Transcription
Welcome back to the channel. Today, I wanted to make a quick video showing an often overlooked and underappreciated compression feature. This is just as useful whether you're producing, mixing, or mastering music, so hopefully, there's something for everyone. So let's just get right into it.
This technique can be applied with almost any compressor, whether it's free like this Catelnikov here, or analog or digital modeled compressors. They all tend to have a very similar feature available to them. I'm going to be demonstrating using this Pro C2 because it's very visual; I can easily show what's going on, but I'll also show how to apply it in other compressors.
This feature allows the compressor to work much more naturally with the groove of a song and prevent unnatural overloading or pumping effects on a compressor. And it's especially useful on signals that have a lot of low end, like drum busses, full mixes, or even acoustic instruments that have been close-miked and have a lot of low end. So let's take a listen to this drum bus that we're going to be affecting today.
[Music]
So you can hear and see right away that there's a lot of compression kicking in. It's being triggered by that bass or kick drum. See, every time there's a kick, we're getting a lot of compression; it's squashing the track down, everything's being lowered, and it's struggling to recover.
To get around this, compressor designers have done something very clever, and sometimes it's a little bit hidden on some plugins. What most compressors do is they have their original signal, which the compression will be applied to, but they also have a duplicated signal, which is sometimes called the side chain or the detection circuit. And it's this signal that the compressor is going to listen to to determine what compression to apply to that original signal.
Now, I know that sounds a little bit complicated, so we'll just get straight back into an audio demo. So in this compressor, you can access it with the side chain down here, but it's not a typical kick and bass external side chain; this is an internal side chain. And what I like about this compressor is we can listen to that detection circuit to hear what the compressor can hear. So if I press audition, you can hear that the compressor is listening to everything low end, which is triggering the compression, and the high end. And if I turn the filter on, now the detection circuit of the compressor can't really hear that low end anymore. It's applying compression to the original signal based on just these upper and mid frequencies.
So if I turn off the auditioning—I don't want to listen to the side chain, I want to listen to the original signal—now you can hear and see that all parts of this drum bus are triggering the compression in a much more equal way. So the snare, the kick, the hi-hats—we're getting a bit of compression triggered by everything—and as a result, the drums groove a little bit better. The compressor is working with the groove instead of just slamming compression on every time there's a kick drum. So let's take a listen with and without the filter.
[Music]
So you can hear right away that when we don't use this filter, the compressor is just being overloaded with that low end, and that triggers just a huge amount of compression. So, of course, it's not a completely fair before and after because I didn't exactly match the amounts of compression, but the reason people use these filters is simply to avoid that low end overload in the compression circuit, so that you can get a more balanced and natural-sounding compression.
You can probably imagine so many useful applications for this: not having the low end just triggering a compressor in mastering; you can have the overall mix triggering the compression instead of just the sub just kicking in that compression the whole time. For instance, on an acoustic guitar, you could have the melody triggering the compression instead of just the low bass notes just kicking in the compression the whole time. So there's lots of useful applications for this, but there's just two things I want to clear up first.
I just want to clarify that this is what the compressor is listening to; it's not allowing the low end and the high end to pass through uncompressed. It's just that the compressor is listening to this and then choosing to apply compression to the original signal based on what it's hearing here.
Many people quite rightly ask, but isn't this just the same as multi-band compression? So if I load up a multiband compressor—and this is an excellent question—where this differs is that a multiband compressor is listening to a band of frequencies and only compressing that band, and it's allowing the other bands to be either compressed differently or not compressed at all. Whereas with the side chain filtering, this is a single-band compressor that's listening to a selected band of frequencies, and then it's still applying compression to the low, mid, and high altogether. And that's the part that's very easy to misunderstand, even if you're reading the manual for these plugins. It's very easy to think that you're just allowing the bass to pass through unaffected, but that's not what's happening. It does sometimes sound like that because the bass becomes so much more open and full.
It's called something different in every compressor; usually, it's called filter like this, and this is just the same as that Pro C compressor. This is a high-pass filter, so it's just rolling off some of the low end in the detection circuit so that the compressor is not overloaded. On this free Kotelnikov plugin, which I adore—it's one of my favorite free plugins, actually—the sidechain filter here is called Low Frequency Relax because the compressor's not listening to that as much. Just like the FabFilter, you can choose a different slope and the frequency, but it's not quite as visual as that FabFilter, but it essentially completes exactly the same task.
The last thing I want to show you is just how effective this becomes when drums become faster and also when you start adding in more stems, and I will let you listen without and with.
[Music]
You can hear that when I kicked that in, all of a sudden the kicks were punching through with the bass; they were sitting together well, and the groove just worked so much better. Often when you hear examples in solo, it can be a little bit harder to actually hear how much of a dramatic difference it makes, but when you start adding up small changes across lots of tracks, it can be the difference between your mix sounding very weak and you're not having the impact that you want, or things just cutting right through the speakers and sounding the way you want.
So that's everything for today. Do let me know if you liked this shorter style of videos. And I just want to remind people that we're currently doing a community remix competition, so you can check the description for all the details about that. And my dogs go on walkabouts, and I want to quickly remind people that I have the channel memberships and Patreon active now for my monthly live streams and further support. So thanks for watching, and I'll see you in the next one. Bye for now.
[Music]