Oct 03, 2019 Production aficionados iZotope made a surprise announcement today with Ozone 9, the latest version of their flagship mastering software. Building on the past success of its plugins from the mastering suite—like an integrated Vectorscope and Correlation Meter, track referencing, and Master Assistant—Ozone 9 introduces some key new features for even more control. Learn how Ozone 9 can bring balance to your music with new never-before-seen processing for low end, real-time instrument separation, and lightning-fast work.
Ozone is a chemically reactive natural gas. It is usually created by sunlight high in the stratosphere where it takes part in the normal cycle of atmospheric chemistry. Unfortunately, ozone is harmful to living things at ground level, especially over long-term, repeated exposure. Sometimes air purification methods produce ozone as a byproduct or even use ozone as a primary method of cleaning the air.
Ozone is classified as a pollutant by the EPA, the WHO, and many other health organizations, so improving the indoor air quality in your home should not include adding ozone. What are the different types of air purifiers that produce ozone? Before getting to that, here is a look at why some air purifiers create ozone.
Studies have found some acute negative effects of short-term ozone exposure and increased mortality rates in cities during periods of increased ambient ozone levels (Gryparis et al., 2004). A review of ozone health effects reports that acute exposure may can cause “changes in lung capacity, flow resistance, epithelial permeability, and reactivity to bronchoactive challenges…Repetitive daily exposures over several days or weeks can exacerbate and prolong these transient effects.” (Lippmann, 2012).
While certain air purifiers release ozone as a by-product, other release it intentionally, claiming that ozone can be a method of purifying the air. Ozone is simply three oxygen atoms bound together to form an O3 molecule. It is a highly reactive molecule, which means that it binds with other compounds in the air or in your lungs, forming new types of molecules. Proponents of ozone air purification say this means the ozone breaks down harmful toxins in the air, converting them to other, less harmful types of molecules.
The EPA has done an extensive breakdown of how ineffective ozone actually is at air purification. It can be effective at breaking down certain chemical compounds in the air, such as some of the toxins found in tobacco smoke. However, ozone released from an ozone generator cannot remove other compounds in the air such as dust, pet dander or other allergens. It may take months for ozone to have any effect.
Ozone may even break compounds down into more harmful chemicals. Some professional cleaners use ozone to purify rooms, removing smells and killing bacteria, but they use extremely high concentrations of ozone and they have to air the room out, removing the ozone, before anyone can occupy it again. It is also well-known for its tendency to damage anything in the home with a rubber component, cracking and breaking the rubber into dust. The amount of ozone a home air purifier produces may not do enough good to outweigh the harmful effect of ozone exposure.
Here are some air purifier technologies that can produce ozone, either as a byproduct or as the primary method of cleaning the air.
Ozonators, or ozone generators, are often marketed as a “natural” way to remove odors or purify air. They generate ozone and directly release it into the air, creating high concentrations. Molekule agrees with the EPA that these should not be used in occupied spaces.
Electrostatic precipitation air purifiers remove dust and other particles from the air by imparting an electrical charge to these contaminants. Within the air purifiers are plates (or sometimes fibers) that are given an opposite charge. Opposites attract, so the charged particles are attracted to the oppositely charged plate, removing the particles from the air. While these air purifiers are somewhat effective at this, the process of adding an electrical charge to the air causes some free oxygen molecules to become ozone. Studies have found that electrostatic precipitation air purifiers can increase indoor ozone concentrations up to six times the outdoor level (Rim et al., 2014).
Ionizers are very similar to electrostatic precipitation air purifiers: they use a coronal discharge to put electrically charged ions into the air, which attach to particles, giving the particles a charge. The particles are then attracted to each other (because some of them will have positive and some negative charges, causing electric attraction). As the particles clump together they become too heavy to remain suspended in the air, and they precipitate out of the air to land on the floor, sofa, curtains or whatever other surface attracts them. In addition to this somewhat messy solution to air purification, ionizers have the same ozone generation problems as electrostatic precipitation air purifiers.
