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iZotope Ozone 7

Mastering Suite For Mac OS & Windows By Paul White
Published February 2016

iZotope Ozone 7

Version 7 of iZotope’s mastering package adds cutting-edge codec monitoring features as well as vintage-themed processors.

iZotope’s Ozone, now on its seventh version, aims to provide the Mac OS or Windows computer-musician with a complete set of mastering tools. Available in Standard and Advanced versions, Ozone 7 can be used either stand-alone or as a DAW plug-in in RTAS, AudioSuite, 64-bit AAX, VST 2, VST 3 and Audio Units formats. In the stand-alone version, Ozone can host third-party VST and AU plug-ins, and can open multiple audio files within a single session. The Advanced version also makes Ozone’s component parts available as a suite of separate plug-ins, and incorporates a number of modules and features that aren’t available in the Standard version.

Most of the new additions in Ozone 7 are available only in the Advanced version. They include Vintage Tape, Vintage EQ, Vintage Compressor and Vintage Limiter modules, plus a Codec Preview feature, new file export format options and an upgrade to the existing Maximiser. In all, Ozone 7 Advanced comprises 10 modules plus the additional Insight, a comprehensive metering plug-in presented in ‘night-vision green’ where you’ll find a 3D spectrogram, a stereo Sound Field, a Loudness History, Spectrum Analyser and level metering plus loudness metering displayed in LUFS.

Each Ozone module comes with its own presets, but there’s also a Preset Manager offering global presets that can draw on any or all of the modules and routing options in combination. The Greg Calbi Mastering Presets for Ozone package is now included as standard. Once a preset has been loaded, settings for the individual modules can still be saved or loaded without losing the setting on the other modules. While I’m not a fan of using presets ‘out of the box’ for mastering — the preset designer has no way of knowing how loud, dynamic, bright or boomy your original track or mix is — looking at how a preset is put together can be very educational.

Ozone’s Undo History allows you to go back if things get messed up, and there’s an A/B comparison function to let you compare two different settings to see which works best. Importantly, you can also engage a constant level function so that when you engage Ozone 7 the subjective level stays the same, allowing you to make meaningful comparisons.

Ozone received a major user-interface overhaul in version 6, which was reviewed in SOS June 2015 ( The new look is generally tidy and approachable, though I found some of the grey-on-black text very difficult to read outside a darkened studio.

Vintage Vibes

As their names suggest, the focus of the new tools in Ozone 7 Advanced is on creating an analogue-like ‘vintage’ sound. For example, the Vintage EQ behaves somewhat like a Pultec, the Vintage Compressor has a definite analogue feel, and the tape emulation is, naturally, based on an analogue machine (a Studer A810).

The Advanced-only Vintage Tape module is a good example of Ozone’s straightforward GUI layout, being presented as a set of sliders with no animated tape reels or other eye candy to distract the user. It offers a choice of 15ips or 30ips virtual tape speeds and models all the desirable ‘flavour’ characteristics of tape, but without adding unwanted hiss or tape speed errors such as wow and flutter. Unless the parameters are taken to extremes, the effect is appropriately subtle, adding an analogue-like warmth and smoothness to the sound, though abusing the Drive, Bias and High Emphasis parameters can also add some quite aggressive grit.

Similarly unfussy is the Vintage EQ,Simple but effective: the new Vintage Tape module.Simple but effective: the new Vintage Tape module. again only available in Ozone 7 Advanced. The controls are set out much as on a vintage Pultec, but a distinct advantage is the addition of an EQ curve display, something that many of the more purist Pultec plug-in emulations could benefit from. Being a passive EQ followed by a gain buffer, the original Pultec exhibits a lot of interaction between the controls, and not always in a way that is entirely intuitive. With the frequency curve display you always know exactly what your tweaks are doing, especially in situations where the separate bass cut and bass boost sliders are used together to enhance the lows while also cutting out boominess in the higher bass regions.

Like the original, the Vintage EQ paints in broad strokes, delivering a smooth, analogue-style sound that is well suited to polishing master recordings in an inherently musical way. It doesn’t have the forensic capabilities of a parametric EQ but then you get a separate parametric EQ for those jobs. There’s also an M-S mode where different EQ settings can be applied to the Middle and Sides signals by clicking on the Mid or Side buttons.

Good Character

The new Vintage Compressor module is also available only in Ozone 7 Advanced, and is a single-band compressor that works best for subtle dynamic range control. It too may be used as a conventional stereo compressor or in a Mid-Sides configuration, where different compressor settings can be applied to the Middle and Sides signals. Employing a feedback topography, the Vintage Compressor features a program-dependent release time that responds to the dynamics of the input signal; in a nutshell, you set the release time that you feel works best, and then the compressor tweaks your setting on the fly to match the material. The Vintage EQ takes its sonic cues from the classic Pultec designs, but follows iZotope’s own visual themes.The Vintage EQ takes its sonic cues from the classic Pultec designs, but follows iZotope’s own visual themes.

As well as conventional controls for adjusting Threshold, Attack, Release and Gain (with an Auto option that maintains a constant level as you adjust the compressor), there’s a switchable side-chain filter with adjustable low-pass, mid-peak and high-shelving bands that can help replicate some of the foibles of classic compressor side-chains. Further to these controls is a choice of Sharp, Balanced or Smooth characters that, from viewing the scrolling gain-reduction graph, seems to affect the overall rate of response. The gain-reduction plot can be displayed as an alternative to the side-chain filter curve, superimposed on the waveform of the material being processed. The display is clearly ‘busier’ in Sharp mode but tends more towards gentle levelling in Smooth mode. The ratio can go as low as 1.1:1, making it ideal for the low-ratio, low-threshold ‘glue’ settings that are often employed during mastering.

