why some plugins need PDC on to work and others just needs it off? Is it a matter of if its on when recording the midi for it?
Cant get to work 2 synths at the same time: 1 needs it on to sound good and on time, the other needs it off to sound without latency...
how to avoid this issue? thanks.
im running X1 x32bits Wndws7

Some plugins require looking ahead in time (i.e. examining the incoming digital audio a bit ahead of the current output) to generate their output. (That by itself can be a topic for higher math.) The DAW software compensates for these latent plugins by PDC, which is delaying all the outputs from other audio and plugins so they can all be sent to the sound card synchronized with the most-delayed output. This is the only way to get the intended sound from the project, but the latency makes live performance difficult. Turning off PDC makes the latent plugins sound wrong; i.e. the "wet" output of that plugin sounds delayed from the rest of the project, but it can allow live performance through a non-latent plugin with no latency. The advice usually given to avoid the issue is never use latent plugins until all your tracking (recording of live performance) is done.