When the coding masterminds at Wave Mechanics recently spun off a more division called SoundToys, their concept was to produce a line of Digidesign Pro

When the coding masterminds at Wave Mechanics recently spun off a more “playful” division called SoundToys, their concept was to produce a line of Digidesign Pro Tools plug-ins that didn't simply model old gear, but rather manipulated and mangled sound in ways more akin to sound design than traditional effects. Creating a new generation of dedicated processors that would provide all of the flexibility and creativity of digital, possess a distinct analog character and vibe and deliver it in top-drawer sound quality became the company's modus operandi. Incidentally, these are the people who were responsible for designing such groundbreaking and industry-standard products as the Eventide H3000 and DSP4000 Ultra-Harmonizers, the Wave Mechanics UltraTools line of TDM plug-ins and the DSP algorithms for TC Electronic's FireworX.

Although the series is projected to be eight titles strong, FilterFreak Creative Resonant Filter and PhaseMistress Analog Phase Shifter are the first to roll off the line. Environmentally packaged in smart little circular tins, the contents of each include only an installation CD, an iLok license card and a SoundToys card containing the serial number required for product registration. On disc, in lieu of a hard-copy version, is a fun, thorough and easy-to-read Acrobat PDF of the manual. Minimum system requirements for both titles, according to Read Me files, are a Mac 500MHz or greater running Mac OS X or 9.2, Pro Tools TDM or LE 5.0 or later and an iLok USB hardware key for software authorization.

Currently being developed exclusively as native plug-ins, both run as an RTAS, HTDM or AudioSuite process. The folks at SoundToys assure that they're hard at work on TDM versions, which should be available by early summer, and that they'll be offering registered customers free TDM support at that time.

Installing the plug-ins on my Mac G4 dual 1.25GHz, equipped with 768 MB of RAM and Mac OS 10.3.2, was fast and painless — as it should be with iLok apps. With nothing to type in, each took less than 15 seconds to install and validate, and that's including the time it took to remove the chip from the license card and insert into the iLok.


Sharing some rugged, retro good looks, both plug-ins give you the secure impression that you're dealing with something analog. Near-functionally identical, each makes use of realistic knobs, toggle switches, LEDs and parameter “nudge” buttons, all with an excellent look and feel and intuitively laid out with the cosmetic flare of a vintage rack.

FilterFreak and PhaseMistress are broken down into essentially three main sections: filters/frequency, modulation and input/output. What became evident only after several hours of use were the intelligent and extremely well-thought-out decisions that the designers made in what to hide from the operator in the user interface. To keep things streamlined and simple, they only present you with what you need, when you need it, instituting mini pop-up windows for specialty functions and in-depth parameter tweaks. In other words, a quick glance at the simple faceplates are a misleading representation of the power buried within.

Selecting FilterFreak as an insert device for the first time revealed a nice treat: the option to choose between FilterFreak1 or FilterFreak2, a single- or dual-band version of the plug-in. The 2-band version is identical to FilterFreak1 except that it shifts things around a bit to make room for the second filter. The filters themselves are identical but can be set independently of each other, assigned in series or in parallel and linked to move in unison or offset. Both plug-ins have hundreds of factory presets and make use of the standard Pro Tools menu to handle bypass, compare and parameter-automation functions.


By virtue of the functional similarities between the two plug-ins, learning one will have you flying around both in no time. Each starts out with a simple I/O stage consisting of Input and Output attenuation knobs and accompanying LED meters, complete with an intriguingly labeled Analog Mode switch. By default, the plugs come set up in a pristinely clean “digital” mode, with the typical drawback that higher signal levels clip in nasty ways. Although that kind of grating distortion can be fun and useful, switching over to analog mode — besides munching up considerably more CPU cycles — distorts or saturates in nice, warm, friendly tones as the signal input increases, similar to the way that real analog gear responds.

