Audio Mixing with Premiere Pro

When budgets permit and project needs dictate, I will send my mixes out-of-house to one of a few regular mixers. Typically that means sending them an OMF or AAF to mix in Pro Tools. Then I get the mix and split-tracks back, drop them into my Premiere Pro timeline, and generate master files.

On the other hand, a lot of my work is cutting simple commercials and corporate presentations for in-house use or the web, and these are often less demanding  – 2 to 8 tracks of dialogue, limited sound effects, and music. It’s easy to do the mix inside of the NLE. Bear in mind that I can – and often have – done such a mix in Apple Logic Pro X or Adobe Audition, but the tools inside Premiere Pro are solid enough that I often just keep everything – mix included – inside my editing application. Let’s walk though that process.

Dealing with multiple channels on source clips

Start with your camera files or double-system audio recordings. Depending on the camera model, Premiere Pro will see these source clips as having either stereo (e.g. a Canon C100) or multi-channel mono (e.g. ARRI Alexa) channels. If you recorded a boom mic on channel 1 and a lavaliere mic on channel 2, then these will drop onto your stereo timeline either as two separate mono tracks (Alexa) – or as a single stereo track (C100), with the boom coming out of the left speaker and the lav out of the right. Which one it is will strictly depend on the device used to generate the original recordings.

First, when dual-mic recordings appear as stereo, you have to understand how Premiere Pro deals with stereo sources. Panning in Premiere Pro doesn’t “shift” the audio left, right, or center. Instead, it increases or decreases the relative volume of the left or right half of this stereo field. In our dual-mic scenario, panning the clip or track full left means that we only hear the boom coming out of the left speaker, but nothing out of the right. There are two ways to fix this – either by changing the channel configuration of the source in the browser – or by changing it after the fact in the timeline. Browser changes will not alter the configuration of clips already edited to the timeline. You can change one or more source clips from stereo to dual-mono in the browser, but you can’t make that same type of change to a clip already in your sequence.

Let’s assume that you aren’t going to make any browser changes and instead just want to work in your sequence. If your source clip is treated as dual-mono, then the boom and lav will cut over to track 1 and 2 of your sequence – and the sound will be summed in mono on the output to your speaks. However, if the clip is treated as stereo, then it will only cut over to track 1 of your sequence – and the sound will stay left and right on the output to your speakers. When it’s dual-mono, you can listen to one track versus the other, determine which mic sounds the best, and disable the clip with the other mic. Or you can blend the two using clip volume levels.

If the source clip ends up in the sequence as a stereo clip, then you will want to determine which one of the two mics you want to use for the best sound. To pick only one mic, you will need to change the clip’s audio configuration. When you do that, it’s still a stereo clip, however, both “sides” can be supplied by either one of the two source channels. So, both left and right output will either be the boom or the lav, but not both. If you want to blend both mics together, then you will need to duplicate (option-drag) the audio clip onto an adjacent timeline track, and change the audio channel configuration for both clips. One would be set to the boom for both channels and the other set to only the lav for its two channels. Then adjust clip volume for the two timeline clips.

Configuring your timeline

Like most editors, while I’m working through the stages of rough cutting on the way to an approved final copy, I will have a somewhat messy timeline. I may have multiple music cues on several tracks with only one enabled – just so I can preview alternates for the client. I will have multiple dialogue clips on a few tracks with some disabled, depending on microphone or take options. But when I’m ready to move to the finishing stage, I will duplicate that sequence to create a “final version” and clean that one up. This means getting rid of any disabled clips, collapsing my audio and video clips to the fewest number of tracks, and using Premiere’s track creation/deletion feature to delete all empty tracks – all so I can have the least amount of visual clutter. 

In other blog posts, I’ve discussed working with additional submix buses to create split-track exports; but, for most of these smaller jobs, I will only add one submix bus. (I will explain its purpose in a moment.) Once created, you will need to open the track mixer panel and route the timeline channels from the master to the submix bus and then the output of the submix bus back to the master.

