Join Chris Meyer for an in-depth discussion in this video Audio levels, part of After Effects Apprentice 06: Type and Music.
There is a dedicated audio panel that you can use to work with your audio tracks. Whenever you are previewing audio, these meters show you how loud the audio is. For example, I will press Period on the keypad. (music playing) The general goal with audio is to be as high on these meters as possible without this very top bar blinking red. If that top bar blinks red, that means there is a chance that you are overloading or distorting the audio, and you might need to reduce its level.
Now audio has an unusual system of controlling its power. It's not like 0-100% scale. It's in a system called decibels, which is a power base scale, not a linear scale. When you have an audio track selected, you can actually change its level by dragging on these controls inside the Audio panel. I pull them down, the auto will be significantly quieter. (music playing) I could barely hear that. Or if you drag it up just a little bit, it will be significantly louder. (music playing) And you can see I was hitting these little red dots here, which means the audio was too loud.
I want to pull it down. You can go ahead and use this slider. You can control the left and right channels independently if you want to, or you can edit values numerically. Now, 0 actually means no change. Zero in audio is equivalent of 100% scale or 100% opacity. Again, I told you, audio is a little bit different to deal with. If you want to completely silence the audio track, you don't set it to 0; you actually set it to a value of -96 decibels.
That's silence in 16-bit resolution audio. But just set it back to unity, no change, we will go to 0 again. You can change these levels in the Audio panel or, in Timeline panel, select your audio track and press L-- that will also reveal audio levels with a primer you can scrub. Now you will notice that there is an animation stopwatch for audio levels; however, I highly recommend you don't keyframe audio levels.
Since it is a power-based system, the way that it fades up and fades down in between keyframes, the away After Effects interpolates audio, just sounds funky. The fades don't sound right to the ear. They rush up and they rush down. If you need to actually animate your audio levels, for example to fade an audio track in or out, instead I recommend using Effect > Audio > Stereo Mixer. Stereo Mixer now has the very common 0 to 100% you are used to from say Opacity, Scale, et cetera. You can go ahead and keyframe 0 to silence, 100% to normal, above 100 to scale up the audio, potentially distort it, back down to 0 for silence.
I reserve audio levels just to balance audio tracks against each other, make things louder, make things quieter, maybe raise the level of dialog or lower the level of music so dialog is more intelligible. But if I need to do fades, I will keyframe the Stereo Mixer effect instead. And by the way, there are indeed other audio effects that I won't be bothering to go into. A lot of these just create kind of funky little things, like Modulator creates warbling sounds, Flange & Chorus comes from a typical guitar processing sound.
I personally find that the very simple, very humble bass and treble is all I need most of the time in After Effects, maybe make a voice more intelligible by increasing its treble, maybe reducing rumble in a room from a truck outside or the air-conditioning system by reducing the bass value. But if I need to do more sophisticated audio processing, I tend to use another program like Adobe Audition, Sony Sound Forge, programs like that. Indeed, After Effects itself is not a great audio program, but what After Effects is good at is allowing you to coordinate your visuals to go along with audio.
That's what we will tackle in the next couple of movies.
The After Effects Apprentice series was created by Trish and Chris Meyer. The tutorials are designed to be used independently and as a companion to their book After Effects Apprentice.
- The core text animation recipes
- Animating text along a path
- Working with text animation presets
- Timing animation to audio
- Per-character 3D type
- Rendering with an alpha channel
- Making Photoshop type editable in After Effects
- Professional typesetting tips