REVIEW: Izotope RX8 audio repair software

Music technology author and lecturer Stephen Bennett gets to grips with the new Izotope RX8 audio repair software…

What is it?
A new version of Izotope’s ‘Mr. Fixit’ audio restoration tool.

Whats great?
Superlative sound quality, further improvements in workflow and many useful new features. Available in different flavours to suite budget and application.

Whats not?
The full version is expensive, but you get a lot for your money.

The bottom line:
A must-have purchase or upgrade for those engaged in audio restoration, post-production and anyone fixing audio-related problems.

The verdict:
The ‘art’ of digital audio restoration has come a long way from the early versions of the DINR noise reduction software that I used with my vintage Pro Tools system. Izotope’s original RX package was a game-changer when first introduced, bringing the kind of features previously only available via expensive hardware-based processors to the desktop.

Most of the workflow in RX revolves around the Spectrogram/Waveform display which can show a visual representation of audio in various ways, the most useful being variants on Short-Time Fourier Transforms (STFT). Being able to visualize audio in this way really helps spot artifacts, thought it can also act as more ‘traditional’ waveform display. Dragging in an audio file to the RX8 window–most formats are supported—generates the display itself, while various tools are available to allow you to work on the whole file, or user-drawn selections.

RX brings several new features to the virtual table. Video calls have become an essential part of a journalist and podcaster’s life, but the software we use usually prioritises the video quality over the audio. The new Spectral Repair tool attempts to restore the audio quality that is generally lost when recorded from a videoconference. Like all of the tools in RX, the interface is pretty simple. Pressing the Learn button (many tools have an automatic system) analyses the audio and adjusts the Cutoff frequency and Smoothing amounts, while judicious use of the Amount and Vowel/Sibilant balance sliders helps you to achieve the results you desire. As with many of the processes in RX, you need to Preview the effect and then Render it to disc to make the changes permanent—shades of DINR again! Of course, you can use several tools on the same audio so you could, for example, use the Spectral de-Noise, Voice de-Reverb and (improved) de-Hum together to help clean up the audio.

Also new is the Guitar de-Noise, which worked wonders on my unshielded ‘70s Stratocaster. The Wow and Flutter tool is designed to correct problems you might find when restoring vintage tapes. I tried it on some really old cassettes and, while I wouldn’t claim the results were exactly broadcast quality, I’d be happy to use these as extras on a commercial release. There’s also a new Loudness control tool and some important changes to the Music Re-balance tool. I was pretty impressed with the latter in earlier versions of RX, as it promised to make a process possible that had long been held as impossible—i.e., make changes to the levels of vocals, Bass, Drums and the other elements of a stereo mix. Unmixing a cake, as it were. The new version hasn’t changed much visually—sliders for the above ‘instruments’ allow their respective balances to be adjusted, while a separation slider determines the ‘isolation’ of these stems. It’s now available as an ARA 2.0 plug in within DAWs that support that protocol as well, which worked fine in Logic Pro and Pro Tools. I’ve used Re-balance a lot to lift my vocals from old songs where I was less sure of my singing and have even removed elements for re-recording—though the results achieved do really depend on the source material processed.

RX8 does, in some cases, work in the same area as Steinberg’s Spectralayers, but it approaches restoration in a different way, has more features, and most are also easier to use. Don’t let the simplicity of the interface put you off though—if the automatic settings don’t get you to where you want to be, there’s enough programmability in the software to tweak to taste. There are tools available to address most of the common (and not so common!) audio issues you’ll come across and it rarely fails to produce a useable output.

Izotope continues to add in new and useful features to the RX line and, just as importantly, up the audio quality of existing tools. Which version you choose, depends on the application to which you will put the software, but the quality of processing is the same across the range. RX continues to amaze me with the way it can process audio that I’d decided unusable into workable and useful material.

Available now: Elements £98 ($129), Standard £301 ($399), Advanced £905 ($1199)