Air purifiers that use ultraviolet light to kill microorganisms (also known as UVGI, ultraviolet germicidal irradiation) only work against certain species. More importantly, they may also have a hidden danger. Small home UV-C air purifiers use a fan to blow air through the purifiers, where pollutants are briefly exposed to UV light while passing through. The hidden danger is not from the radiation (although you do need to be careful when using UV-C light). The danger comes from oxygen particles that are broken apart by the high-energy UV-C light. These atoms then combine again with other oxygen atoms to form ozone. Therefore, UV-C air purifiers are not ozone-free.
Not only do they produce ozone, they are not very effective in a residential setting. While studies have shown that high-energy ultraviolet light kills bacteria, viruses and some mold spores, to do so effectively requires very high-intensity UV light and a long duration of exposure. So these units offer neither the intensity nor duration necessary to be really effective. Plus, they do nothing to remove particles like dust from the air, so they have to be combined into hybrid systems with HEPA filters.
Photocatalytic oxidation (PCO) air purifiers are designed to remove gaseous pollutants from the air, though the effectiveness of this method has not been demonstrated. The filter surface is coated with a chemical catalyst which is activated by UV-C light. The resulting photochemical reaction creates hydroxyl radicals, and these molecules oxidize the pollutants that come in contact with the filter surface. Ideally, the chemicals break down into harmless CO2 and water. However, unless the PCO device is known to very efficiently produce the radicals in large amounts, it is impossible to control or predict exactly how completely chemicals will break down, so PCO air purifiers can form incomplete byproducts like formaldehyde, nitrogen dioxide and other harmful compounds (Hodgson et al., 2007). In addition, without a proper coating, the UV lamps used in PCO air purifiers can create ozone, just like UV-C air purifiers. Without such a coating, PCO air purifiers are not ozone-free. And even with them, they may be ineffective and produce toxic byproducts.
Here are the types of air purifier technology that do not produce any ozone.
If you have one of the air purifiers that produces ozone, there are a few steps you can take to limit the harm that it may do.
Given their limited effectiveness and potential hazards, searching for an ozone-free air purifier whenever possible is the best option for you and your family.
Ozone has always offered powerful processing and a user-friendly interface, allowing it to appeal to both experienced engineers and mastering newbies. With the release of Ozone 9, iZotope keeps that pattern going. It adds three new powerful, yet easy-to-use modules that accomplish complex mastering tasks simply, and features a new and improved Master Assistant, which analyzes your audio and suggests settings.
Ozone comes in Advanced, Standard and Elements versions. When discussing new features in this review, I’ll indicate which are included in the various versions. I did my testing in Ozone Advanced 9.0.2.
As with previous versions, you can run Ozone either as a standalone application or as a plug-in, which iZotope refers to as the Mothership. What’s more, in Ozone 9 Advanced, the assorted modules from the program are available as individual component plug-ins in your DAW, which can be handy for both mastering and mixing.
You can load up to 16 audio files in the standalone version. In addition to applying your processing chain to each one, you can trim the beginning and end of the audio file and add fades. There’s no way to zoom in on the beginning or end to get a close-up look at what you’re trimming, however. Though not imperative, a zoom control would be helpful. Playback is limited to one audio file at a time, so you can’t listen for spacing between songs from Ozone’s GUI.
The Master Assistant (Advanced, Standard, Elements) was added in Ozone 8, and it has been improved in Ozone 9. The basic idea is that it analyzes your music and then, employing its artificial intelligence, figures out a setting for you to use as a starting point.
In Ozone 8, when you clicked on the Master Assistant, it took you to a page entitled, “What are you going for?” which allowed you to choose between Streaming, CD and Reference for calculating your target output level. Reference was based on a reference track that you could upload and Ozone 8 would analyze.
In Ozone 9, your choices have been expanded pretty significantly. Now there are three categories of user options presented on the “What are you going for?” page, and your choices will determine the behavior of the Master Assistant.
First, you can choose Modern or Vintage in the Modules category. Because Ozone has both modern and vintage versions of most of its processors, you can choose which ones the Mastering Assistant will use.
Next, you have two choices to make in the Loudness and EQ section: Manual or Reference. The former lets you choose between three output target levels: Low (–14 LUFS), Medium (–12 LUFS) and High (–11 LUFS). Reference will use the level of a song or other audio file you upload as guidance.
