Flexible Real-Time Reverberation Synthesis With Accurate Parameter Control
Reverberation is one of the most important effects used in audio
production. Although nowadays numerous real-time implementations of artificial reverberation algorithms are available, many of
them depend on a database of recorded or pre-synthesized room
impulse responses, which are convolved with the input signal. Implementations that use an algorithmic approach are more flexible
but do not let the users have full control over the produced sound,
allowing only a few selected parameters to be altered. The realtime implementation of an artificial reverberation synthesizer presented in this study introduces an audio plugin based on a feedback delay network (FDN), which lets the user have full and detailed insight into the produced reverb. It allows for control of
reverberation time in ten octave bands, simultaneously allowing
adjusting the feedback matrix type and delay-line lengths. The
proposed plugin explores various FDN setups, showing that the
lowest useful order for high-quality sound is 16, and that in the
case of a Householder matrix the implementation strongly affects
the resulting reverberation. Experimenting with delay lengths and
distribution demonstrates that choosing too wide or too narrow a
length range is disadvantageous to the synthesized sound quality.
The study also discusses CPU usage for different FDN orders and
plugin states.