Every once in a while a company comes along with a product that changes the way things are done.  iZotope RX is one of these products. They have some excellent samples of its capabilities on their website:

iZotope RX website

The coolest thing about RX for me is that it brings advanced visual editing to the masses, enabling people to better see what they want in the audio, and what they don’t. Here is a good example to go along with the Car Beep example they have at the bottom of their page. For those that aren’t familiar with this type of display, it is a plot of frequency (height), time (which progresses horizontally like any other software), and volume/intensity (the brighter the orange the louder the sound.)

You can clearly see the repeating beep at around 2 kHz and with RX you are able to use multiple selection tools to select the beep (and any harmonics when using the Magic Wand selector.) Holding down Shift enables you to use different tools and keep adding to your selection until you have what you want.

Once the problem areas are selected, there are many options for dealing with the issue, the most flexible of which is Spectral Repair. This enables you to bring down or entirely remove a problem area in the spectrum and even resynthesize what you expect to hear. It is actually possible to replace entirely missing audio using the surrounding context, which is ridiculously cool, although finding an application where it works great can be a challenge. I’ve had excellent results with Attenuate (the most hammer like tool in Spectral Repair) and Partials+Noise (perhaps the most surgical of the Spectral Repair tools.)

Standard restoration process are available in RX, enabling you to remove noise, hum, crackles, and even clipping from audio. Using noise reduction has always been an art in compromising, trying to remove the most noise while leaving the most desired sound intact. The better the tools get the less compromise you need to make, and the further you can push it and get results. RX is a big step forward in many ways and really enables some amazing editing. Below is the car beep audio spectrum display for “after RX.” Please note, this  display is not a capture of the “after” sample from their website. It shows the actual results after my own processing using RX and the Partials+Noise function in Spectral Repair.

- Joshua

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