Audio Plug-ins for Editors – Part 1

Audio mixers and audio editors who spend their time at the business end of a DAW certainly have a solid understanding of audio plug-ins. But often it’s something many video editors don’t know much about. Every NLE includes a useful complement of audio filter effects (plug-ins) that can also be augmented by a wide range of third party options. So it’s worth understanding what you have at your fingertips. After all, audio is at least 50% or more of most video projects. For this and the following three posts, I’ll focus on some thoughts pertaining to what video editors should know about commonly used audio filters.

Numerous audio effects have been highlighted in previous posts. I personally use various Accusonus and iZotope effects on my work, most often for audio clean-up. That’s been very important in this past year with restricted production activity. Quite a lot of my recent edit jobs worked with source material from Zoom calls and self-recorded smartphone video – all with marginal audio quality. So clean-up tools like iZotope RX have been quite important.

Since a lot of what I do is corporate in nature, the mixes are relatively simple – usually voice and music with a minimum of sound effects. Other than some clean-up processing (noise or reverb removal and so on), my most frequently used effects are equalization and compression. These tools let me shape the mix and control levels. 

All audio plug-ins are the same. Or are they?

Audio effects typically come in two flavors. One group could be described as “digital” and is intended to process audio in a transparent fashion without adding tonal color on its own. The other group is considered “analog,” because these filters are intended to emulate the sound of certain analog processing equipment. Naturally, since these are software plug-ins, the processing is actually digital. However, analog-style emulations are designed to mimic the tonal qualities of classic outboard gear or of channel strip circuits built into analog consoles like Neve and SSL.

Tonal color is often created by how the audio is processed, such as the slope of the attack and release characteristics when the filter begins to affect the sound. In theory, you should be able to take a digital-style EQ and boost a frequency by a given amount and Q value (the width of the effect around that frequency). Then, if you apply a second instance of the EQ and cut (lower) that same frequency by the same dB and Q values, the two should cancel each other out and the signal should sound unaffected. An analog-style filter that has been designed to emulate certain models of peripheral gear will not be transparent if you try this same experience.

If you buy two competing digital audio plug-ins that have the same controls and features, then the way each alters the sound will likely be more or less the same. The only difference is the “skin,” i.e. the user interface. However, when you buy an analog audio plug-in, you are looking for certain sound characteristics found in current or vintage analog hardware. A developer could go the route of licensing the exact signal path from the original company. They can then legally display a branded UI that is skeuomorphic and looks just like the physical version that it represents. Waves has an entire repertoire of such effects. So if you want an SSL 4000-series E-type channel strip, they’ve got a software version for you.

The other development approach is to reverse-engineer the sound of that physical gear and release a plug-in that emulates the sound. It might be dead-on or it might only be reminiscent. The skeuomorphic interface is designed to look and feel like that gear. If you know the real device, then you’ll know what that plug-in can be expected to sound like. Apple Logic Pro has a wealth of effects that are emulations. If you want to use a Vox or a Marshall guitar amp filter, simply pick the one that features a similar faceplate. Nowhere does Logic actually call it a Marshall or a Vox, because Apple hasn’t licensed the exact circuits from the original manufacturer. Instead, they classify these as “inspired by” certain musical eras or genres.

Native versus third party effects

Audio plug-ins are installed using one of several protocols, including AAX, AU, and VST/VST3. This means that you can use the same effect in multiple host applications. However, DAWs and NLEs also install their own native effects that are only available within that single application. This can mean better performance versus third-party effects, which is especially true with current versions of Final Cut Pro and macOS.

One of my favorite native filters is the Logic compressor found in both Logic Pro and Final Cut Pro. It features seven compressor styles built into a single plug-in. The choices start with Platinum Digital, which is the digital (clean or transparent) version of this filter. The next six panes are different analog models, which are emulations of such popular outboard gear as Focusrite and DBX. There are two choices each for VCA, FET, and opto-electrical circuit designs.

Set the exact same adjustments in any of the compressor’s panes and the tonal color will vary slightly as you toggle through them. If you are unfamiliar with these, then check out some of the YouTube tutorials that explain the Logic compressor’s operation and which of the actual gear each of these panes is intended to emulate. I personally like the Studio VCA pane, which is based on a Focusrite Red compressor.

In Part 2, I’ll take a deeper look at two of the most common filtering functions – compression and equalization.

©2021 Oliver Peters