now represents a true deffinition of wavetable synthesis. For the poster above: The Profet VS had 2 user definable wavetables, which were in effect wave sequences. However, as they could be played in any direction they are true wavetables. There is a fine line between wave sequences and wavetables. Maybe the Korg Wavestation could be included here. Note Vector Synthesis and wave sequencing are 2 very different synthesis methods. —Preceding unsigned comment added by 91.180.189.8 (talk) 23:51, 30 November 2009 (UTC)

The Prophet VS had nothing that resembles a wave sequence, this has been discussed before. If you must think of the Prophet VS as a wavetable synthesizer (which it's creators do not), then it has a very fringe implementation of two two-entry wavetables with linear interpolation. 87.170.253.79 (talk) 16:23, 14 February 2010 (UTC)

February 2010 rewrite[edit]

Since nobody seems to have picked up on the cleanup requests and the discussion has come to a halt, I've done a complete re-write that hopefully includes most of the discussion as documented on this page. There are certainly things to add and change, but I hope that at least the definition of the terms is more agreeable. 87.170.253.79 (talk) 16:23, 14 February 2010 (UTC)

Ugh! This article is as clear as mud.[edit]

I'd re-write it myself, except I turned to this page because I did not know what "wavetable synthesis" actually means. After reading the article, I still don't know. But I can make some guesses.

A wavetable synthesizer is like a digital version of a subtractive analog synthesizer. It contains oscillators, envelope generators, filters, and various kinds of modulators, all implemented in the digital domain. Unlike an analog oscillator which usually can generate only a few different wave forms (e.g., square, triangle, sawtooth), a wavetable oscillator can reproduce any continuous waveform, using data stored in a "wave table." A wave table is not like a "sample" in a sampling keyboard. A "sample" is a digital recording of an entire musical note; its attack, its decay, maybe a looped sustain, and its release. A wave table, on the other hand, contains just one cycle of a continuous, periodic waveform. The time varying attributes of a note in a wave-table patch are determined by the filtering, modulation, etc. as driven by envelope generators---just like in an analog synth.

That's only a rough cut, and that's only my guess, but it sounds like that is the essence of what this article tries to say. Am I right? —Preceding unsigned comment added by 71.199.121.113 (talk) 18:41, 22 March 2010 (UTC)

There are a few falsehoods in your understanding. First, what is true: a wavetable oscillator can reproduce any [bandlimited] continuous waveform, using data stored in a "wave table."
The fact is a wavetable *does* have a lot to do with a "sample" in a sampling instrument, but it's not quite the same. Some (but certainly not all) samples are looped with a single cycle loop. That loop is directly comparable to a single wavetable.
A wavetable synthesizer has several wavetables representing the waveform of the note at different times; perhaps a few just after the attack (when the note is transitioning rapidly) and a few as the note decays. The time varying attributes of a note from pure wavetable synthesis are accomplished by cross-fading from one wavetable to the next in the evolution of the note. That doesn't mean that effects cannot be applied afterward, but those are post effects, not specifically what we mean by wavetable synthesis.
I agree that the article got really messed up since previous versions that are a year old or more. That's what happens with Wikipedia. There is nothing that guarantees that articles improve or even remain stable in quality. Sometimes article quality declines. 70.109.180.126 (talk) 20:04, 22 March 2010 (UTC)
If a sample loop is equivalent to a single wavetable, then therefore sample playback is a form of wavetable synthesis (single-table). Sampling-based synthesizers can also layer multiple sounds together in various ways. If I can overlay three different sounds on the keyboard, with different envelopes for amplitude or other filtering, then don't I in fact have wavetable synthesis with three tables? Thus the article lies: makers of sample-based synths have a legitimate claim to "wavetable synthesis". 192.139.122.42 (talk) 23:53, 25 March 2011 (UTC)

WTF is wavetable synthesis?[edit]

If we are reading pre-computed waveforms from a table and combining them together, how is that not just a mashed-up sample playback? How does wavetable synthesis produce different pitches? Wouldn't it pitch-shift the wavetable data, exactly like sample playback?

This article does a good job of explaining what Wavetable synthesis is not, and what it's confused with.

The problem is, it lacks a description of what Wavetable synthesis is.

Some block diagrams, pseudo-code, anything, would help.

What does the data look like, and what process is applied to it when, say, I hit the middle C key on the synth keyboard?

192.139.122.42 (talk) 23:49, 25 March 2011 (UTC)