Expander (audio)
Expanders belong to the group of dynamics processors .
They are control amplifiers , which expand the dynamics of sound information that was compressed in its dynamics at the beginning of a transmission path in order to preserve the authenticity of the acoustic event.
The expander lowers small amplitudes (level), but leaves larger ones unaffected ( downward expander ). An upward expander raises larger levels, but leaves smaller levels unaffected (e.g. Urei LA22). Expanders are used to suppress noise and to shape the sound. A threshold value, below / above which the lowering / raising should be effective, and the amount of lowering / raising (ratio) can be set. To avoid noise , upward expanders are usually used together with gates .
In music, sound modules - electronic sound generators without a playable interface or sequencer - are also referred to as expanders because they serve to expand the supply of playable sounds. They are mostly controlled via MIDI . Such expanders can also be full-fledged synthesizers , which differ from these only in their much more compact design and the lack of a keyboard .
literature
- Roland Enders: The home recording manual. 3. Edition. Carstensen Verlag, Munich 2003, ISBN 3-910098-25-8 .
- Hubert Henle: The recording studio manual. 5th edition. GC Carstensen Verlag, Munich 2001, ISBN 3-910098-19-3 .