For a while now I wanted to do a quick comparison of Blade and Razor, two additive synthesizers recently developed by Rod Pappen and Native Instruments. I don't believe the timing of their release so close together is mere coincidence but rather they both reflect a development in additive synthesis that is worth mentioning.
The Holy Grail if Synthesis
Additive synthesis might have seemed to be a kind of holy grail of synthesis at least for a time. I think it has matured and that expectations of what it can and cannot do are more realistic. It's promise is that it can recreate any timbre changing over time. However, I believe one need only look to the history of additive synths to see how difficult a task it is to make additive synthesis an effective musical tool more than a scientific and mathematical curiosity.
My first experience with additive synthesis was with Absynth although it is a stretch to say Absynth has additive synthesis. Absynth has a parallel waveform/partials display. In this sense a pipe organ or a Hammond B3 or many other types of organs are additive synthesizers albeit with a very limited number of partials.
The next additive synthesizer I bought was VirSyn's Cube and latter Poseidon. Both of these synthesizers allow a sample to be re-synthesized. This is a process by which a sample can be broken into a series of partials each with their own amplitude and pitch envelopes.
The reason for doing this is not to reproduce the sample. Samplers do a better job of this anyway but rather to be able to morph sounds and speed up, slow down and freeze time in ways samplers can't.
The Next Generation
The next generation of additive synths that came out about the same time were Vir Syn's Cube and Camel Audio's Chameleon which was really the father of Alchemy. In all of these synths additive models can be morphed one to another and time can be sped up, slowed down or even frozen without the need for looping. Of course, such methods are not without artifacts.
Cube had a feature that allowed the user to draw spectrums and spectral envelopes. In theory, this all sounds great but how does one distinguish between on spectrum and another or their envelopes and make a mental connection with the sound. This is really what I saw early in the game as the problem with additive synths. That and the discovery I made that the brain really makes little distinction in timbre in terms of higher order partials which are mostly perceived as buzzy unless (and this is big), there are a series of peaks that provide a kind of shape if form to the partial much like formants which speaking of the synthesis if the human voice. If anyone reading this has purchased or looked at demos of Blade or Razor, these peaks will be familiar.
This is really why filters are so important. How one shapes the lower order partials is really what gives strong character to a sound but also how that shape changes over time. Early analogue synths all are based on broad spectrum waveforms. That is, waveforms with a lot of higher order partials. One might liken it to a sculpture with a block of marble. Filters then act as the chisel to chip away at the higher order partials that can be harsh and not very musical. Envelopes help to shape over time emulating the characteristics of real instruments.
The Shape of Things to Come
So with that said, it's my guess that both Rob Pappen and Native Instruments wanted to correct for these problems and came up with tools that reduced the overall "dynamic" shape of the partials to a few parameters. In Blade these are called Harmolators. The idea is that working with parameters that define an overall shape if a waveform allows the user to get a handle on what effects the overall sound without having to think about individual partials. What is missing is any form of re-synthesis which is interesting given that this was the central focus of additive synthesizers before this.
Overview and Central Focus
I believe it's no mistake when you look at the main screens of Blade and Razor that each have a very different focus. Blade's screen features an XY style pad with multiple Harmolators on the side which change as the cursor moves over the XY space. The movement of the cursor can be recorded and a number of preset patterns are also available. Blade also offers an LFO, envelope and two other modulation sources which all control Harmolators. It is the Harmolators that are the central focus if Blade.
Razor focuses more directly on the shape of the partials both in 2D and 3D although the 3D display is a bit more of a CPU hog. It offers two oscillators, Two additive filters, dissonance effects which I believe are unique to Razor and very interesting. Also stereo and dynamic effects, 2 LFOs, 3 envelopes, a side chain and a few controls related to controlling the real potential of Razor to shred speakers. Modulation takes the form of controls for each component which appear as a small circle below each knob. The modulation options are extensive.
The Partial Paradox
Any additive synth is going to have partials and lots of them. The problem with an additive synth that is not re-synthesizing is that one has to start with very broad spectrum and dare I say somewhat buzzy waveforms. Of course noise is all the rave today (pun intended) with the Hoover sound actually earning it's own Wiki page. So in many ways. the broad spectrum buzz saw of dancing partials is ear candy to many.
The real trick is to find interesting ways to shape these partials. Without going into details, Blade starts with some interesting starting shapes and patterns (such as primes only) and then makes broad morphs to the overall shape such as ripples (no doubt intended to be like formants), number of partials, left or right skew even and odd partial distribution reminiscent of tube and tape saturation and many other acoustic effects.
Razor's approach to oscillators is radically different. First, Razor does not have a large collection of starting shapes. Rather, it offers a collection of broad form waveforms that mimic classic analogue sounds with some really unique and creative waveforms that provide what I believe is a broader sonic pallet than Blade despite the fact that blade offers a lot more choices of waveform.
Here is the big difference between Blade and Razor. Blade has a rather substantial library of waveforms which are shaped by Harmolators. Razor has a limited number of oscillators which are very analogue in nature but very flexible. Unlike Blade where each oscillator is shaped by the same Harmolators, Razor's all have parameters specific to an oscillator type. Let's take a look.
One oscillator actuals changes the mix between prime and non prime partials. Blade does the same thing by providing a number of presets but in Razor, the mix of primes and non primes is a parameter. The Pershing Hoover sound makes it into the oscillator choices to no doubt appeal to a pop electronica market. You have 3 oscillators that simulate pitch bend adding an interesting sonic pallet not found in Blade. Pitch bend in Razor is done through oscillators and it a shifting of partials not real pitch bend. You have 2 oscillators that provide an interesting parallel to noise generators in analogues but with a spectral flavor and lastly a formant shaper which parallels Blade's ripples although is far more complex.
Blade's filters are pretty much standard fair although a bit broader than most synths offering low pass, band pass and high pass each in 12, 18 and 24 db cutoff but also a comb and a formant like filter called "vocal". All of Blade's filters are analogue in contrast to Razor that rarely leaves the additive realm.
Razor also has two sets of filters with different filter types in each bank. All of Razor's filters have a filter smoother to (I suspect) reduce some of that buzzy character of additive models based on broadband waveforms. Razors low pass filters are far more flexible than Blade's and feature continuous variable filter cutoff no doubt a by product of staying in the additive universe. There are 3 shapes of, something with ripples in resonant peak resembling a hybrid between LDF and comb and is evidenced by it's name low pass phaser and a dirtier grittier filter. There is what resembles a variable band envelope modulated filter, three types of formant filters (one with specific vowels) a vocoder.
The second Razor filter bank is more if the standard collection of garden variety filter fair, low, high, band, a few types of comb, a combined filter phaser, waterbed (yes, the filter visually looks like ripples on water and has a very organic sound, very cool). There is also a spectral pitch bend filter and a filter to emulate several instruments played at the same time.