change at all, which means everything well below it gets “lifted up”. (If you take this just a bit further, you’ll figure that all audio exactly at the Threshold will have half of the Range’s value in positive gain).
ONE MORE WAY TO THINK ABOUT IT
Here is another bit of help so that you can really learn and use the power of the LinMB to its fullest capability. We’ll take another example from the Waves C1 Parametric Compander, our one-band processor (it also does wideband and sidechain). It has a typical ratio and makeup gain control and has been widely used for upward compression (both wideband and split-band parametric usage).
The Linear MultiBand Parametric Processor has a very similar compressor law as the Waves C1 and the Waves Renaissance Compressor. This model allows the “compression line” to return to a 1:1 ratio line as the level continues to increase. In other words, there is no compression of the low signal, compression around the Threshold, and once the signal goes quite a bit past the Threshold, the compression tapers off back to a 1:1 line (no compression). In the graphic shown, you can see this exact type of line. The ratio is 2:1 and the Threshold is –40dB. The line is just curving a bit (-3dB down point) at the –40 input (the scale at the bottom). Output level is the scale on the right vertical edge, and you can see that at about –20dB, the line starts curving back to a 1:1 line.
So, very high-level audio peaks between 0 and –10dBFS are not touched at all, audio between –10 and –40 is compressed, and audio below –40 is not compressed, but is clearly louder at the output than at the input. This is low- level compression, or “upward compression”. Such a trick is very useful and has been implemented by classical recording engineers, mastering houses, and classical broadcasting. Low-level compression can “lift” soft sounds up gently and leave all the high-level peaks and transients completely untouched, reducing the dynamic range from the bottom upwards.
We did say that the LinMB was “very similar” to the C1, but different in a significant way: the Threshold defines the midpoint of the Range. Therefore, to achieve the same curve in the LinMB as shown here, the Threshold on the LinMB would actually be about –25 with a Range setting of +15.5dB. Now this is a very large amount! The example shown here was merely to make it obvious; we picked the 2:1 line only because it is easier to see on the page. In reality, low-level compression that lifts the softer audio up 5dB is equivalent to an approximate ratio of 1.24:1. Lifting the low-level up about 5dB is a good
