Designing Audio Effect Plug-Ins in C++

CHAPTER 10

Modulated Delay Effects

Perhaps the most interesting kinds of audio effects, from both listening and engineering standpoints, are the modulated delay effects. They include the chorus and flanger/vibrato; additionally, modulated delays are also found in some reverb algorithms. These time-varying filters are actually quite sophisticated and fun to implement, and we have gone to great lengths to create useful sub-modules. These include the digital delay effect or DDL (digital delay line) module and the wave table oscillator. If you can design, build, and implement modulated delay effects, then you are well on your way to proficiency in audio effects coding. These effects have parameters and coefficients which change on every sample period. ...