Mastering Audio Using Dynamic Tonal Processing in iZotope Ozone 9

Learn how to add sheen and shape your final mixes with iZotope Ozone's dynamic tonal processing capabilities.  

Ozone is iZotope’s complete mastering application/plug-in, providing all the various tools required for the final stage of audio production. 

Fig 1

Of course the two primary processors in mastering are EQ and compression, but sometimes static EQ settings or fixed compression values may not work perfectly throughout the entire song—as the arrangement changes, slightly different settings may be needed for optimal results. 

There are two ways to approach this—DAW automtion, or dynamic tonal processing. Ozone includes two modules that offer the latter—the Dynamics module can operate as a multiband compressor, and the Dynamic EQ module can offer a more surgical approach to dynamic tonal processing.

Fig 2

Multiband Compression

A multiband compressor is made up of several independent compressors, each applying compression within a different frequency range. 

Fig 3

This offers the benefit of having compression that will react separately to level changes in specific frequency ranges, rather than compression that reacts to level changes anywhere in the frequency spectrum. This can have both corrective and creative applications.

Multiband Compression As Dynamic EQ

In mastering it’s common to apply a little subtle overall EQ to the mix, often to add a little clarity to the upper mids and treble, to add some subtle heft to the low bass, and possibly to reduce any muddiness in the upper bass/lower midrange. But as the song progresses, the relative balance at different frequencies varies. 

With Ozone’s Dynamics module set in full (4-band) multiband mode, the crossovers can be set to divide the frequency range up into appropriate ranges for something like the above tonal tweak.

Fig 4

Dividing up the frequency spectrum and compressing each band individually will result in tonal changes to the mix, but the tonal changes will be dynamic rather than static, following overall level changes in the different bands. This can provide a more subtly changing overall EQ than similar static EQ settings—different settings can be made in the different bands, dialing up exactly the amount of effect desired.

Fig 5

Audio example 1 Four bars with no processing; four bars with multiband compression

Ozone’s Dynamic EQ

Ozone’s Dynamic EQ module works a little differently, and might be a better choice for certain, more specific tasks. 

Fig 6

A Dynamic EQ can either reduce or increase level in each band, whenever the audio in that frequency range crosses a threshold—the gain setting for that EQ band will determine the maximum amount of gain change when the threshold is crossed.

The Dynamic EQ is better suited for a specific level-dependent EQ tweak to audio in a particular frequency range—a good example might be a snare with a narrow peak that needs to be tamed. Static EQ might muffle the overall mix undesirably, and a multiband compressor would likely affect too wide a frequency band.

Ozone’s Dynamic EQ should be able to handle this. You’d narrow in on the specific problem frequency, and dial up a threshold and gain (cut) setting that tames the snare on every hit, but leaves the mix alone inbetween.

Fig 7

Audio example 2 Four bars with no processing; four bars with Dynamic EQ


So Ozone’s multiband Dynamics module and dedicated Dynamic EQ module each provide different approaches to dynamically controlling tonal variations when mastering, from subtle overall tonal adjustments to more specific problem-solving tweaks. Both tools can provide very useful processing for any mastering session.

Learn more about mastering with iZotope Ozone:


Joe is a musician, engineer, and producer in NYC. Over the years, as a small studio operator and freelance engineer, he's made recordings of all types from music & album production to v/o & post. He's also taught all aspects of recording and music technology at several NY audio schools, and has been writing articles for Recording magaz... Read More


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