This article tells about normalization, its essence and sorts with reference to processing Mp3 and Wav files. Improvement of quality Mp3 and Wav files is shown on an example of program Sound Normalizer.
Ways of processing Mp3 and Wav files can be divided into 2 sorts: distorting and not distorting. And if distorting ways of processing change an original relation and level of amplitudes and frequencies of a sound whereas not distorting ways of processing change level of all amplitudes equally or leave invariable level of all amplitudes and frequencies of a sound.
The most widespread distorting way of processing is 0 equalizer, and the most widespread not distorting way of processing is 0 normalizer. We will consider a normalizer in given article.
Gist of a normalization consists that an amplitude of initial beep varies, and a form remains former.
And it feel on hearing as change of force a sound or volume.
Change of volume is accompanied by change of dynamic range that is relations of the loudest value to the most silent value of beep.
Increase of a volume leads to increase a dynamic range. Contraction and reduction of a dynamic range is accompanied by music which sounds exactly, monotonously, all time with approximately identical loudness, it becomes boring, inexpressive, more plane, an expression and dynamism disappears, brightness of perception is lost.
Certainly, it is possible to take advantage of a pen or a button of volume and easier to increase volume level, not resorting to a help of a normalizer but if you have many composition it supplies notable inconvenience. Each composition has its a dynamic range and a volume average level.
If all musical compositions are executed in one style or a genre that, as a rule, it is possible will be limited to peak normalization. Peak normalization for group of compositions fixes for each composition a dynamic range at one level thus that all compositions have a same dynamic range.
If all musical compositions are executed in different style or a genre that, as a rule, resort to normalization on an average level. Normalization on an average level for group of compositions fixes a dynamic range at different level for each composition depending on average value of volume of this composition that creates sensation of identical volume at transition from one composition to another for all group of compositions.
Let's consider normalization of a sound with reference to program Sound Normalizer .
You need to open a file prior to a beginning of normalization.
The program has 2 modes: single and batch.
You can open a file in a single mode having executed a command "Open".
You can go in the batch mode having executed a command ”Batch Processor”.
You can open files in the Batch Processor using three ways:
If You execute a command “Add Files” that can select Mp3 or Wav a file or files;
If You execute a command “Add Folder” that can select all Mp3 or Wav the files which are in this folder;
If You execute a command “Add Folders” that can select all Mp3 or Wav the files which are in this folder and all subfolder being in this folder.
The program has for Mp3 files normalization on an average level with definition of clipping. As level of a sound for Mp3 files is near to peak level or exceeds that one peak normalization for Mp3 files it appears not expedient.
Combination of a normalization on an average level with a peak normalization preventing a clipping will be a optimal variant.
Clipping is a distortion of beep expressing in appearance of "hissing" and "cod".
Program Sound Normalizer has for Wav files while only peak normalization.
Before normalization fulfil test for Mp3 files and define a recommended maximum level of normalization without clipping will be the best order of performance of normalization.
The recommended maximum level of normalization without clipping is a optimum level of normalization eliminating clipping and providing maximum quality of a sound.
In the batch mode the recommended maximum level of batch normalization of the list of processing without clipping is the optimum level of normalization eliminating clipping and providing maximum quality of a sound, calculated for a current list of processing.
There is a command ”Normalize each file on a maximum level without clipping” in the batch mode this command represents implementation of peak normalization on a maximum level for Mp3 files.
Level of normalization for Mp3 files expresses in percentage concerning value in 89 db in the program Sound Normalizer. For example 89 db is 100 %.
89 db is defined by practical consideration for majority Mp3 files volume level, on which else there are no clipping.
Resume
The normalization is not distorting sort of processing.
The normalization is accompanied by change of a volume or of a dynamic range, that is the relation of the loudest value to the most silent value of beep varies.
The normalization allows to improve quality: if it for Wav files expresses by increase of a dynamic range for Mp3 files it expresses by elimination of a clipping.
Starting normalization Mp3 and Wav files it is necessary to mean, that there are 2 sorts of normalization:
Peak normalization;
Normalization on an average level.
It is necessary to know that there are 2 modes of normalization:
The single;
The batch.
The normalization of the batch mode works with a list of processing and allows to align perceived volume for group of compositions. If all songs belong to the same genre or style of music in group of compositions that usually enough and peak normalization.
If there are songs in group of compositions having different genres then it is usually necessary to use normalization on an average level. Usage of peak normalization will be enough in most cases for Wav files because often level their volume is not equal maximum and group played back Wav files on disk of usual capacity, as a rule, belongs to one genre.
Usage of normalization on an average level is necessary for Mp3 files as their level of volume, as a rule, is equal maximum or exceeds it, that calls appearance clipping. Mp3 files have a small size and consequently are allocated on a disk of usual capacity in a considerable quantity and belong not seldom to different genres of music. Usage of normalization on an average level together with peak normalization preventing clipping of beep and allowing to receive maximum quality therefore will be optimal for Mp3 files.
