Normalization – Normalize audio
Normalization is an atypical dynamic process, very different from compression, limitation, expansion or noise reduction:
It does not reduce the relative dynamic range of the audio signal.
It is not applied in “real time”, or at the moment, but it is a process that is carried out “a posteriori”, on the previously recorded material.
The normalizer is a device that falls into the category of dynamics processors.
Analyze the target signal, detect its highest volume peak and increase its gain to the maximum level possible without distorting.
With the same proportion the level of the rest of the signal increases.
The signal, in general, will sound with a greater volume.
It is very unpleasant to have a playlist with mp3 files playing at different volumes. However, it is possible to normalize (equalize) the volume of our mp3s.
Loudness normalizer
You can use the Loudness Normalizer to obtain a specific loudness.
Increasing the loudness to a specific value may cause clipping. To solve it, a peak limiter can be part of the process. The Loudness Normalizer increases the loudness and limits the peaks of the signal at the same time if necessary, to obtain the desired loudness.
This process takes place in several stages, first an analysis and then the final rendering.
What is an audio compressor?
When we talk about compression we also talk about dynamic range. Recall that the dynamic range is the difference in amplitude between the lowest and highest part of a signal. In the compression process, basically and technically it consists in decreasing the dynamic range of a signal.
These are the most common controls or points to control in an audio compressor:
Threshold: This is the point from which the compressor will start working. Any signal that exceeds this point will be compressed.
Ratio: This is the reason for the compression that will be applied to the signal that exceeds the threshold. We see it and find it as 2: 1, 4: 1, etc. The first number means the number of input decibels that exceed the threshold, and the second number the output decibels. In other words, for “X” number of decibels that exceed the threshold, “Y” number of decibels will be output.
Attack: It is the time it takes for the signal to compress after having exceeded the threshold. We see it and find it commonly expressed in milliseconds (ms).
Release: How soon the compressor stops working after the signal falls below the threshold.
Knee: This is a parameter that subtly modifies the compressor threshold. A low setting (Hard knee or 0) means that the compressor will act only from the set threshold. A high setting (Soft knee) will allow the compressor to act gradually from before the signal reaches the threshold. In this way, the threshold can be treated as a range and not as a specific point. As the signal approaches the threshold compression increases. When it exceeds it, it continues to increase until the entire compression ratio is applied.
