best iZotope RX2 workflow for a film

Question

Just completed my first narrative feature film in FCP 7. The scratch tracks have been replaced with the double-system audio, and prepped to be exported as stems if needed.

I have iZotope RX2, but not sure what the best workflow is when dealing with thousands of individual sound clips. The narrative audio tracks are of most importance to me right now, but welcome any suggestions.

Also, what is the best order when working in RX2 from top to bottom (i.e., first restore a clip and then remove the hum)? Once done, finally, what is the best way of sending the cleaned audio clip or tracks back to FCP or a DAW?

The final mix and output for festivals will be stereo, but would like to remain cognizant here on out for a 5.1 mix down the road.

Thanks for any help you can share!

Tom Have the latest MBP, FCP 7, RX2, and Soundtrack Pro (yes embarrassed to say on a forum like this, but it's all I can afford right now).

Answer 1

I will second Ryan in his assertion that post-processing is saved for later. Anything you can fix with an edit is better served with that edit than with noise reduction. It doesn't matter how good the algorithms and processors are, noise-reduction will affect the parts you want to keep as well. Experience helps you figure out when you're reaching that point of diminishing returns. It also helps to know what is going ot be happening fx/music-wise in a given scene, because there may be opportunities for freqeuncy masking that make noise reduction a superfluous endeavor. That all being said I'll give you the run-down of how I use RX2. I haven't used Soundtrack Pro, but there should be some corollaries to how I use things in Pro Tools.

After my edits are done, I duplicate the playlist on every track that needs noise reduction. I try to keep clips grouped together by their source. So, a particular character's dialog, shot on the same day, in one location, with the same mic will be on the same track...or at least a group of tracks next to each other. My goal is to do as little processing as possible, so I start with the most egregious offenders. This is usually hum and steady state noise. I'll start with Denoiser (audiosuite) in Pro Tools to get rid of noise beds, setting the plug-in to process by clip, rather than as an entire selection. Denoiser will frequently take care of a lot of the hum as well (if there is any), so that's one less process. I'll work my way through the audio files, again...only the ones that need it, and process them directly on the timeline. When the files are processed, new clips are created in their place on my newer "duplicate" playlist. If I don't like something that's happened, it's easy to temporarily switch playlists and copy the original file back into my working playlist.

If I find that there is still some steady state noise that needs to be dealt with, I'll touch it again. You're better off using 2 or three passes with mild settings than 1 that's a massive hammer. I do all of this in Pro Tools, because there's not a lot of advantage to doing these "gross" adjustments in stand-alone. Once I'm done with this, I'll make a list of clips that need additional fine tuning to deal with momentary noise issues (mouth noise, car horns, clunky feet, etc.). If any of those files haven't received any processing so far, I'll duplicate the file via "Consolidate Selection." That way, I preserve the original file in case I need to go back to the drawing board. Once I've got my list and am confident that all of the files are safely duplicated (either through the Audio suite processing, or bit-for-bit copying), I'll close out of Pro Tools.

I'll then load up RX2 as stand alone and navigate to the "Audio Files" folder for my project. Using my list, I'll do any necessary spectral repairs directly to the files in that folder. Because I am working on the files that are in my timeline, and haven't changed any file names, all of the retouched clips will be perfectly in place when I re-open Pro Tools. Note that I haven't done any processing to my original audio files, everything on my list should be those previously mentioned duplicates.

After that, I'm usually ready to start mixing. Your final mix is what would go back to your visual edit timeline.

Answer 2

Hi Tom,

RX is an extremely powerful tool especially keeping in mind its relative cost to other noise reducing plug-ins/software out there. I use RX2 almost daily and it is generally a tool used for very specific needs, it is rarely used broadly across all tracks. Generally, once a film is finished, an exported OMF/AAF along with ALL production audio (included wild recordings, alternate takes, room tone, etc) is given to the Dialogue Editor. A large part of the clean up that happens in a movie is from the meticulous and time consuming job of the Dial Editor. By using filler room-tone, alternate/wild takes, etc. you can clean up quite a bit of the "dirty" production audio. After the editor has tried everything to fix it, you then look into either post-processing (i.e. RX2 or Cedar One (if you have the $)) or ADR. Cedar One (or WAVES DNS) is used primarily as noise suppression. Its uses a very complex multi-band compression algorithm which is fully automatable and adjustable. It is very different that RX2's noise suppression which uses a sampling of the noise signal and inverts that into the original audio to cancel out the noise in the signal (hence the artifacts you get when you "over" apply this technique). The other aspects of RX2, i.e spectral repair, EQ, etc., are used as "fine" tools for stubborn sounds, i.e mic pops, cloth movements, background sounds, etc. It is quite helpful in removing small sounds, but again it is a fine tool like an Exacto knife. It is generally a combination of these tools that help to clean up production audio, but first and foremost, all attempts should be made to clean them up in the sound edit before jumping into post-processing.

Finally, when I use RX2, I like to use it in standalone mode. I have many issues using in Pro Tools either as AudioSuite or instantiated. I export the clip in question into a folder called CLEAN, open in RX2, do whatever processing is required, export as the exact same name but with CLEAN added to the end of the filename, import back into the session and replace the old clip. Others might have better ways, but this has always worked for me and I have a running tally of clips that have been processed.

Not sure if this helped, but thought I would chime in. Good luck

Best, Ryan

Answer 3

Hi Tom.

I have been facing exactly the same doubts recently since I got RX2 and am using it in several "interviewing documentaries" and other sound for video jobs. I am still starting to learn RX2, and for sure we shall exchange our experiences here, but in the meantime, the only thing I've found regarding this subject is the "manual" released at iZotope's website. Probably you have it already but anyway it's here. http://izotope.fileburst.com/guides/iZotope_RX_Restoration_Guide_v_1.pdf

All the best for you, Tom.

Answer 4

I prefer to use RX2 in standalone, but often at work I need to just use it as an audio suite to save time. I have a window configuration set up to pull up various RX2 audio suite plugs.

Answer 5

Man, this was extremely helpful; thanks all for taking the time to be so detailed and forthcoming!

Tom

Answer 6

I normally use RX2 as an audiosuite plugin, and I try only to use it when necessary. I will normally denoise a clip, IF it is too noisy, and I may also remove hum IF there is any hum worth mentioning. I will also use spectral repair, if there is a specific noise, I want to get rid of.

In the end I would rather have a final sound which is a bit too noisy than a sterile, clean and dead piece of audio, with audible artifacts.

To my experience it is always better to use audio levels, EQ'ing and reverb to make the dialogue track even, and you may also want to have some extra "clean noise" for masking the edits. if the overall sound then is too noisy, you should try noise reduction like RX2.

Sometimes a bit of noise helps the film!

• Morten