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Key Framing Audio
Hello!
I’m trying to keyframe the audio levels on some tracks within PP so that they fade in and fade out, etc. I know how to do this by clicking on the keyframe and dragging it down/up to the level I want. However, doing it this way causes it to kind of snap to a certain db level. I want it to be more precise. Is there a way I can enter a numerical value for key frames to get it exactly where I want it?
Thanks!
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4 Replies
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Just open the effects control panel, and go to the Volume control, you can click and drag or click and write a value, you can also use the arrow to expand the panel and use the slider.
Hope this helps you.
bE fREE
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Hi,
If you open up the effects panel for that clip and go into volume, you can put in the actual db level you want for each keyframe. This way you can be more precise of what level you want your audio to be at at certain parts. Good luck!
Cheers!
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Instead of key framing audio, Premiere Pro has some other very powerful tools. They are not too hard to use, but they are not exactly straightforward either. For this example I’ll be using the Dynamics Filter. It is very powerful tool and saves a lot of time and is more accurate than keyframes because it is measured in milliseconds. 1/1000 of a second, whereas keyframes are 1/24 (unless we get into sample rates themselves, but that is extremely time consuming). Moreover, dynamics processing is more accurate than keyframing. The tradeoff is it takes some learning and experimenting.
First a bit of theory (forgive my poor handwriting, and also I drew this for a friend whose compressor was slightly different but it still works):
The illustration is an example of a waveform. This one is divided into three parts: Attack, Sustain, Decay. Envelope shaping is the name for the idea that we can use dynamics processing (like the Dynamics filter) to change the shape of the waveform. There are many reasons why we want to do this, but mostly it comes down to making the audio sound pretty.
First, change the view in Premiere to Window > Audio. That way the audio mixer will be front and center. At this point, we can ignore the wave forms sitting in the editor window, because we will not be using key frames to adjust audio levels, we will be using the dynamics filter.
You have to twirl down the triangle at the very top to reveal the FX loop.
Click the triangle on the right side to reveal the effects:
And here is the Dynamics interface:
Last bit: This is a huge improvement over Final Cut Pro 7’s dynamics. Not only is the GUI nice, but there is no rendering!!
The dynamics filter is relatively complicated: there are 4 areas which do totally different things.
First, I will talk about the Compressor. Hit the checkbox. Notice also there are 5 additional settings (inside the center area). There are hundreds of compressors for sale as plug ins and they all have their own special-sauce algorithm for doing many particular things. The Dynamics Compression in Premiere is “off-the-shelf” but it is very powerful. The first setting is the Threshold.
Threshold: This tells the compressor what level to start affecting. In my illustration, I drew a couple of lines that represent the threshold. In other words, the compressor will only affect the wave form above that level.
Ratio: This is the special sauce algorithm, Generally speaking you can think of it like “turning down the threshold by x:1” where x is the number in the dial.
Attack: This is how fast the compressor will grab your audio and affect it. In my illustration, I used a “fast attack.” In my opinion, the Compressor in PP is very quick, which is fine I guess, but note the compressor in Audition has more variation. In my illustration, I drew a dashed line to represent the level while the compressor affects the wave form. The original waveform sitting in the editor has the big amplitude, but the audio signal reaching the master fader will have the new “fast attack” dashed wave form. In effect, we have “compressed the waveform” so that the difference between the highest value and the lowest value smooths the sound.
Release: This is when the compressor turns off. The compressor says “the audio is no longer in the threshold, so I will turn off after x milliseconds. Playing with this setting is key, because often if it is too quick you can get a “pumping sound” where the audio is comrpessing and releasing so fast it sounds wrong. If that happens, usually the release is too quick.
Make up: Overall a compressor turns down the volume, so you can make up the volume loss with this setting and it will result in an increase of perceived loudness. This is a good thing, a very good thing. You can read my “P” example in the illustration.
The next effect to discuss is the Expander: It is the opposite of a compressor. It will turn things up! I use this when people seem to be talking too softly. Notice the decay in the illustration. To smooth things out, adding an expander of -40 and ratio of 2.0 will increase the perceived loudness This is good because often as people talk they end up trailing off the ending of their thoughts, but maybe its good content, so you need it up.
What would I do without a limiter?! For broadcast work, I always always always put a limiter of Threshold = -12dB and a Release of 50ms. Before I do that though I dirty mix the master using the faders (not keyframes), so they hit about -12dB. There’s a great art to this and it take some practice.
I will now circle backwards and talk about the AutoGate. An audio gate means “letting stuff in.” In effect, the AutoGate says I will only allow audio in that is louder than the Threshold and if it is I will turn on as fast as the Attack. The release is the same as the compressor. The Hold is just that: stay on for this long to avoid pumping.
Finally the softclip, changes the waveform gradually and if there is a peak (distortion) it will pull back that gunk and allow a smoothing before the distortion.
Hope this helps 🙂
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Great explanation, thanks!
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