The third category is Destination, where you can pick Streaming or CD, and Ozone will automatically set the correct amount of headroom. Once you’ve made your selections, hit the Next button, then hit Play so that Ozone can do its analysis.
As the music plays, you see an onscreen checklist of actions starting with Analyzing Audio and Analyzing Dynamic Range, Setting Maximizer threshold and more. All told, the list has seven items that check off in real-time as the Assistant finishes with them. The whole process takes maybe 10 seconds, and you’ll hear the effects of the processing as it gets near the end of the list.
Then you can choose to accept it, or you can change the previous settings and re-run the Assistant. There’s no point in re-running it if you don’t change the settings because the results will be virtually the same every time, given the same song and same settings.
The Master Assistant was quite a useful feature in Ozone 8; in Ozone 9 its expanded user options make the results more customized. The module choices and settings that it comes up with are always usable and often get you most of the way there. Most likely, you’ll still want to do some tweaking to match the specific attributes of your project.
If all you want is a finished-sounding result for sending out a demo, you’ll probably be fine just using the modules and settings provided by the Assistant. Often, if I’m in that situation, I’ll put the Ozone 9 plug-in on my master bus, and I’ll end up with a polished result with correct levels right away.
One of the completely new modules in Ozone 9 is called Master Rebalance (Advanced only). It can take a mixed master and adjust either the vocal, drums or bass levels up or down. It can only change one level at a time.
The GUI for the Master Rebalance module is simplicity itself. First, you click on a Focus instrument, either Drums, Bass or Vocals. Then move the Gain slider (±8 dB) to get it to the level that you want to hear the results in real-time. You also get a frequency display that shows the focus in blue in the foreground and the remaining signal in gray in the background. It’s useful as a visual confirmation of what you’re doing, but you really just need your ears.
Master Rebalance is designed for those situations where you have a project to master and there’s an imbalance on a song, but it’s not feasible to have the mix recalled and adjusted by the mix engineer. In the past, when mastering engineers faced such a situation, it frequently required some serious processing gymnastics and often entailed a compromise because the fix could cause problems with other aspects of the mixed audio.
iZotope has a similar feature in RX7 called Music Rebalance, which allows you to simultaneously adjust four different source types (Bass, Percussion, Vocals and “Other,” which is the remaining signal after the first three sources). Although the RX version has more range and parameter control—it also has Sensitivity sliders for each source type—I found the version in Ozone 9 to be easier to use, mainly because in RX you have to use Preview mode to hear the results, and you get a reduced-quality preview some of the time.
With Ozone’s Master Rebalance, it’s almost as if you’re still mixing. You move a fader, and the level of the source type you selected goes up and down in real-time, seamlessly. I tested it out both on my Mac Pro and on my much slower MacBook Pro, and performance and smooth playback of the feature was the same.
I’ve now tried it out on quite a few different recordings, and I’m really impressed. It is particularly useful on vocals or drums, but the bass setting works pretty well, too. I didn’t hear any degradation of the signal, even when employing extreme boosts or cuts. The algorithms are quite amazing.
I did notice that when I significantly boosted the vocal level, it also pushed up a lead guitar solo that was panned to the center. But overall, Master Rebalance could be a timesaver for experienced mastering engineers and a miracle worker for those who don’t have the experience to address imbalances in a stereo file.
FOCUSING ON THE BOTTOM
Another addition is the Low End Focus module (Advanced only). It’s designed to make the bottom end of a song more or less punchy and to reduce muddiness. It exclusively processes a user-adjustable low-end frequency range, with a default range of 20 to 250 Hz.
You get two sliders, one labeled Contrast and the other Gain. Contrast can be set to negative or positive values. The former smooths out low-end transients and the latter adds punch. Gain is a makeup gain to compensate for frequencies that are reduced by negative Contrast settings.
You can also choose between two operating modes: Punchy or Smooth. As you might expect, Punchy is designed to be more aggressive and Smooth more subtle.
A Listen button solos the frequency area being processed, which can help you choose the range and adjust the parameters. One of the many notable aspects of Ozone is that, in most of its modules, you have the option to solo just the frequency area or effect parameter you’re working on.
