There really are no duds in the RX pile. But a few do stand out, and have been greatly improved.

For example, the de-noising processor has always been, in my opinion, one of the best available. Used intelligently and gingerly, it will reduce or eliminate all sorts of room noise or AC noise, and even works well on wind noise. The trick to getting good results is to go easy on the reduction parameter, and do as few passes as possible. It is often the case that simply reducing noise is more than sufficient, while trying to totally eliminate it may leave you with artifacts and less than perfect results. The improvement in version 3 is the ability to select multiple noise areas in one file, using the brush tools. So instead of having to pick one representative noise sample and teach the plug-in that it is the noise you want to reduce, or making multiple noise reduction passes on the same file to target different nasties, you can now select multiple noises in discontiguous areas and eliminate them all in one go.

Another good one is the de-clip module. Mitigating clipping distortion in a digital recording is one of the hardest things to do without damaging the overall sound. Simply cutting the high-end EQ will reduce the “fuzz”, but will leave the overall sound dull. And my experience with de-clipping plug-ins has been that they leave the file sounding much worse than it did with a little bit of clipping it. Frankly, the only effective way of eliminating clipping is to go through the file with a pencil tool, and manually round off all the square tops, a time-consuming task. The de-clip module in RX is one of the only ones I consider to be effective. It still requires a light touch, but the results have been more than acceptable. Version 3 automatically smoothes those clipped peaks in a manner that is usually inaudible, and will even reliably select a suitable threshold where the clip processing should kick in. It’s a good one.

The spectral repair module has also rocked the world of more than one of my clients. The ability to isolate very narrow frequencies over long durations and reduce their level, without affecting the rest of the frequencies, has bailed out many an actor. Do be aware that spectral repair is not always real time task, depending on your editor, so that plug doesn’t always work in all editors. Don’t worry, RX gives you a friendly warning and asks you to try another editor.

Did I mention that you can now save your work in a format called RX Documents, which saves a list of processes and settings performed, unlimited undos, and the original audio in one file? This is not a file for you to give to your client, but it is one to keep for yourself so if you have to go back in the future and undo it or redo it, you can do so by just pulling up one file. Brilliant.

As mentioned, all of these processors are available as individual plug-ins for use in your audio editor program. As you might expect, calling up any one of them brings up the same small window that you will see overlaid when you select a processor from the standalone application. The features, functions, and controls in the plug-ins are identical to those that come up in the standalone app.


As you might have noticed, iZotope’s RX is available in two separate versions; RX 3 and RX 3 Advanced. RX 3 is the regular version, while RX 3 Advanced has all the functions and features of the regular version, but adds many more parameter controls for more precise operation, and to accomplish tasks particular to a specific job like working with dialogue or audio forensics. Understand from the beginning that the regular version will have 95% of the functions the average producer or voice actor will need to clean up their tracks. Given the large price difference between the two versions ($350 versus $1,200 US retail), you might be better served by renting some studio time at a facility that owns the Advanced version, and has an operator who’s familiar with using it.

But if you do have the necessary resources (read: cash), the Advanced version adds a whole lot of muscle. My personal favorite is the de-reverb, which not only reduces or removes reverb processing that has been applied to an audio file, but can also simply reduce or remove room tone from a file. The results are not always perfect and depend upon what sort of reverb and how much was applied, but it’s the first plug I’ve ever used that does a credible job of removing room reverberation.

And the dialogue de-noiser does its job in real time. That’s right, it removes the common room noises, hum sounds, and other gremlins as the track is being recorded. There’s still more items in the Advanced, and it is not to be sneezed at. But it is expensive.


So what do I think of the new version of iZotope’s RX? I like it every bit as much as previous versions. iZotope has actually made some useful changes and additions to it. Opening multiple files at once, being able to scrub audio, and being able to perform phase rotation on voice tracks that have been recorded with asymmetric waveforms... these things are not eye candy. These are useful functions, and by the way they are included in the regular version of RX. It doesn’t come cheap, but if it can save your bacon on an important audition, I think it’s worth serious consideration.

Yes I know, all of the screenshots in this article include a big trial banner somewhere on the screen. Of course I’m running it in trial mode. I own a copy of RX Advanced version 1, which as I mentioned above I’ve been using for quite a while. The upgrade to version 3 is at the time of this writing about 400 bucks. That’s a fair chunk of change.

But given how much I like this product, how useful it’s been to me over the years, and quite frankly how much money I’ve made fixing other people’s audio problems with it, I figure I’ll make that money back long before version 4 comes out. So yes, I’m buying the upgrade.

iZotope’s RX (regular) is available at a US suggested retail of $349. RX Advanced is available at a US suggested retail of $1,199. Reduced upgrade prices are available on the company’s website store. For more information, visit