Izotope RX5 Advanced Audio Editor: Why I Upgraded

As you probably already know, I'm on a mission to learn the fine art of dialogue audio post processing. And on that mission, I've found myself using Izotope RX4 Advanced and Ozone 6 more and more often. I still use Audition as my digital audio workstation app, the hub if you will, but much of the heavy lifting is done by RX and Ozone. By heavy lifting, I mean noise reduction, compression, and loudness normalizing. But why, you may ask?

RX4 has some things that Audition doesn't have that I find important, maybe even critical to my workflow.

The first thing I'll typically do, if the particular clip needs it, is noise reduction. I like to keep it pretty light so that the audio doesn't start sounding robotic or evil which is often what happens when applied too aggressively. The dialogue denoiser is usually my go-to tool for this - only two settings to bother with and I often leave the threshold at its default and decrease the Reduction setting to about 5. If the clip is particularly noisy, I may do a second pass.


Yes, Audition has a good de-noise plugin as well but it isn't as quick and easy.

Asymmetric waveforms are the next problem I address and this is one that Audition doesn't have a solution for, at least not in its included effects.


Asymmetric waveforms have more amplitude (are bigger) above the - infinity center line than below. By itself, this is not really a problem and it sounds just fine. And it generally only occurs with male voice.

Asymmetric waveforms are really only a problem because they rob you of headroom. The peaks on one side are closer to 0dB than on the other. And this is problematic when you want to loudness normalize because you can only increase the amplitude so much before that one side is close to the 0dB limit. So you can't get all the loudness you may want. RX4s Channel Ops module has a phase rotation option that fixes this quickly and easily without messing with the quality of the audio.

Fixed Asymmetry

Once I've run the clip through the phase rotator, I'm all set to use a compressor to manage the transient peaks - the peaks that stick out well above the body of the waveform.

I could just use one of the compressors included with Audition and sometimes I do. But if I'm already in RX, I pull up the Ozone Dynamics plugin which is a very nice compressor. It has three different threshold modes (peak, envelope, and RMS) as well as a soft knee and adaptive release options. These make dialing in a fairly transparent compression easier because I don't want the dialogue to sound compressed, just more consistent.


And then I finish that off with the loudness plugin that will put that clip at the exact standard loudness level I need (usually -19LUFS for mono dialogue, -16LUFS for stereo) and also ensures that any peaks stay below -1.5dB True Peak.


Audition has a loudness normalization feature they call "Match Volume" which works nicely but it is missing the critical True Peak Limiter that is critical to prevent clipping distortion after you export your final video. That will be coming, according to Adobe, in the 2015.1 release in the next few weeks.

So why did I upgrade for a hefty $299 USD?

The loudness plugin is now much, much faster than the older one. Also, Audition still does not have a way to manage asymmetric waveforms.

Is all that really worth $299? That completely depends on you and what you need to deliver to your clients. In my case, I don't want ANY clipping distortion and I want the dialogue to sound great because I truly believe that audio is incredibly important to telling stories effectively. Possibly, audio is a little more important than visuals.

Oh, and by the way, I paid for the upgrade and Izotope has never paid me anything.