Published: August 10, 2021 | Last Updated: September 17, 2024
A crossfade is when the audio between two shots gradually increases or decreases over a brief period of time while overlapping. This creates a smooth transition, and when done properly, cuts appear unnoticeable.
There are two primary methods for creating crossfades: manually using keyframes or using transitions pre-built into Premiere.
This article will explain the differences between Premiere’s three pre-built crossfade transitions: constant gain, constant power, and exponential fade.
You can find these transitions under the Effects > Audio Transitions > Crossfade folder in the Project Panel.
What is Constant Gain?
According to Adobe’s website, “The Constant Gain crossfade changes audio at a constant rate in and out as it transitions between clips. This crossfade can sometimes sound abrupt.”
Let’s look at a visual to help us understand what this means. In the photo below, we have two clips with keyframes. The keyframes are set from infinity to 15db over the course of four frames. As you can see, both keyframe patterns constantly move in the opposite direction.
This can create a jarring transition between clips. This transition isn’t as smooth as Constant Power, which we will explore next.
What is Constant Power?
Adobe says, “The Constant power crossfade creates a smooth, gradual transition, analogous to the dissolve transition between video clips. This crossfade decreases audio for the first clip slowly and then quickly toward the end of the transition. For the second clip, this crossfade increases audio quickly at first and then more slowly toward the end of the transition.“
The photo below shows how this transition works. The keyframes on the first clip gradually decrease over several frames, while the keyframes on the second clip gradually increase the gain.
In my opinion, this is the best audio crossfade to use – especially for continuity editing. The gradual shift in gain between clips gives you the smoothest-sounding transition. Nothing dramatic changes throughout the transition, so it appears more invisible.
This is best used for projects that involve a lot of dialogue from the subject. You can cut parts of the video out without dramatically changing the audio.
What is Exponential Fade?
According to Adobe, “Exponential Fade fades out the first clip over a smooth logarithmic curve while fading up the second clip, also over a smooth logarithmic curve.“
What does this translate to in comparison to the Constant Power transition? Let’s look at a visual.
In the photo above, you can see similar keyframes used as in the Constant Power photo. Instead, the points shift in a curved line rather than a straight line. This effect accomplishes the same thing; however, the velocity of the gain changes with the shape of the line.
This transition would be used where you would want a dramatic change in audio, such as music or a change in scenes. I would not recommend using this effect for dialogue-heavy content, as the Constant Power transition sounds more natural.
Conclusion
All of these transitions have their uses in the right context. As I mentioned, I believe the Constant Power transition is the best to use because of the gradual shift in gain between clips.
You may want to experiment with all of these transitions to see what works best for your style of editing.
Up Next: How to fade in and fade out audio in Premiere Pro (including J-cuts and L-cuts).
