BOB DIFAZIO: Now, to the next knob: ratio. Ratio tells you how much compression will occur once you exceed the threshold. So I play, I play, I'm not really exceeding the threshold, and then I play real loud. How much turning down is going to happen? The ratio tells you. A compression ratio of 1:1 means that whatever exceeds will be reduced by nothing: nothing will happen, so there will be no compression, hypothetically, if your ratio is 1:1. This ratio doesn't go that low; it starts off at 2:1, which is a light compression, 3:1, 4:1, 5:1. You can see I'm playing the same intensity here on my bass guitar, and every time I change my ratio, I get a different amount of gain reduction, so I'm not changing the way that I'm playing; I'm just changing the ratio. Full ratio of infinity to 1 means that the maximum amount of compression will occur, and the signal will not be allowed to pass the threshold as best as possible. 2:1 means there will be a very slight reduction of signals that lies above the threshold. So, we'll keep it a 4:1 because my ears tell me to.

Then we've got an output. What's the output for? Well, if you are going to turn down the loud parts to match the soft parts, you end up with a lot of soft parts. Your entire signal has been reduced, and that wasn't even the intention in the first place. Your intention was to make the sinal more dynamically unified, and the compressor does this by turning down the loud parts. This output on a lot of compressors is called make-up gain, and it adds back the amplitude that was lost in the process of compression. Soyou’re your gain reduction meter is telling you, "I'm losing 6 dB here," you can put that back at the output gain and you will get a dynamically consistent signal uses up the full meter, instead of a dynamically consistent signal that is much reduced from what it used to be, alright?

So, the four things you can program is when will the compressor turn down (that's the threshold), how much will turn down (that's the ratio). The two other things are how fast will turn down and how fast will it return to normal. When you look at this meter, you should be pretending that that is your hand turning the signal down, and if it doesn't look natural to you, you need to go and change your attack and release settings, so always be pretending that the gain reduction meter is in fact your actual hand.

So, this gain reduction meter is happening very quickly. It's happening almost as soon as the sound from my bass guitar happens, I get the immediate action of gain reduction. That's because my attack is fast, so you can see with this button pressed in here, I will have a fast action. Slower action means that it's going to take a second. How many seconds will normally you can use a knob to define your attack time? And you can go from a few milliseconds all the way up to about 2 seconds. This is fixed: that is what I really don't like about this compressor. You need to have a variable attack time because every sound is a snow flake, like we've just discussed, and this attack time couldn't possibly be right for all instruments all the time. Not possible

Now, we're going to change the release time. Watch what happens with the fast release. The compression starts and the compression ends relatively quickly. Soon as I take my finger off the bass guitar, the compression goes away relatively quickly. Let's use auto-release. Can you see how the compression lasts a lot longer after I take my finger off the bass? It sort of lingers? That means that the attenuation is happening and that it is slowly returning back to normal. Once the signal falls below the threshold again, you get a slower action of returning to normal volume, which is called nominal level.