The two level-control knobs are particularly useful in analog mode, allowing you to push the input level well beyond 0 dB and smoothly control the amount of saturation, distortion and compression applied to the signal. In this mode, you also have a selection of several analog flavors from which to choose, but more on those later.

From the input/output stage, jump straight into the frequency section. In FilterFreak, as expected, the Frequency knob is probably the most important control of the entire plug-in. With a total range of 20 Hz to 20 kHz, it determines the area or region of the overall sound spectrum affected by the filter, which is available in lowpass, bandpass, highpass or band-reject/notch modes, as selected by the adjacent Shape knob. Filter slopes range from the classic and mild-mannered 12dB/octave (2-pole) all the way up to the supersteep 48dB/octave (8-pole) in increments of 12dB/octave. Self-oscillation is always tasty, and FilterFreak's Resonance knob can trash your speakers with the best of them, so be careful. Lastly, visual feedback of your frequency carving is displayed on a handy animated scopelike display that bounces along to show the effects of any modulation that you might have going on in the background.

The Frequency knob handles things slightly differently in PhaseMistress, as it allows you to set the “center” frequency of the phase notches, essentially tuning or biasing the phaser's effect toward certain frequencies. It determines the point along the frequency spectrum that the phaser effect will be centered, sometimes referred to as the “initial setting.” By cranking the Resonance knob, in this case, you create resonant peaks in each of the notch filters, boosting and enhancing the harmonics contained in the input signal that fall around each of the notches, creating a “churning” phaser effect. In place of the poles and shape controls found in FilterFreak, PhaseMistress comes equipped with a Styles page, giving you access to dozens of different virtual phasing “circuits,” each having a completely different tonal shape, while preserving frequency and resonance.

The party really starts cookin', though, when you pump things through FilterFreak's totally sick modulation section. There, you're presented with a choice of six different modulation modes. First, there's an LFO (0.1 to 100 Hz) with the choice of six standard wave shapes, as well as the ability to create custom shapes by adding and moving points along a curve. Further modulation modes include an envelope follower for Mutron-style dynamic filtering, a classic random sample-and-hold generator, manual/MIDI note- or threshold-triggered random step and ADSR modes, and a highly advanced rhythmic mode. The mod interface changes appearance to reflect the selected mode. A really cool and unique feature in FilterFreak's mod section is the Tweak page, in which you can individually adjust the depth and direction (positive/negative) of modulation applied to the frequency, resonance and output.

PhaseMistress addresses tweaking in two ways with a similar Modulation Tweak section and a Style Tweak section, essentially letting you dig into the structure and guts of the virtual phasing circuitry. This extremely powerful feature sets PhaseMistress apart from traditional phasers by letting you select the number of stages and the phase (in/out) of the filter resonance (among other deep parameters), significantly affecting the character and tonal quality of the wet signal. Speaking of which, the Mix knob behaves in the same manner for both plug-ins, controlling the balance between the effected sound and the dry signal. Interesting to note here is that the input and output controls of both plug-ins advantageously only affect the treated signal, leaving the dry signal unchanged and making it easy to mix tonal characters.


One of the coolest modulation-section features on both of these plug-ins, by far, is Rhythm mode, in which it's possible to synchronize the LFO (regardless of shape) to the MIDI Beat Clock in Pro Tools or tap tempo, which works very well when no MIDI Clock is available. Bpms may be entered manually, as well. The result is a plug-in that totally hip-hops and grooves along with your audio. Provisions are given for selecting from preset rhythmic intervals and LFO shapes, or you can choose to roll your own in the custom Rhythm Pattern Editor. The Rhythm Pattern Editor works somewhat like a simple drum machine. By default, the basic rhythm pattern is one bar long, but you can alter the length in bars, adjust beats per bar and define the rhythmic grid down to 32nd-note resolution. For screen space, only one bar is displayed at a time. Each event in the pattern triggers one entire cycle of the LFO shape. And you can generate complex rhythms by adding events, stretching and compressing their individual levels and durations.