To get a sense of the capabilities of Low End Focus, I recommend that you start by stepping through the included presets, which have names like Clean and Punchy, Center Focus, More Kick, and so forth. They’ll show you right away what the module is capable of.
I would imagine that many experienced mastering engineers will prefer to make their own adjustments to the low frequencies using EQ and dynamics processing, but for everyone else, Low End Focus is an excellent addition for enhancing what’s going on at the bottom end of the audio.
TWO ON A MATCH
Previous versions of Ozone included a Match EQ function that you could access from inside the Equalizer module, but in version 9, iZotope has added a dedicated Match EQ module (Advanced and Standard). It’s designed to let you quickly capture a frequency spectrum from a reference track of your choice, and then impose that onto your audio, to a greater or lesser degree.
It’s simple to use; you just import a reference file and learn its target spectrum, which only takes a few seconds after you press the Capture button. Then you capture the spectrum for your song, and Ozone automatically replaces some or all of it with the reference. You can use the Amount and Smoothing sliders to increase or decrease the percentage of the reference frequency that gets imposed on your audio.
It’s easier to apply than it was in previous versions and works well for what it is, but it’s not a panacea. Imposing the frequency profile from an amazing-sounding song doesn’t mean your song will then sound just like it. To me, it’s an effect that sometimes can be useful, and I’m certainly happy that iZotope has improved its friendliness by separating it into its own module.
CHECK YOUR SPECTRUM
Another useful addition in Ozone 9 is the inclusion of Tonal Balance Control 2 (Advanced only), a new version of the plug-in whose first version was released along with Ozone 8. You can open it in the Ozone module chain using the Plug-In module, which lets you insert outside plug-ins.
It’s designed to let you compare the frequency balance of your audio to that of a reference track or one of the preset categories iZotope has included. There’s no processing involved. It’s just a way to check if the energy of your song in the Low, Low-Mid, High-Mid and High-Frequency categories is within a normal range for a particular musical style. It’s also beneficial at the end of the master bus when you’re mixing.
The first version only had three preset categories—Bass Heavy, Modern and Orchestral—which were useful but lacking in specificity. In Tonal Balance 2, you can choose from 12 genre-related categories, which is a significant improvement. If you can’t find an exact genre match for your song, you can find something close.
MORE FOR THE MONEY
Users of Ozone Standard who upgrade to version 9 will be pleased to discover that iZotope has added three modules that were previously only in Ozone Advanced. These include Vintage EQ, Vintage Limiter and Vintage Tape. All three are quality effects that offer more “analog”-sounding processing than their modern counterparts in the Ozone module collection.
With those three Vintage plug-ins added, iZotope upped the maximum number of processors in the Ozone 9 Standard module chain to 12, so you have the capability to insert one of each module type.
Another notable addition for all three Ozone versions is a resizable GUI. Just drag the right corner to make it larger. You can even fill up the whole screen with it if you want. According to iZotope, Ozone 9 offers faster performance than before. I can’t say I noticed that, but Ozone has always operated very smoothly. Also new in all the versions is support for Native Instruments NKS, allowing it to run inside an environment that supports that format.
The latest incarnation of Ozone offers plenty of impressive new features, none more so than Master Rebalance, which makes you scratch your head in wonder and say, “How did they do this?” I also was quite impressed with the revisions of the Master Assistant and Tonal Balance Control.
All three Ozone versions, but particularly Advanced and Standard, have been improved significantly and are well worth an upgrade or an outright purchase. If you can spring for it, go with the Advanced version, as it offers the most comprehensive processing options.
PRODUCT: Ozone 9 (Advanced, Standard and Elements)
PRICE: Advanced $399; Standard $199; Elements $99
PROS: Processor collection more comprehensive than ever; Music Rebalance offers impressive and time-saving results; Master Assistant now significantly more customizable; Low End Focus module helpful for shaping bass-frequency content; Match EQ available in its own, easier-to-use module; Ozone GUI can now be significantly resized; Tonal Balance 2 offers many more genre choices; vintage modules included with Standard version; standalone or plug-in operation provides flexibility; most modules offer soloing options for frequency bands or parameter types
CONS: No way to create between-song spacing for CDs; no zoom controls for trim and fade operations