Compressor, maximizer functions

The compressor is used to control the dynamics of the sound. It is possible to produce the same result as with the limiter or maximizer, i.e. to increase the volume but to reduce the amplitude of the peaks. In a small percentage of cases, we can achieve the opposite effect. That is, we can make a sound that has lost dynamics more dynamic again. The latter option is most effective when used on solo tracks rather than on complex music. Of course, this doesn't preclude using the compressor on more complex material to increase dynamics, but in the case of a dense, continuous signal, we can only refine the sound. In the latter case, the use of a compressor may be more suitable for maximising the average volume ratio, which causes a reduction in dynamics. For complex sound samples, a multiband compressor is used. Its functions are the same as those of a conventional compressor, but it divides the frequency ranges of the signal into low, mid and high bands, which can be handled separately. The advantage is that the adjustment you make in one range is not made in the other. The dynamic range is the value in decibels between the loudest and the quietest amplitude peak. If it is high then our music is dynamic.

Suppose we have a signal whose amplitude peaks are at their maximum, but in some places, the signal is weaker. To change the signal, the following settings need to be managed..

Threshold threshold: the value in dB at which signals with amplitudes higher than the threshold will be modified by the compressor. So, if the amplitude peaks in our sound are maximised at, say, 0 dB, and the threshold is set to -6 dB, the compressor will reduce the volume of the signal by 6 decibels, but only if the ratio is at least 10:1. Compared to the first figure, the second figure shows that a compressor set to 0 attack and -6 dB thresholds will reduce the amplitude peaks to -6 dB, but will not change the signal attenuation beyond that.

Attack: The start time of the signal change, given in milliseconds. If this value is zero, the compressor will immediately perform the change for amplitude peaks where the signal strength exceeds the threshold value. If 5 ms, it will start this change with a delay of only 5 ms. Compared to the first picture, you can see in the third picture that the attack value is not zero, i.e. it has reduced the peaks with a delay.

Release: if the change has been made based on the attack and threshold value, you can specify how long the signal should try to return to its original state. If the attack is 0, this state will never occur because the attack will want to perform the corresponding volume reduction immediately. In this case, the attack and release work against each other.

If the release time is long, the modified signal will not return to its original form for a long time. If it is short, the waveform will try to return to its original shape as soon as possible, but this is prevented by the attack if its value is 0. In this case, the signal is modified according to the fourth picture. It can be seen that for a short release time, the peaks round off and become more angular. For very small release times, the chance of distortion increases in parallel. The two functions are at war with each other.

As far as possible, use the short release time only if no extreme adjustments are made to the other settings!

Ratio: This is a ratio pair. If the ratio is set to 1 or 1:1, the compressor will not make any modifications, regardless of the other parameters. If the ratio is at least 10:1, the threshold can maximally limit the volume peaks. The ratio value has the most influence on the operation of the threshold. If the original signal at a 2:1 ratio would go 1 dB above the threshold, the sound will exceed the threshold by 0.5 dB. An overshoot of 3 dB will cause the signal to overshoot the threshold by 1.5 dB.

Gain, or make-up: This is used to increase the output volume of material that has already been altered.

Input gain: Here you can increase or decrease the unmodified volume to a level where the compressor will ideally perform the operation.

Now, in theory we know how the compressor does its job, but practice makes a big difference with this device. If you have the time, roll the settings to double-check what is described here! Let's get a feel for how it works! Without it, the compressor will not be a handbrake.

The maximizer works in a similar way to the compressor, but lacks a few features. Since the attack value is fixed at zero, there is no such setting. There is also no Ratio value, because it is set to the maximum value. For some plug-in software there is a Release time, but this setting allows only minor changes. What changes significantly is the Threshold function. Here you don't tell it how many decibels to reduce the amplitude peaks by, but how many decibels to increase the input volume. With this function, you are effectively squeezing the amplitude peaks to the limit of the maximum 0dB value, or whatever value you give it. This increases the global loudness of the signal, but decreases the dynamics as the distance between each amplitude peak is reduced. If used gently, only the loudest signal peaks are pressed against the wall. If you use the Threshold more aggressively, however, there is too much interference. If there's a lot of low bass in a given band, it can be cut with an EQ. Since these frequencies are the loudest in the signal stream using the compressor/maximizer before the EQ makes a small margin. This can help to shape the volume as desired if the interference is otherwise significant.