Vintage Limiter is included in both Standard and Advanced versions. Apparently inspired by the Fairchild 670, it is an evolution of the Tube limiter mode in Ozone 6.1, with additional parameter adjustments including a choice of Analogue, Tube or Modern characters. A Character slider adjusts between fast and slow response times. The three different modes on offer dictate how the limiter responds in the saturation zone that precedes hard limiting, with a significant influence on the overall sound and on the impression of loudness. There’s a scrolling waveform-plus-gain-reduction display, and presets made with Ozone 6.1’s limiter in Tube mode are compatible with this new version.

Max Factor

Elsewhere, the existing Maximizer has been upgraded in both the Standard and Advanced version, with the addition of a new Intelligent Release Control mode called IRC IV that uses spectral shaping to help maximise loudness without losing transparency and without allowing clipping to occur. Apparently the design aim was to reduce the way transient detail typically is pulled back when low frequencies, such as kick drums, trigger gain reduction, and it achieves this by adding emphasis to transients during gain reduction.

Though the Maximizer is normally used as a stereo processor, it is possible to process the left and right channels separately by selecting Stereo Unlink. A Gain Reduction Trace meter display scrolls along with a waveform display so that you can see when and how much gain reduction is being applied.

Ant & Codec

There’s one more major new feature in Ozone 7 Advanced. Called Codec Preview, it appears to do a similar job to the Fraunhofer Pro-Codec plug-in from Sonnox, providing a real-time preview of how your mastered track might sound after being subjected to MP3 or AAC compression. Such compression can often increase peak levels, meaning that a mix which is otherwise not clipping might do so after conversion; if this happens, Codec Preview gives you a real-time warning so that you can reduce the level of your master prior to encoding to compensate. There’s also a mode to audition the difference signal generated by comparing the compressed and uncompressed versions, so you can hear just what artifacts are being added. These are usually most noticeably on wide stereo mixes so you also have the option of adjusting your stereo balance to minimise the side effects of compression. Once you’re happy with your mastered mix you can then export it in MP3, WAV or AAC formats complete with metadata such as track name, band name, album name and so on.

Going Forward

Ozone 7 is a worthwhile evolutionary step up from previous versions, notable not only for the sonic capabilities of the various modules, but also for its wealth of excellent display and metering options. Having some new vintage flavours to bring into the picture is very welcome, as is the addition of Codec Preview. I’m glad that the designers have resisted the temptation to overdo the vintage character: these new effects are suitably subtle, just as they are with typical vintage hardware. My only mildly negative grumble is the rather irritating use of black text on a fairly dark grey background in many places, and though other companies also adopt this ‘style over function’ approach (Apple’s Logic Pro, for example), it’s hard on the eyes when working in a brightly lit environment.

As an all-in one mastering package then, Ozone 7 offers all the tools you’re likely to need and it does so without making any of them over-complicated. You still need some expertise to get the best out of it, but if you take the time to check out some of the presets to see what makes them tick, you should get the hang of it very quickly.


The main all-in-one alternative to Ozone is probably IK Multimedia’s T-Racks mastering suite, which offers a similarly comprehensive range of processing modules. If you are working within a DAW host, you could also check out mastering plug-in bundles from the likes of FabFilter, Flux and Sonnox.

Dynamic EQ

The Vintage Compressor can emulate a  variety of classic compressor characteristics.The Vintage Compressor can emulate a variety of classic compressor characteristics.Both versions of Ozone now get the Dynamic EQ module, which was introduced in the Advanced version of Ozone 6. If you haven’t used a dynamic EQ before, it’s a hybrid processor that combines equalisation with an element of compression or expansion: the EQ boosts or cuts that you set up are varied in amount by the signal level once a threshold has been crossed, rather than being left at a fixed value as with a conventional equaliser. The six EQ bands can be populated from a choice of five filter curves including Baxandall Treble, Baxandall Bass, Proportional Q, Band Shelf and Bell, and a global choice of Analogue or Digital modes flips between minimum-phase and linear-phase filtering. Each band is selected for editing by a tab that displays the settings for that band including curve type, threshold, attack, release and Invert, which accentuates the boost or cut when the threshold is crossed rather than reducing it. There’s a choice of stereo or M-S operation, and the amount of dynamic cutting or boosting is clearly shown on the EQ curve graph. The attack and release times are manually adjustable for each band but can be set to automatic by selecting the Auto-Scale function.

Dynamic EQ is an extremely useful problem-fixer made even more versatile by the M-S option. For example, by treating only the Mid signal, it may be possible to reduce harsh audio peaks or sibilance in the vocal that wasn’t picked up at the mixing stage, without affecting what’s going on at the sides of the mix. Alternatively, in Invert mode it could be used to lift kick drums or snare hits out of a flat mix.


  • New suite of vintage-themed processors offers classy analogue-like sound quality.
  • Real-time Codec Preview function lets you hear how your mixes will sound once encoded to MP3 and AAC.


  • Interface text can be hard to read in some light conditions.


Ozone 7 is a thorough overhaul of iZotope’s flagship mastering package, giving users of the Advanced version in particular a lot of new processing modules and features.


Advanced version £339; Standard version £169. Upgrades from previous versions £169 (Advanced) or £66.95 (Standard). Prices include VAT.

Time + Space +44 (0)1837 55200

Advanced version $499; Standard version $249. Upgrades from previous versions $199 (Advanced) or $99 (Standard).