Audio, Reviews

iZotope RX 6 Advanced, the biggest upgrade ever

iZotope’s RX audio editor was upgraded and released last week. It repairs, restores and enhances audio and is frequently used to fix sub-par audio in post-production. With nine new features included, version 6 is the biggest RX upgrade ever.

RX 6 is now available in four versions:

  • RX Elements, a budget-friendly version of RX, featuring the Voice De-noise, De-clip, De-click, De-hum plug-ins and the standalone audio editor
  • RX 6 Standard, which includes everything in RX 6 Elements, plus additional features including De-bleed, Spectral De-ess, Mouth De-click and Spectral Repair
  • RX 6 Advanced, the premier version of RX that adds De-Wind and advanced features made possible through machine learning, like De-rustle and Dialogue Isolate — this is the version under review
  • RX Post Production Suite 2, a comprehensive post-production toolkit for everything from dialogue editing to mixing and delivering. Post Production Suite 2 includes RX 6 Advanced, Neutron Advanced, RX Loudness Control and Insight, as well as a 1-year all-access pass to Groove 3 Video Training and 50 download credits to the Pro Sound Effects Library.

New features in RX 6 include: a Composite View, MP3 export, Breath Control, De-bleed, De-ess, Mouth De-click (all of these in the Standard as well as the Advanced version), De-rustle, De-wind and Dialogue Isolate (these only in the Advanced version). I only couldn’t properly test De-rustle as I lack a lavalier mic.

De-ess is also available in Nectar 2 and I have reviewed that app when it got released.

Machine-learning and intelligent signal processing

In version 6, Standard lacks the intelligent features that are based on machine-learning. Those are available to Advanced users only. In essence, this means that you get a lot of extra features in the Standard version that are really going to help you improve and repair music as well as post-production files. However, if you are into heavy outdoors recording for video mainly, you’ll be better off buying the Advanced version. That one offers you the best chance of improving audio dramatically, even if your equipment is not top-notch.

With RX 6 Advanced you can also improve a signal more quickly, more precise and without deep audio processing knowledge in more circumstances. For example, I made a recording of my voice talking to the birds in the back garden against a considerable background noise coming from the nearby motorway.

In previous versions of RX, I had to use and tweak — often by trial and error — at least two modules to make the monologue stand out well from the noise. It was also harder to avoid the “underwater sound” effect you get when you need to apply high repair settings and which is often characteristic of FFT-based processing.

In RX 6 Advanced, I could do with one module — Dialogue Isolate, which uses a deep neural network — and very little fine-tuning.

De-wind worked in the same, almost magical way. With enough of the occasional gusts of wind to generate the low-frequency blowing sounds I needed, I can say I was surprised by the efficiency of the module. De-wind did need a bit of fine-tuning, especially when the rumbling was strong.

The Composite View is another great new feature. It allows you to create a group of open audio clips and apply your adjustments to all of the clips at once. This saves a lot of time when fixing audio problems as you’re often dealing with audio clips that have been recorded under the same circumstances.

Another new feature that improves efficiency considerably is De-bleed. It relies on a relationship existing between your active track and the Bleed Source track in order to function properly.

De-bleed is meant to reduce the leakage of one signal into another, such as when a click track fed into headphones bleeds into an open mic. Both tracks, however, must be time-aligned within a few milliseconds of each other.

If that’s a problem, RX allows you to create a silent gap in one track that you can fill using the Signal Generator. This allows you to time-align both tracks. Of course, when it’s video you’re dealing with, you can also — and faster — do this using PluralEyes.

RX 6 Standard will be available for $299 USD (reg. $399), RX 6 Advanced will be available for $799 USD (reg. $1,199).