Compression in mastering is quite an important step which is used for making the audio dense and for enhancing its perceived loudness by means of narrowing the dynamic range. When mastering, audio engineers use both single-band and multi-band compressors, but often with additional specific functions. For example, compressors with automatic adjustment of the attack time and release are often used. It guarantees dense but at the same time musical compression without any audible alterations, distortions and other side effects.
8. Stereo-Base Widening
The sense of this process is in enhancement of stereo effect. After stereo-base widening the sound becomes wider and more binaural. Stereo-base widening is used in case the emphasis is laid not on density, but on sound capacity. Mastering is a war of compromises, accordingly, when capacity is added to the audio via stereo-base widening, it causes simultaneous dropping of its density. It makes a mastering engineer look for a compromise. In the meantime this effect can work in the opposite way. It can reduce the difference between channels improving their phase compatibility in this way. Consequently, thanks to this effect in many cases it is possible to “rescue” audio with bad mono-compatibility.
9. Exciter’s Processing
An exciter is a device that simulates saturation effect in tubes, in consequence of which harmonics that sound pleasant to the ear are added to the signal. An exciter is used in music mastering to give the audio vividness and crystal clarity. When the exciter is on, the sound becomes more distinct and clear due to enhancement of high frequencies. But unlike an equalizer the exciter doesn’t enhance frequencies, it creates new harmonics. Exactly because of that the device belongs to psychoacoustic processing. The use of an exciter in mastering is limited as it can both improve and damage the audio by turning its sound into excessively sharp and piercing.