Although every step event in a pattern must contain the same LFO shape, the ability to edit a custom shape is really cool. There's absolutely no limitation to the complexity or style of rhythm with which to drive FilterFreak or PhaseMistress. In fact, the more you futz with the Rhythm and Shape editors, the more likely it is that happy little accidents might occur as frequencies and resonances dance, burble and slide around in front of you. Oh, and the shuffle/swing Groove function is really sweet!


Using these two plug-ins was a complete love-in from the get-go, so I can't help but gush about them. They just sound so damn good! Adjectives I'd use to describe them go way beyond the expected warm and fat to truly jaw-dropping, goose-pimple-inducing levels of creative inspiration and excitement. The Freak's filters are the closest to analog you'll get in a plug-in. The character sits somewhere between the smoothness of a Moog Minimoog and a harder-edged unit like a Sherman Filterbank. And the Mistress? Well, she be smooth. It's amazing what 24 stages will do for a phaser. The presets cover both traditional and not-so-traditional (that is, “drum mangling”) categories, and PhaseMistress, in particular, scores high with its rock-solid emulation of classic pedals.

Kicking the plugs into analog mode and dialing up a flavor puts the warm and fuzzies all over your sound. Analog flavors in both FilterFreak and PhaseMistress include: Clean, for a maximum nondistorted range of beautifully subtle saturation; Fat and Squash, for smooth low-frequency distortion and compression; Dirt, for general broadband saturation; Crunch and Shred, for adding lots of high-end clipping mayhem; and Pump, for extreme compression. It should be noted that all analog settings add a certain amount of distortion at all signal levels.

When you overload the inputs in analog mode, things get really cozy. In fact, the flavors almost beg you to overload more and more and more. FilterFreak's filters love the warm compression, and I shouldn't even have to tell any guitarists who might be reading this how healthy doses of distortion are what make a phaser shine — this “filter box” was quickly becoming my favorite new compressor. Placing Crunch on a drum loop did gorgeous things to the bass drum, adding a subtle liquid ring, affecting more of the upper mid and leaving the bass alone. I really loved Shred on breaks — can anyone say the Crystal Method?


Every so often, I have the pleasure of coming out of a review feeling completely stimulated and blown away by a new product. But maybe I should qualify this first: FilterFreak and PhaseMistress — perhaps their coy names, alone — didn't exactly send me racing to rip open the package and try them out when the courier arrived. Admittedly, I was ho-hum about them, thinking, “Okay, just another filter and phase-shift plug-in.” But the obvious attention that's been given to making them sound and respond so much like real analog equipment, together with the extraordinary time and effort that SoundToys has put into the features to make them behave unlike any other gear or software I know of, really won me over. I love the fact that either one can turn the completely mundane into sonic Ibiza. In fact, I'd classify these as today's must-haves for every remixer and sound designer — no bull.

Analog mode seriously clamps down on slower CPUs, but it barely put a dent in my dual G4 test system. Latency and the possibility of cancellation when used on an aux bus is an issue with any RTAS or HTDM plug-in, so my only con would be that they're not available in TDM yet. But with TDM versions on the way, I can hardly find it in myself to print any negatives about these truly wonderful plug-ins. In fact, to sweeten the offer even further, SoundToys informed me that by the time this review goes to print, it will be offering two new plug-ins, Crystallizer (the granular echo effect first heard in the classic Eventide H3000) and Tremolator, bundled together with FilterFreak and PhaseMistress as a four-pack called UltraFX 1.1, which will sell for $399. Crazy!

Thanks to Edmund Eagan at Twelfth Root Inc., Ottawa, for his assistance in this review.

Product Summary



Pros: Excellent dual-band filter and phase-shift emulations. Deep, analoglike character and sound. Advanced rhythmic modulation. Great tools for sound design.

Cons: None.

Contact: tel. (802) 951-9700; e-mail; Web

System Requirements

G4/450; 256 MB RAM; OS 9.1 or later; Digidesign Pro Tools 5.0 or later; iLok key