The next device I'd like to look at is the downward compressor.
Now, when someone says put a compressor on it, or
just someone refers to a compressor, they are referring to a downward compressor,
which is reducing the level of the louder things.
There are upward compressors, which bring up the volume of the quiet material, and
that is an important tool, but when someone says compressor,
they really are referring to the downward compressor.
It's a really important tool.
It's one you really need to understand the fundamentals of, but
don't expect to master it in this week.
It's gonna take you a long time.
It really is hard to hear what this does.
Mainly, because the inbuilt gain control that we talked about earlier,
it's always functioning.
And we're also not really trained to focus on the fine points of volume,
it's a tough thing.
So, the goal of a compressor is to reduce the level of the loud stuff.
We set a threshold and that's the point where the compressor starts reacting,
as the envelop gets above that, the volume comes down, to reduce that level.
The speed that that volume moves in,
how fast the reduce of the level, is your attack and your release time.
And they have a really important role in a compressor.
In a compressor,
one of the main things you're doing is trying to control that transient.
That initial sharp moment that happens, like when a snare hits or
a kick drum hits.
And it's really fast, and that attack time controls whether the compressor
brings down that initial attack or not, and if you increase the attack time,
it will actually let through that transient, and
if you reduce the attack time, it'll stop that transient from happening.
So, the thing is, there are many ways in which we can use a compressor.
It's not just to reduce a transient.
Because how I adjust that attack and
release time can really decide whether I let that transient through or not.
So, it's a complex device, and all the controls are interrelated.
Were going to take some time today to learn the fundamentals of it, and
I really hope you go to the discussion boards and talk about the many ways
a compressor can be used, and the different types of compressors.
We find that, in the abstract here,
we talk about it as if it's this simple formula.
This kind of on/off, if it crossed the threshold it does this,
if it doesn't cross the threshold it does this.
But the truth is, it's a little more complicated than that.
There's always fine details like, does the volume fader move down linearly?
Or, does it have a curve to how it moves?
And all these things are in the design of the plugin or the piece of hardware.
So, I find that choosing a different compressor can have a major impact on
the sound of it and how it actually shapes the sound.
So, bring that up in the discussion boards.
It's a great discussion to have, and I really hope you do expand on this topic.
But right now, let's look at the fundamentals of compression.
>> Now, we're going to look at the fundamentals of compression.
And like with the gate example, we're going to start with kind of a non-musical
example just designed to show us what the controls are.
And then, we'll move to a more musical example afterward.
The sound we're using this time is a synth patch I created that just changes in
volume drastically.
Let's hear it.
[SOUND] So, it just jumps up and down in volume.
[SOUND] Now, we don't really need to hear it that loud.
All right, now, we're going to see how compression functions on the sound.
The first thing we'll do is put the compressor in limiting mode.
So, we're gonna do quite, quite a bit of compression.
I'm using the ratio all the way up to 30 to 1.
Again, I think, it's important to hear what the effect is in the extreme.
And then, you can back off and use it in a more musical manner afterward.
Remember, that our transfer function is this diagonal 45 degree line,
meaning input does equal output.
And right now, we won't do anything to the sound.
If I want to have an impact on the sound, I have to lower my threshold.
[SOUND] And I'll lower my threshold right to about here,
which is just above the quite moments in the sound, and let's see what this does.
[SOUND] So, we're seeing that the compressor is automatically
reducing the volume of the louder moments and keeping the quieter moments quiet.
So, you can see we've dramatically reduced the dynamic range by compressing or
lowering the volume automatically when the loud moments occur.
We're using a high ratio, so this is having a very dramatic effect,
and we end up having a quieter overall sound.
Now, a common approach of a compressor is to reduce the dynamic range, and
then bring a volume of everything up at the very end.
This will increase the perceived loudness of a sound,
really by making the quiet stuff louder.
And, that is what the output gain section on a compressor does.
So, if I have the sound like this now,
I can increase the output gain of it dramatically.
[SOUND] And we can see that there's very little dynamic range,
and in effect, we brought up the level of the quiet moments.
So, that's a common usage of a compressor.
Now, most compressors will also include some sort of auto gain or
auto makeup gain option.
I prefer to keep that off at all times, so I am manually and
purposefully adjusting all the gain stages.
When you have an auto gain section on, the device will automatically increase gain,
and it's hard to know exactly what the compressor or
gate is doing in those instances.