Plug-ins

Premiere Pro CC comes with a nice set of audio plug-ins, which can be augmented with plenty of third-party audio effects filters. I am partial to Waves and iZotope, but these aren’t essential. However, there are several that I do use quite frequently. These three third-party filters will help improve any vocal-heavy piece.

The first two are Vocal Rider and MV2 from Waves and are designed specifically for vocal performances, like voice-overs and interviews. These can be pricey, but Waves has frequent sales, so I was able to pick these up for a fraction of their retail price. Vocal Rider is a real-time, automatic volume adjustment tool. Set the bottom and top parameters and let Vocal Rider do the rest, by automatically pushing the volume up or down on-the-fly. MV2 is similar, but it achieves this through compression on the top and bottom ends of the range. While they operate in a similar fashion, they do produce a different sound. I tend to pick MV2 for voice-overs and Vocal Rider for interviews.

We all know location audio isn’t perfect, which is where my third filter comes in. FxFactory is knows primarily for video plug-ins, but their partnership with Crumplepop has added a nice set of audio filters to their catalog. I find AudioDenoise to be quite helpful and fast in fixing annoying location sounds, like background air conditioning noise. It’s real-time and good-sounding, but like all audio noise reduction, you have to be careful not to overdo it, or everything will sound like it’s underwater.

For my other mix needs, I’ll stick to Premiere’s built-in effects, like EQ, compressors, etc. One that’s useful for music is the stereo imager. If you have a music cue that sounds too monaural, this will let you “expand” the track’s stereo signal so that it is spread more left and right. This often helps when you want the voice-over to cut through the mix a bit better. 

My last plug-in is a broadcast limiter that is placed onto the master bus. I will adjust this tight with a hard limit for broadcast delivery, but much higher (louder allowed) for web files. Be aware that Premiere’s plug-in architecture allows you to have the filter take affect either pre or post-fader. In the case of the master bus, this will also affect the VU display. In other words, if you place a limiter post-fader, then the result will be heard, but not visible through the levels displayed on the VU meters.

Mixing

I have used different mixing strategies over the years with Premiere Pro. I like using the write function of the track mixer to write fader automation. However, I have lately stopped using it – instead going back to manual keyframes within the clips. The reason is probably that my projects tend to get revised often in ways that change timing. Since track automation is based on absolute timeline position, keyframes don’t move when a clip is shifted, like they would when clip-based volume keyframes are used.

Likewise, Adobe has recently added Audition’s ducking for music to Premiere Pro. This uses Adobe’s Sensei artificial intelligence. Unfortunately I don’t find to be “intelligent” enough. Although sometimes it can provide a starting point. For me, it’s simply too coarse and doesn’t intelligently adjust for areas within a music clip that swell or change volume internally. Therefore, I stick with minor manual adjustments to compensate for music changes and to make the vocal parts easy to understand in the mix. Then I will use the track mixer to set overall levels for each track to get the right balance of voice, sound effects, and music.

Once I have a decent balance to my ears, I will temporarily drop the TC Electronic (included with Premiere Pro) Radar loudness plug-in to make sure my mix is CALM-compliant. This is where the submix bus comes in. If I like the overall balance, but I need to bring everything down, it’s an easy matter to simply lower the submix level and remeasure.

Likewise, it’s customary to deliver web versions with louder volume levels than the broadcast mix. Again the submix bus will help, because you cannot raise the volume on the master – only lower it. If you simply want to raise the overall volume of the broadcast mix for web delivery, simply raise the submix fader. Note that when I say louder, I’m NOT talking about slamming the VUs all the way to the top. Typically, a mix that hits -6 is plenty loud for the web. So, for web delivery, I will set a hard limit at -6, but adjust the mix for an average of about -10.

Hopefully this short explanation has provided some insight into mixing within Premiere Pro and will help you make sure that your next project sounds great.

©2018 Oliver Peters

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