This review was written by Mark Harris, who works in the Absolute Music web team.
iZotope RX 3 is a high powered suite of restoration plugins. I have been working with the Advanced version of the software, which adds extra modules to the suite and extra features to some of the standard modules. The software can be used in either standalone or plugin mode although in plugin mode, some of the more detailed controls are disabled as they cannot be run in realtime.
The suite is designed to be fast, powerful and easy to use. The workflow is based around one window in which all of the tools are easily accessible.
The main section of the window contains the waveform display. Working in a graphical manner, selection tools allow you to edit your audio as if it were an image. You can fade between a waveform and a spectral display, making it very easy to make detailed, precise edits and the tools feel very natural to use. The display zooms and scrolls smoothly and the resolution is very high, allowing you to delete, trim and silence areas of the audio or make selections to process with the modules.
However, the module rack on the right of the window is where the real magic happens, so I'll start with the modules found in the standard edition...
The Denoise module takes care of background noise, hiss and other constant sounds. It analyses the audio and attempts to remove constant noises. I tested it on a track with wind noise and using the manual mode, it learned and removed it almost straight away. I just had to adjust reduction and threshold values to taste. Very impressive.
The Advanced edition also has a second mode, which is specifically trained towards cleaning up dialogue. I tested this with some in-car dialogue with a lot of background road noise. This was a bit more tricky, but it still only took a couple of minutes before the noise was significantly reduced without affecting the sound of the voices.
The Spectral Repair module works in the same manner as the Denoise module, but it specialises in non-constant sounds in a selection. I tested this module with the outdoor recording again, but this time to remove large blasts of wind. The attenuate function worked very well to reduce the level of the noise without affecting the rest of the sound. However, the replace function was the most impressive part; it analyses the audio to each side of the edit and replaces it with generated audio to match the context. It replaced the noise seamlessly.
The module can also search for patterns and harmonic noise. This works beautifully to clean the audio with minimal impact on the sound you want to keep.
The DeClip module is pretty self explanatory. From a selection, it constructs a new transient to remove the clipped artefact. I again used the outdoor recording and was pleasantly surprised by the results.
The DeClick & DeCrackle module is great for those digitising vinyl or archiving other sources. I used it on some audio I recorded that had some digital clicks in it (deliberately!). Working from a selection, it has several different algorithms for a range of different circumstances. It cleaned it up wonderfully with no artefacts.
The Remove Hum module works as a tight filter with an intelligent algorithm. There are presets for common hums and the learn function can seek out any other problems.
The Advanced edition adds the Deconstruct and DeReverb modules. Deconstruct allows you to separate tonal and noisy sounds. I tested this on some acoustic guitar recordings where I managed to separate and remove fret noise, retaining the musical notes.
The DeReverb was especially impressive. I took some dialogue recorded in a lively kitchen and it reduced the reflections, creating a tight, controlled sound.
iZotope RX 3 gives you other audio utilities such as a 6-band EQ, Gain and Phase controls, Sample rate conversion and dithering modules. The EQ is very precise and works as an analogue or linear EQ. The world class SRC sample rate converter works in 64-bit and works from 11.25kHz, all the way up to 192kHz. You can also run VST or AU plugins to give the suite a truly creative edge.
The Advanced edition provides you with a Time & Pitch module, Azimuth Alignment, and comes bundled with the Insight metering suite.
RX 3 is a truly impressive package and is perfect for broadcast or film audio and archiving work. It is also ideal for anyone who needs to clean up audio and wants to have the most detailed, accurate and intelligent algorithms at their disposal. All of the edits I performed were clean and seamless. I was very impressed at how clean the adjustments were and how fast and easy it was to get the results.
For those who just need a quick fix for things like hiss, hum, clicks, pops etc, the Standard edition is more than enough. It is incredibly powerful and is also perfect for those archiving LPs and tapes.
If you need that extra precision and a faster workflow from the adaptive algorithms, then the Advanced edition is for you. It also gives you the extra control of the DeReverb module. The Advanced edition is the choice for those in broadcast and film as it includes the Dialogue Denoiser. This module really makes editing location dialogue a breeze and saves a lot of time in the ADR suite!
RX3 really gives a new meaning to "Fix it in post!"