Wavetable synthesis. I can’t think of another synthesis type that has given way to quite so many different ideas and approaches. From where I’m standing, when it comes to wavetable synthesis it’s all about workflow. The Four Seas is nascent Finnish developer Ferry Island Modular’s contribution to this discussion: their debut module, it’s a bold statement of intent, joining a litany of synths and modules from companies large and small that each present their own thesis on how to best access this strangest means of synthesizing sounds.
A ‘four‑dimensional’ wavetable oscillator, the Four Seas can, in its creators’ words, “transform sound exploration into a tactile, intuitive experience” by allowing you to explore wavetables as a ‘three‑dimensional cube’. The idea is this: three primary controls, X, Y and Z, represent three axes across which you can choose a position within one of 12 8x8x8 cuboid wavetables. From this fundamental position, three additional controls for X Spread, Y Spread and Z Spread allow you to incorporate subtly — or not so subtly — deviant positions, with the resulting four signals sent out via the four outputs. I should also say that this 26HP module is really a lovely thing, physically speaking. Its matte‑black textured faceplate belies the nautical theme with gold, plant‑like graphics with LED leaves (or are they petals?). Its panel is on the large side, for sure, but I cannot fault the interface, which is both spacious and economical.
Wavetables
The Four Seas’ factory wavetables range from basic waveshapes to samples of machinery to vintage arcade sounds (it is also possible to load custom wavetables). These are well selected, I must say: from warm and mellow chiming tones to reedy, razor‑sharp sounds, things can switch from gentle to abrasive very quickly. Indeed, what really makes the whole thing come alive is the fact that it gives four lots of opportunities for movement, which is of course critical when it comes to using wavetables. More often than not, a static position doesn’t make for the most interesting sound, but involve even a little movement and a trove of dynamism can present itself. Here, one wavetable can provide four different distinct versions of itself simultaneously; and since all three Position controls and all three Spread controls have their own CV inputs (the former with attenuverters), if you have the modulation capacity in your system you can generate some seriously dynamic morphing sounds. I will say that naming the outputs 1, 2, 3 and 4 but everything else X, Y and Z doesn’t make for the most intuitive relationship, but it gets the job done.
The four outputs’ efficacy extends beyond wavetable position: there’s another type of Spread — Frequency Spread — which means the oscillator can be spread into four individual pitches, which are then sent to the four different outputs. This can look like subtle, chorus‑like detuning or fully chordal results. Once again, I can’t help but wonder if the semantics could have been different here to help with the workflow, but hey ho. The Spread Mode knob presents eight different quantisations to choose from; these range from just intonation to Pythagorean fifths to tuning based on the Fibonacci sequence. The Spread amount is also CV‑controllable, as is wavetable bank selection, so once again movement is encouraged — I found dialling in subtly undulating chorus to be intriguing, but patching a random stepped voltage to the Bank CV input was positively brilliant, spitting out all manner of off‑kilter harmonics. This is of course beyond the primary Volt‑per‑octave input and accompanying FM CV input. I don’t think I’ve come across an oscillator with quite so much inherent potential for adventures in frequency — melodically quantised or no. One thoughtful touch in this department is a Lock button next to the tuning knob, to prevent accidental changes in master pitch. Maybe it’s my clumsy fingers or baggy sleeves, but I appreciated this greatly.
Modulating even two thirds of the Four Seas’ parameters at once, I’ve no doubt I could centre an entire ambient set around this one module.
As if the whole ‘movement’ thing couldn’t be hammered home any more by the Four Seas, on the other side of the panel there’s more. Just above the outputs are a brace of inputs for modulating the oscillators, along with attenuators and buttons for choosing one of three modulation modes. LFO mode drops things to sub‑audio rates to become a very complex but usable modulation source to send elsewhere (or internally, of course). It’s also possible to add sync into the mix for outputs 1 and 3 — hard sync, soft sync or ‘flip sync’ waveshape reversal. Modulating even two thirds of the Four Seas’ parameters at once, I’ve no doubt I could centre an entire ambient set around this one module.
The list of designers offering their various takes on wavetable synthesis is growing apace; but if (as I believe it is) wavetable synthesis is indeed about workflow and movement, the Four Seas does both better than most. Keep an eye on Helsinki: there are exciting things afoot.