Using Premire Pro for Audio Splits and Stems
Let’s talk about audio splits and stems and what we can do with them on Premiere Pro. Audio stems are a collection of audio sources mixed together. They are audio files but the significance of calling them stems is that they collectively make sense for the project. They are essential for transporting files and basically they make an engineers life easier. Audio splits are a separation of the final mix into smaller more discrete audio elements. These stems come in handy when you want to replace some elements like dialogue in a project without having to go back into the original audio project and mess around with it to get what you want. To make it easy, it is best if you have 6 mono tracks (3 stereo stem tracks) for left and right sound effects, dialogue and music. When it comes to 5.1 surround mix, sports or comedy shows you will end up with a lot more tracks and other variations. For example, in comedy shows the laugh track is isolated as a stem. So depending on the case, you may end up with with a few DME tracks or a single M&E track in stereo.
If you do work in entertainment programming, short films, commercials or corporate videos, then this should be common practice. If you do it while you are in the works of a specific project, then later down the line it WILL make your life easier. Although it is possible to go back to your files and do it later, it just saves time (time = money, people!).
So now it’s time to set up your new Premiere Pro sequence. For generating a multichannel master file with isolated DME stems in FCP X, we use the Roles function. In order to do this you need to ensure that the proper Roles is assigned from the start of your project. If you do this for the sound effects, music and dialogue Roles, then the stems will self-sort when you export them. It all comes down to how you route a Role to the channel that it corresponds to.
When we look at audio editing and mixing, Premiere Pro CC’s is also a good tool to use and the process is pretty easy. Just like I mentioned earlier though, you have to set up the proper sequence designed for the type of audio work you are working with. Correspondence is MAJOR KEY (thanks Dj Khaled). And just like I mentioned before, doing it right from the beginning will save you a headache and a trip to the quick mart to pick up some eye drops and a coffee.
Okay, so the first thing you want to do is create a custom preset. Presets are designed with a certain number of tracks routed to a stereo master output and thus you will have a 2-channel file when you export. You’re gonna want to change the track configuration to multi-channel and then set your number of output channels. Next, you’re gonna want to add the number of tracks you need and assign the regular tracks as “standard” or “stereo submix” for the submix tracks. The more complex the project, the more regular tracks it contains – and of course this all depends on the type of work you are doing with dialogue overlapping, sound effects or music on the timeline. Some sound engineers like to have what they call “zones” for the different types of audio. For this you would just have a certain amount of tracks for the dialogue, another amount for the music, and another for the sound effects – depending on the length of your timeline. To make for easy recognition and organization, it’s smart to rename your submixes according to what they contain. For example DLG for dialogue, or SE for sound effects. One cool feature about Premiere Pro is the ability to mix audio in several different places. You can do it in the audio track mixer or the clip mixer. To work with the audio track mixer, go to it and assign the routing and channel output (this can also be assigned in the sequence preset panel). For each of the regular tracks, it would be a good idea to set the pulldown for routing to the corresponding submix track, this way all of the submix tracks are routed to the Master Output.
Lastly, you’re going to want to assign the proper channel routing. This is so the sequence preset you created will contain the full mix in the first and second master channels. To do this you need to export a 2-channel file as either a review copy or a master file (only the first 2 output channels are used by default, which means these will always get the mix without you having to do anything). Next you’re going to want to enable stereo monitoring for the stereo stems. Since channels 1 and 2 are the default, you’re going to need to make some changes in order for this to happen. To enable this, you are going to need to assign the channel output in the following format: Dialogue (Submix 1) to 1-2 and 3-4, Sound Effects (Submix 2) to 1-2 and 5-6, and Music (submix 3) to 1-2 and 7-8. The reasoning behind this is that everything is going to go to both the full mix and the the isolated stereo channel for each of the audio components.
Okay, so now that the hard part is over, it’s time to edit the custom timeline. For this you simply edit any of the dialogue clips to track one, sound effects to track 2, and music to track 3. If you are working on a more complex project, then what you would work with are the “zones” I referred to earlier. For example, if 1-8 are routed to the dialogue submix track, then all you would do is edit the dialogue clips to tracks 1-8. And the same goes for the others.
Now it’s time for export. This needs to be done correctly or else all of your hard work goes to waste. To do this there are a few good choices: a QuickTime ProRes files or the MXF OP1a choices. In the export settings panel there is an audio tab, you’re gonna want to change the pulldown channel selection from stereo to 8 channels. With this you’re gonna have your timeline output channels exported as a separate mono track in the file. Now you have everything in one single, neat file, you have the final image and mix in one neat file as well as your isolated stems that can make easy changes later on. If you are a little paranoid like I am and you want to future-proof your project, you’re gonna want to save and export some extra versions with and without titles.
Let’s suppose the day for you to reuse the file has arrived. You’re going to want to import this file back into Premiere Pro. Since the channel structure is going to be read as 8 mono channels, you’re going to need to modify the file simply by using the Modify-Audio Channels contextual menu and right-click the clip. Simply change the clip channel format from Mono to Stereo. This is going to change the 8 mono channels into 4 left stereo channels and 4 right stereo channels.
If you’ve made it this far, congratulations. If this helped, thank me later. Looking forward to next time, Chris.
Photos courtesy of: Digital Films