The Center Channel Extractor is an incredibly powerful effect inside of Adobe Audition CC that can allow you to attenuate or minimize vocals from a track and in some cases remove them entirely.
It also has the capability to isolate vocals creating that very sought-after acapella track that people use often in remixes and mashups and things of the like.
Now this is entirely dependent, and your success in using this effect is entirely dependent on how the original track was mixed and recorded, and ultimately your best successes will be made when you have a music track where the vocals are contained in the center.
Apply the Center Channel Extractor effect
Now you have two ways that you can apply this to a track.
You can either add them to the Effects Rack, and by clicking on the fly out menu here I can go to Stereo Imagery, Center Channel Extractor...
Or you can simply go up to the Effects menu and choose Stereo Imagery, Center Channel Extractor...
And we're going to start actually with one of our default settings.
And you'll notice that we have a Preset menu.
So let's go ahead and click the down arrow here.
And in the Preset menu you'll see that I have something called Vocal Remove including some of my own customized presets.
You'll also notice there's one here called Karaoke (Drop Vocals 20 dB).
Well I'm going to start with Vocal Remove
Apply the Vocal Remove preset
which is going to use the most aggressive Center Channel attenuation.
Let's go ahead and use that.
And we'll start simply by disabling the effect, and let's play it back with all the vocals contained.
And then I'll turn on the effect so you can hear what it's doing and how it's able to remove some of that Center Channel vocal information.
Here we go.
Pretty amazing stuff.
And this is with the default preset.
Now a couple of settings that I want you to be made aware of: First and foremost as mentioned this is attenuating
Adjust the attenuation
those Center Channel vocals at approximately 40 dB.
So if you find that it's pulling out a little too much, because oftentimes you'll have things like kick drum, snare drum, bass guitar also contained in the Center Channel this is where you can adjust that attenuation amount.
And again this particular preset uses a fairly aggressive amount of attenuation, but it really gets the best results.
Customize the frequency range
Now you also have the ability to customize the Frequency Range.
So as I mentioned a lot of times you'll have bass contained in that center.
So if you choose your Start frequency at 120 Hz which is the default for this particular preset or perhaps a little bit higher that's telling you that it's pulling out frequencies between 120 Hz and in this case 20,000 Hz.
Bass frequencies and the fundamentals of most of your bass frequencies can be found in the 50, 60, 70 Hz range.
So that means that this is not affecting the bass even if it's contained in the center and if we roll this up a little bit higher to 150 or 180 Hz you'll actually preserve even more bass as we're removing those vocals.
So let's now try adjusting the Start and End frequencies here and you'll kind of see how it tailors and customizes the sound of attenuating that Center Channel information.
Okay?
And you notice that as I started to go down below around 80 Hz all of that bass started to disappear.
That's because we were pulling it out of the center.
But as I raised that starting frequency 120, 130, landing around 160 Hz the bass is still there, we're hearing the kick drum and the snare and the vocals are totally gone.
So that's vocal removal.
Discrimination settings
And one other thing that you can do if you go into the Discrimination tab here, you'll see that you have even more control over sort of changing how it's accounting for some of the bleed and the Phase Discrimination, so that you can preserve some of the things that it's pulling out.
One field or one particular parameter that I like to adjust is this one here: Phase Discrimination as well as Crossover Bleed.
Now again these will be seasoned to taste.
You have to try these out on your own files to see how they will work.
But let's take a quick listen I'll wind back again before we get to that chorus.
And let's just see what happens as we play around with Phase Discrimination.
And you'll notice that as where we started around 5° or 6° as I went lower 3.1° we actually preserved a bit more of that snare, a bit more of some of the information that was perhaps just left or right of center making this a really amazing karaoke styled track.
And that's ultimately what you want.
Apply the Acapella preset
So that's a basic tip here on Vocal Removal.
Now what about vocal isolation or preservation?
So for that we're now going to turn to the Acapella preset.
Let's go ahead and choose Acapella.
And now you can see that it leaves the Center Channel at 0, but now it's attenuated all of the Side Channels.
Now here is we're playing with that Frequency Range is going to be very important.
Because right now it's preserving everything between 115 Hz and 17,000 Hz or 17 k.
Now again in the center you might have acoustic guitars, you might have symbols, you might have a lot of brightness and other high-end elements from other instruments bleeding into the center.
So if we drop this higher Frequency Range here this is going to allow us to focus more on the vocals themselves.
Now you might get other instruments in there; that's just one of the artifacts of doing this.
If you want it completely clean and discreet you'll have to go back to the original multi-tracks.
But now listen as I start dragging those frequencies down a bit, isolating the vocals a bit more, also making them sounding perhaps a little bit more mid-rangy.
Let's take a look.
And once again I'll start in the off position and then we'll kick this in so that you can hear what it's doing.
Here we go you.
And there once again you can see that by adjusting that Crossover Bleed increasing that percentage a bit and by adjusting the Phase Discrimination by just a couple of degrees here, we can start to just further refine and isolate those Center Channel Vocals and make them stick out a bit more.
There's a little bit of bleed from some of the other instruments and things, and you can continue to use these additional settings to fine-tune those even more.
But very quickly and starting with presets the Center Channel Extractor allows you to pull out, attenuate and minimize Center Channel vocals all the while preserving stereo.
And then you also have the ability based on the way the track was recorded to preserve or isolate those vocals and Center Channel information using the Acapella preset.
And these are just some of the incredible things that you can do with the Center Channel Extractor inside of Adobe Audition CC.
