by Craig Anderton
iZotope’s Ozone has been a mainstay for “in the box” mastering engineers since the very first version appeared. But as computers became more powerful, some adventurous types started using Ozone as a plug-in for individual tracks. While that certainly had its merits, due to its appetite for CPU cycles Ozone wasn’t really optimized for multiple insertions on multiple tracks; perhaps even more importantly, its functionality was optimized specifically for mastering, not mixing. So, iZotope put Ozone on a diet, changed the focus to mixing, and created Alloy—sort of an “Ozone’s Greatest Hits,” but created specifically for multitrack mixing applications.
However, since Alloy’s introduction, many DAWs now include channel strips or plug-ins that are on a par with other third-party plug-ins. Not to be left behind, iZotope has released Alloy 2—so let’s see if the concept is still relevant.
Alloy 2 has seven main modules: Equalizer, Transient Shaper, Exciter, two identical Dynamics processors, De-Esser, and Limiter. A signal flow graph lets you arrange these serially in any order (although dynamics can also go in parallel; more on this later), which underscores why two dynamics processors were included—you can compress signals going into the chain, and also compress at the end to smooth out dynamics changes caused by any other processing. This also allows one of my favorite techniques, which is putting two dynamics processors in series, set for very light compression; the sound is often more transparent than trying to “do it all” with one compressor.
Alloy 2 also comes with lots of presets, both for individual modules and overall setups. Although I usually build presets from scratch—every recording or mixing situation is different—the presets are helpful points of departure for those who find programming their own effects daunting.
Now let’s see what each module brings to the party.
This has eight bands, with a rich selection of responses for each band: Two “Bell” (peak/notch), three responses each for low shelf and high shelf, four lowpass and highpass types, and traditional Baxandall high and low shelving responses. This EQ definitely offers more than the typical EQ bundled in a DAW (Fig. 1).
Fig. 1: The main EQ features are eight bands, and the option to choose multiple responses for each one. Note the real-time spectrum display in the background.
In single-band mode, this has two controls (Fig. 2). Positive Attack values sharpen attack transients, while negative values soften them. A sustain control lengthens or tightens the decay; the audible results are somewhat like compression or expansion respectively, but with a somewhat different character.
Fig. 2: The Transient module is good for emphasizing percussive instruments, but can also soften attacks so they sit more in the background. This shows the single-band mode.
More importantly, there’s a multiband mode with up to three bands so you can shape transients in different frequency ranges differently.
This combines an Exciter function, which is basically saturation, and stereo widening effects in your choice of single-band or multiband modes (Fig. 3). Each of up to three bands can select a blend of four different types of saturation, the amount of drive going into the saturation, and the mix of the saturated and dry sounds. The Width control sets the stereo widening effect, and of course, you can select the frequency ranges of each band. There’s also a separate high shelf so you can both increase sparkle in the lower part of the highs, but reduce the topmost part.
Fig. 3: The Exciter provides controller amounts of distortion and stereo width enhancement.
With Ozone, the Exciter has been my “secret mastering weapon” for quite a few cuts, but only when used in minute amounts—think of it as the audio equivalent of a homeopathic remedy. It can add definition to the mids and sparkle to the top, and even increase low-end growl a bit if your favorite Scandinavian death metal band needs it. Also note that the Width control, when set to negative values, can be a “narrow” control which is great for centering the bass in mono. Once you learn how to apply it, this is an exceptionally useful module.
Here’s another “goes the extra mile” module. Like the Exciter, it can be single- or multiband (again, up to three bands), and these bands can be different for the two modules. It has all the expected controls—ratio, threshold, hard/soft knee, attack, release, auto gain makeup, etc. so let’s just consider what it does differently (Fig. 4).
Fig. 4: The two dynamics modules are extremely versatile.
There are two characters, digital and vintage. The difference isn’t huge, although the vintage mode’s action seems a bit less “tight” as the release is non-linear and program-dependent.
Individual gain and mix settings can be per-band or global; mix is particularly handy for me, as I’m a fan of parallel dry/wet compression. An extremely cool and highly unusual feature is that sidechaining is available for the entire compressor, or each individual band. These can choose individually from an external source, or from any other band—for example, the sidechain source for the high band could be the mid band. Still not enough? The overall detection circuitry has resonant highpass and lowpass filters that allow shaping the high- and low-frequency responses for the sidechain.
What’s more, you can place both dynamics processors in parallel within two constraints: they both have to be either single-band or multiband, and if multiband, they need to have the same frequency bands.
This is pretty straightforward (Fig. 5), although it offers the options for broadband or multiband mode (as more commonly needed for de-essing). Multiband lets you define the band limits within which de-essing occurs, and there are also attack and release controls. A nice touch is that the meter can optionally show a histogram instead of just the amount of reduction happening in the “reduction band.”
Fig. 5: The De-Esser is one of the more straightforward modules.
Yes, you can “sausage” your waveform if you want. The limiter has threshold and margin (the amount in dB between the limiter output and the maximum available headroom), as well as a “speed” control, which seems to set the slewing of the limiting action (e.g., primarily the release action). Like the de-esser, the meter can show a histogram.
The coolest feature here, though, is the appropriation of the Ozone waveform display which shows at any instant how much reduction is being applied, and to which peaks (Fig. 6). This is an extremely helpful reality check and while it’s generally not a good idea to listen with your eyes, this puts you “in the ballpark” a lot faster than relying solely on your ears.
Fig. 6: Note the display along the top that graphically shows how much peaks are being reduced.
A more unusual feature, the “phase rotate” option, is intended primarily for voice and narration. It alters a waveform’s phase to reduce waveform asymmetry; this lets you get a little more level, as you don’t have the positive or negative waveform peak defining the maximum available level because these are evened out more.
There are a ton of little extras in Alloy 2; really, too many to mention here—so download the trial version, and see if you can find them all. For example, a History button makes it easy to retreat through your editing moves if you went too far, and the innocent-looking Options button brings up various Cool Stuff for each of the modules, as well as for the meters and spectrum display. For example, with the meters you can choose the metering response and scale, hold time, and the like; there are also a lot of general setup features. In the multiband processors, you can choose whether to have 1, 2, or 3 bands (although why you’d choose 1 baffles me, given that you can just choose single-band mode).
So it’s time to answer the original question of whether Alloy 2 brings processing options sufficiently different from whatever your DAW includes to merit the expense. As far as I’m concerned, the answer is yes. While many programs have many of these modules, Alloy 2’s strength is its depth—like the EQ offering eight bands with multiple responses instead of the usual four-band parametric you’d expect to find, and the multiband operation for the exciter, dynamics, and transient shaper.
In essence, iZotope has produced a “mastering suite” for individual tracks that offers both flexibility and detail. It will likely take quite awhile before the average DAW’s bundled effects catch up with what Alloy 2 can do—but by then, we’ll probably be reviewing Alloy 3.
Craig Anderton is Editor Emeritus of Harmony Central and Executive Editor of Electronic Musician magazine. He has played on, mixed, or produced over 20 major label releases (as well as mastered over a hundred tracks for various musicians), and written over a thousand articles for magazines like Guitar Player, Keyboard, Sound on Sound (UK), and Sound + Recording (Germany). He has also lectured on technology and the arts in 38 states, 10 countries, and three languages.