Review: iZotope's RX 3 Advanced
Erik Vlietinck
Issue: November 1, 2013

Review: iZotope's RX 3 Advanced

PRODUCT: iZotope RX 3 Advanced

PRICE: $1,199


- effective noise remover
- comprehensive metering tools
- time stretch & pitch change capabilities

With the number of indie movies and amateur videos on Vimeo and YouTube on the rise, the need for sound engineering is more prominent than ever before. Recording an interview on the street using state-of-the-art equipment and a soundman usually results in decent audio, although background noise can still make a recording sound bad. A one-man operation recording with prosumer gear will get even less ideal results. With iZotope RX 3 and RX 3 Advanced, audio perfection is no longer the realm of highly specialized sound engineers. While the app still has all the bells and whistles that make the pros happy, the technology has been made quite user-friendly for less-skilled enthusiasts.

RX and RX Advanced are two of the most powerful and effective sound repair applications on the market. I have reviewed RX Advanced 1 and 2, and found both to be unbeatable in terms of sheer power and capabilities. They were less user-friendly than the current new version, though.

Under the hood, the DSP used in RX 3 and RX 3 Advanced has been improved. In addition, both have a brand new interface that is much more user-friendly. In total, there numbers around 100 improved features. Many of these make it possible for even the unskilled user to quickly remove noise and artifacts from a sound recording. 

The most spectacular feature in RX 3 Advanced is Dialogue Denoiser. Other new features include Dereverb, Asymmetric Declip, Center Channel Extraction, Pitch Contour, Radius Time, and Pitch Stretching. In RX 3, as well as in RX 3 Advanced, you’ll now find multi-file capabilities, multicore processing, the ability to save edits as RX documents, multiple noise selections and phase rotation. RX 3 also has three features that previously were only available in RX Advanced: plug-in hosting, MBIT+ dithering, and SRC sample rate conversion. 

One major new feature is the ability to record audio straight into the application. Together, with the new capability to save RX 3 edits into RX documents, this enables you to use RX 3 as a full-blown sound editor. One of the advantages of recording straight into RX 3 is that you can mix a mono signal — usually you will use one microphone when recording a screencast or a movie clip in the field — into a perfect stereo channel and immediately start editing the file. 

For those of us who aren’t sound engineers, RX 3 Advanced has an incredibly effective noise remover — Dialogue Denoiser — that doesn’t require you to make decisions about method, fine-tuning or whatever else. It’s a one-click, noise-removing algorithm that does all the heavy lifting for you. It has been developed with podcasters and video producers in mind, and is specifically tuned for dialogue and voice recordings. I tried it with a recording of a street interview and the results were astonishing. 

A step up in terms of control is the RX 3 Denoise Module, which literally muffles noise. Spectral Denoiser is designed to denoise anything. This means you don’t need to make a full-bandwidth, time-based selection of noise to create a fingerprint from. You can actually select elements of the noise profile that appear in-between harmonics, using the selection tools, and learn the noise profile from that. There’s even an auto complete feature to fill in the gaps. I tried this new feature and was expecting synthetic sounding results, at best, but in reality, it turned out to be a very powerful audio repair feature. 

Pros will appreciate iZotope’s Insight, which is now included for free with RX 3. Insight provides all the metering and analysis tools you will ever need.

Declick and Decrackle, the module that allows you to remove short impulse noises like digital errors, mouth noises, cell phone interference, etc., now offers RX 3 users Declick presets. RX 3 Advanced users also get two advanced parameters: Click Widening and Frequency Skew. The latter tunes the frequency response of the click detector, while the former lets you increase the processing region around each detected click. The result is better handling of low frequency clicks and cleaner results. Sometimes an audio recording will contain clipped sound. Especially when you’re recording music, you may run into the clipping problem. When that happens, RX 3 has an enhanced declipping algorithm with the declip areas showing directly in the waveform. This makes it much easier to see to what you’re doing and how much of the signal will be corrected. RX 3 Advanced also has Asymmetrical Declipping, which further increases accuracy by allowing users to independently set signal top and bottom thresholds. 

Another major new feature is the Dereverb module, which removes resonance resulting from the room’s sound character. Sound recorded in a church will have much more reverb than when it’s recorded in a small room. However, I found that even in my small office, I experienced some reverb. The Dereverb tool let me remove that bit of reverb and gave me a much tighter sound, much more in tune with the business video I was recording. 

Often, when recording a presentation or screencast with a voiceover to be recorded afterwards, you will misjudge the timing of what you’re saying with what is happening on the screen. Instead of having to start all over, RX 3 Advanced allows you to speed up or slow down your sound. The time and pitch stretch module Radius allows you change timing — and pitch if you need it — without changing the overall sound characteristic and quality. 
Phase rotation is another tool that can turn a good audio file into a perfect one. Contrary to phase tools in other sound editors that I know, the RX 3 tool allows you to rotate freely. Rotating the phase of a signal changes its peak values but leaves everything else intact. Rotating the audio channels so they become more symmetrical, adds to the signal’s headroom. 

There are more new features and improvements, but for video and movie producers, these are the most important. If you care about the sound in your video, RX 3 Advanced is the best sound repair and cleaning application on the market. Even good products like Sony’s SpectraLayers Pro 2 can’t compete. RX 3 is faster, offers more powerful tools, and in most cases, is easier to use.

Erik Vlietinck can be reached by email at: