Working several years with Live and did not really notice PDC issues during that time.
The release and all that talk about PDC was going on my nerves so i thought i would have to do a test myself and one that is at least close to features i use myself.
So based on what i was reading here I decided to do a test with a buffer of 512 and in Live 9.1.1 64-bit (on Windows 7 64-bit).
I created two tracks with a Saurus pad sound where i reduced the attack and release to 0, turned off internal FXs and and panned the two tracks hard left and hard right.
In track 1 no FXs added while in track 2 i added (all FXs switched on):
TAL Chorus-LX and ArtsAcoustic Big Rock Phase Shifter, PSP NobleQex (EQ), Stillwell Audio Bombardier Bus Compressor.
Here are some tests and the results:A) PDC switched on, no automation used
After rendering audio, listening to the audio and also checking inside Wavelab Elements 7 i did not find any delay with the two stereo channels that coorespond to the synth without and with FXs.B) PDC switched off, no automation used
Without PDC there is indeed a delay that corresponds to around 4 x 512 samples (with the 4 FXs mentioned above used). So each FX adds the size of the buffer like others mentioned here.C) PDC switched on, automation for the track volume used
Now i tried to do a test for automation of the track volume which is one kind of automation i use quite often.
I had set the automation in a way that for one of the sustained chords for the pad sounds the volue is set to 0 which means with this chord no sound should be noticed.
I rendered the two Saurus tracks (again panned left and right) to a new audio track.
In this case (buffer at 512) the result looked like this:
There seems to be some delay with the auomation and at the stereo channel with the 4 FXs i hear a very short sound while the other stereo channel stays quiet like intended.
I then tried to change the buffer size to 256 and then 128 and the results looked like this:
- buffer at 256:
- buffer at 128:
With 128 the delay almost completely seems to disappear and the sound is too short to really notice it.
With the example at a buffer of e.g. 512 this could be corrected by slightly shifting the right border of the automation:
The reason why i never noticed this could be based on the fact that in a busy track with layered sounds and/or multiple sounds playing at the same time this kind of very short unwanted sound is hard or impossible to notice.
It is only really easy to notice if you really have a silent part like in this example.
Of course it also depends on how many FXs you use in one track and how much buffer you are using. Finally this should mostly happen when using automation which is not always the case.
While this indeed is not really nice it will not really hold me back from using Live in the future. In almost any case it should be possible to solve this when needed.