Recording - September 2011 - 38

PLUG-IN OUTLET
Little Endian SpectrumWorx 2.4
By Mike Metlay

weeks and I’m still not sure I understand the difference between a Hann Window and a Blackman Harris Window! But it’s worth experimenting with the settings to determine what sounds best to your ears and/or lets any given preset run with the least load on your CPU. You might not understand what overlap factor or frame size are, but their effect on audio quality and processor load can be dramatic. Note that Engine settings can be set differently from preset to preset; usually there aren’t hiccups when you change patches, but some DAWs might get confused, resulting in clicks, pops, or loud transients. The modules From the get-go, Little Endian makes it clear that a lot of the “effects” you’re used to seeing in plug-ins, like reverbs and choruses and so forth, aren’t part of the SpectrumWorx tool kit. The modules all offer signal processes that work in the frequency domain; they alter the spectral content of audio fed to them in various ways. It’s not always easy to tell what a given effect module does from its name, but the manual walks you through them and a quick test usually demonstrates what they sound like. The first class of modules are the Pitch modules, which alter the pitch of the input signal either according to directly set front-panel controls (like the plain Pitch Shifter) or according to the pitch content of the sidechain signal. You realize you’re not in Kansas any more when you see TuneWorx, an Auto-Tune-like module that lets you select pitches by semitone and shift incoming audio to the nearest one (including deselecting certain pitches to force input audio to a given scale), casually mentioned and dismissed in three lines in the manual! Other modules include weirdnesses like Sumo Pitch, where the main and sidechain audio are pitch-shifted toward each other “like Sumo wrestlers”, and Pitch Spring, where you can “bounce” pitch away from its input value in an oscillation that can go sharp, flat, or both. Timbre modules include filters, Ah-Ah (a modulated wah effect), and modules to smooth or sharpen frequency content. The odd ones here are Tonal and Atonal, which as their names imply, let through highly tonal peaks in the audio content and suppress the rest, or vice versa. The Time modules work with how the input signal is heard in time; they can introduce more latency than other modules simply because they can involve significant delay time to do what they’re designed to do. The classic example here is the Reverser, which takes an input signal, chops it into chunks of a certain length, and plays back the chunks in the proper order but with each chunk played backwards. There are also modules to slice up audio and mix it with silence or the sidechain signal, and a truly bizarre pair of frequency-based compression and expansion modules called the Imploder and Exploder. The Space modules are echoes and reverbs... but this being SpectrumWorx, every single echo

Ever heard of Little Endian? This little company in Zagreb, Croatia, is responsible for the release and development of a modular sound processor plug-in called SpectrumWorx, a project it took over when it acquired original developer Delaydots. In just over a year since its initial release, SpectrumWorx has added a slew of user-requested features while making the jump from Windows-only to add Mac OS X support and now a software developer kit for iOS. With its popularity spreading rapidly and its utterly unique approach to effects creation getting a lot of attention, I was looking forward to taking it out for a test drive and seeing what all the fuss was about. I reviewed version 2.4, which comes with an excellent set of new presets from sound designer Martin Walker to add to its already impressive library; by the time you read this, version 2.5 will be out, with new modules like Convolver and Time Freeze. But we’re getting ahead of ourselves.... What’s this all about? SpectrumWorx is a modular environment for sound processing and design; Little Endian affectionately calls it “the ultimate sound mangler”, and there’s some substance to that audacious claim. The plug-in consists of a series of over 50 sound processing modules with a uniform user interface design that are then plugged into a virtual rack. As you can see in the screenshots, the plug-in presents a very clear and simple interface. On the right is the Module Rack, holding up to five modules, each with its own knobs and pulldown menus, a lit icon to activate or bypass it, and an X icon to delete it. Clicking on the arrow to the right of the last module brings up a set of dropdown menus to add a new module to the rack, and modules can be easily reordered via a simple drag and drop. On the left is the Main Window, which has input and output and wet/dry mix knobs, and a detailed set of information on whatever parameter you’ve selected most recently: the current value, settings for an LFO to automatically modulate it (yes, every knob on every module has its own LFO!), and upper and lower limits on its range for this preset. There’s also a place for external audio from an existing sound file to be fed into the plug-in as a sidechain modulation source. You can use ordinary WAV or MP3 files (as long as they’re small enough to fit into RAM); I had fun using impulse responses from Spirit Canyon Audio (www.spiritcanyonaudio.com) for many of my tests. If you want to choose, save, or delete presets, a floating window pops up with controls to do so; a second floating menu gives you settings for the DSP Engine, user interface, and registration information. For example, this is where you set up mono or stereo I/O, with or without a sidechain. If your DAW supports sidechain input, SpectrumWorx can use it instead of a fixed external sound file. Some of the Engine settings are strictly for the technically-minded. Despite the manual’s detailed explanations, I’ve been working with SpectrumWorx for
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RECORDING SEPTEMBER 2011

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Recording - September 2011

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