Splajn, I’ll illustrate an example.
Suppose to want harmonize a monophonic vocal track (1 only singer) with an 8 voices choir effect, but your VST harmonizer supports maximum 4
voices choir effect (like AKAI DecaBuddy or Steinberg VoiceMachine).
How to resolve this problem?
Simple: in parallel mode, on monophonic vocal track, apply 2 (or more) istances of your 4Voices VST harmonizer effect. You have to program a
different harmony on each istance.
In this case, the series-cascade mode doesn’t work correctly: output of first istance (harmony 4 voices) goes into input of second istance,
but VST harmonizers work correctly with only 1 voice in input. Conclusion: second istance of VST harmonizer doesn’t work correctly and so you
are forced to cancel second istance and to content yourself with an only 4 voices choir effect (first istance effect).
Why?
In series-cascade mode, each DSP-Effect from 2nd to X receives in input the output of previous DSP-Effect. Only 1st DSP-Effect receives in
input pure original audio signal. In this mode, DSP-Effects sequence is very important.
In parallel mode, instead, each DSP-Effect works independently, without interfere with other DSP-Effects, because each DSP-Effect receives in
input pure original audio signal (in our example, 1 voice vocal track). In this mode, DSP-Effects sequence is not important.
I hope that my example and my explanation are clean.
VBAlk