iZotope RX 3 Reviewed

Barry Cleveland reviews iZotope RX 3.
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iZotope RX has been the noise-reduction and audio-restoration software of choice for many professional recording, mastering, and audio-post engineers for years now, as well as for many semi-pros and consumers. This third version makes RX even more alluring by offering a major refresh of the already excellent standalone user interface, significant upgrades and new features, and increased speed and reduced CPU loading thanks to more efficient use of multi-core computer processors. RX 3 comes in two flavors: the basic RX 3 package ($349 retail/$299 street) and the fully featured RX 3 Advanced ($1,199 retail/$1,099 street).

Both packages include the standalone application and five core modules that function within it—Denoise, Declick & Decrackle, Remove Hum, Declip, and Spectral Repair—along with plug-in versions of the modules that work within any DAW or other host that supports them. The Advanced package also gets you the amazing new Dialogue Denoiser and Dereverb modules and plug-ins, the fantastic Deconstruct and Time & Pitch modules, the superb Insight metering suite plug-in (a $499 value), and numerous other, um, advanced features and capabilities. (Visit izotope.com for a detailed comparison of the two products.)

Two other great new features introduced in RX 3 are Tabs (which allows you to have up to 16 audio files open at the same time and choose between them by clicking) and the RX Document file format (which embeds the processed audio’s Undo history directly into the file along with the audio, so that it automatically reappears whenever the file is opened in RX 3). Additional modules include Gain (silence to +60dB of gain, Normalize to -12/-6/0dBFS, and Fade in/out), Channel Operations (which includes the new Extract Center tool), Resample (pro sample-rate conversion), Dither (64-bit SRC and MBIT+), Plug-in (for utilizing third-party plug-ins), and a simple but highly effective Equalizer. Batch processing is also a nice touch.

While the plug-in versions of the various modules are useful in a variety of situations, it is the standalone application, with its brilliantly designed user interface, that fully unlocks RX 3’s enhanced restorative capabilities and streamlines workflow. At its heart is a Waveform/Spectrogram Display, which presents spectral or frequency information in addition to conventional waveforms, and lets you adjust the balance of the two via an ingenious Transparency Slider. Audio may be viewed and selected within either display using various tools (lasso, brush, magic wand, etc.), making it possible to edit and process audio at any resolution— from extremely detailed to entire files. And once you have processed the audio, there’s a Compare function that lets you toggle between the original and the processed version or versions, until you get the optimal result. For example, I used Declip to repair the digital clipping on stereo audio recorded by a video camera, then did a second pass also using the Equalizer to filter out all frequencies below 50Hz, resulting in three choices in the Undo window: Initial State, Declip: Settings 1, and Equalizer: Settings 1. I liked the third version, so that’s the one I saved as a new AIFF file.

My next test involved using Denoise to remove nearly all the hiss from digital backups of some 30-year-old reel-to-reel analog tape recordings without wreaking havoc on the high frequencies, then using Spectral Repair to fix a few tape dropouts on one of them by synthesizing new audio (this capability is truly mind blowing) to fill in the holes. I even tried using the Azimuth adjustment function within the Channel Operations module to compensate for what sounded like a phase issue arising from head misalignment, but it had no effect, so I suspect that wasn’t actually the problem.

As its name suggests, Dereverb is designed to reduce or eliminate ambient reverberation (say, you recorded in an echo-y garage and want to pretend you didn’t), but it can also work its magic on artificial reverberation, such as that guitar track with massive amounts of spring reverb that doesn’t sound as groovy to you now as when you recorded it. I used Dereverb on an audio book project, to match two sections of dialogue that were recorded in a stairwell (don’t ask) on two separate occasions, with varying amounts of room sound. By significantly reducing the original ambient reverberation on the recordings, and then adding a little digital reverb to both, I was able to make them sound nearly identical. Nixing excessive spring reverb on a guitar track proved less successful, though I was able to tame it considerably— but while experimenting I tried increasing the reverb (there’s even a preset called “Enhance Existing Reverb”), which yielded some very interesting results. And that brings me to my next point.

Beyond RX 3’s considerable utility as a corrective toolkit, many of its functions also enable it to be used creatively. In fact, so many RX 2 users came up with ways to utilize the correction tools for sound design purposes—especially the Spectral Selection technology—that iZotope actually developed those concepts into its powerful new Iris sample-based synth. I was only able to tap into a tiny fraction of the creative possibilities during the review period, but, for example, by using Dereverb to increase reverberance in various ways, I was able to get some fantastic and entirely unique effects, particularly when processing sounds with well-defined transients such as drums and percussion. And, I also got some very wild sounds using the Deconstruct module (which separates audio into its tonal and noise components and lets you adjust them in various ways), and other modules by selecting frequency components presented in the spectrograph and manipulating them in radical ways. Conceptually, it is a lot like Photoshop for audio.

Of course, the things I’ve mentioned here only hint at RX 3’s depth and seemingly unlimited capabilities. One could easily spend years exploring the possibilities and refining one’s techniques. At the same time, for many tasks it is remarkably easy to get good results with relatively little effort— and often the default settings and presets will get you in the ballpark, if not knock the ball out of it.

There are a number of excellent-sound restoration options out there, but in terms of comprehensiveness, power, functionality, and value, RX 3 is a formidable contender. Professionals are advised to opt for RX 3 Advanced, as it will almost certainly pay for itself quickly as a result of its excellent sound and increased workflow efficiency. But semi-pros and home recording enthusiasts will find much of the same magic in the basic package— and at $299 it is an absolute steal.

System Requirements OS X 10.6.8 or later (Mac); XP, x64, 7, 8 (Windows)
Plug-in Formats Audio Units, VST/VST 3, RTAS/ AudioSuite (Pro Tools 7.4-10), AAX (Pro Tools 11)
Kudos Extraordinary capabilities. Excellent sound. Remarkable value.
Concerns May induce option anxiety in some.