Just what is plug-in "delay compensation" supposed to do?!?

I'm running Sonar X3e, (64-bit), on a clean and otherwise fast, low-latency system. You may be able to reproduce this issue yourselves, if you want.
 
I inserted Rob Papen's Blue II synth, and used "Guitar Groove 2", which has a nice, delay-based groove that's sync'ed to the song's tempo (in this case, 60 BPM). (Anything with a sharp attack and bult-in, tempo-sync'ed delay should work.) I used Sonar's own "ProChannel" compressor and EQ to tame and tweak the sound a bit. It seemed to play in time with the other tracks.
 
But when I added another instance of RP Blue II (using the same factory preset but no compression, EQ or other processing) and played both at the same time, live, via my MIDI controller, the original one was obviously delayed by the compressor and/or EQ. Turning off Sonar's compressor and EQ on the original synth helped put the otherwise identical synths and tracks back in sync again.

No third-party effects were used, and while I've heard similar "smearing" and other phase issues just from using the effect sends in Sonar (even with no effects on the sends!), I didn't really expect it from the compressor and EQ (though I guess I should have).
 
So, what is "enable delay compensation" supposed to do for the VST? Per the manual, I left it where it is for each VST, but if Sonar's own effects are adding that much delay to the track, I don't know what to do!

And yes, the search engine for this forum sucks (as others have noted), so if this has been asked and answered any time other than the one hit Google showed me from 2008, I apologize.
 
Thanks.

Steve

Thanks, SilkTone. I pretty much knew that stuff. I guess I should have asked why Sonar's own "ProChannel" effects are adding so much latency that it's clearly, audibly noticeable.
 
I could understand it if a third-party plug-in didn't "play nice" with Sonar and allow it to compensate for whatever delay the plug-in creates. But these are Sonar's own plug-ins! How did this get released like this?!? And how am I supposed to work with this?!? What's the work-around?
 
Steve

mudgel
Do you have Use Plugin Delay Compensation turned on?

I make use of ProChannel plugins and other Cakewalk VST2 plugins and don't experience this.

Are you using the plugins in the monitoring chain? It may not be plugin delay but system latency in connection with your PC and sound card settings?

Have you tested this yourself though? Try the steps I outlined earlier, and if you use a delay on the plucked instrument sound, make sure it's built into the instrument, and not added as another VST effect. Play them both live (via MIDI) at the same time, and I bet you'll hear a difference between the "processed" instrument and the unprocessed one. (We're talking something on the order of 40-50 milliseconds, at least, if I had to guess.)

I don't know where I can turn compensation on or off for Sonar's own plug-ins in the ProChannel. I can hit the "PDC" button, and try that, I guess. But yes, I'm using them in the "monitoring" chain of the VST, though as I said, I'm playing both instances of the softsynth via MIDI at the same time. The output of one goes through the compressor and EQ in ProChannel; the other has nothing on the output. I'm not using any plug-ins on my audio device's monitoring chain. This is all happening within Sonar, and only with two instruments (really, one that's loaded twice) and no effects other than ProChannel's compressor and EQ.
 
Steve

40-50 ms is huge. I can't imagine any equalizer having such latency. Makes me wonder if this has anything at all to do with PDC. I'll bet if you froze the two synth tracks (leaving the fx bin active) they'd be in perfect sync.
 
Do you just notice this effect when playing the synths live, or do you also hear the lag during playback?

I don't know the way you set this up, but one thing that may have an effect is that PDC can't be calculated correctly if you alter something that changes the delay of the plug while the transport is running.

bitflipper
40-50 ms is huge. I can't imagine any equalizer having such latency. Makes me wonder if this has anything at all to do with PDC. I'll bet if you froze the two synth tracks (leaving the fx bin active) they'd be in perfect sync.
 
Do you just notice this effect when playing the synths live, or do you also hear the lag during playback?

I didn't record the tracks, because it was hard enough to play the part properly with one track so far off from the other. (And yes, I could simply apply the same ProChannel settings to the second synth, but that doesn't "solve" the problem; it only masks it.)
 
The original track was recorded, and seemed to be in time with the other recorded tracks. But when I also played that synth live with the new one, it was delayed.
 
I really hadn't noticed anything this bad in any other project I've ever done. I've had some latency when tracking, but I adjust it using the ASIO settings. This isn't about that, though--this is just from running the synth's output through Sonar's own compressor and EQ.
 
I'll try freezing the tracks to see if they line up. And you're right, they probably will. But that doesn't help me the next time I want to record two synths at the same time, where one has some compression and EQ applied and the other doesn't.
 
Steve

Here's what I found:
In a new file, added the second instance of the same synth, but with no ProChannel effects. Same problem as I described earlier, and this is with ASIO set to 4ms.
 
I hit the "PDC" button, which did line up the synths, and did remove the delay from the "processed" synth. (I hadn't hit the "PDC" button before this, because I have never noticed the issue to be this bad.)

However, disabling PDC had no effect: the synths were still locked together and playing at the same time, just as if PDC was still enabled! Toggling PDC on or off after the first time I enable it seems to make no difference.

But the bottom line is that after I enable PDC once, I can play the two synths together with no audible delay on the processed one. I have no idea why disabling it doesn't seem to alter "delay compensation", but at this point, I don't really care.

Thanks for the suggestions, everyone!
 
Steve
 

Sanderxpander
Did you turn it off on purpose? It has always been on by default for me.

Glad it's working for you now!

I never changed it from X3e's default settings. Up until this issue, I didn't even know where to find the button!
 
So it's supposed to be enabled (and lit up) by default?
 
Steve

Wouter Schijns
From what I've read, the PDC is there for bypassing latency compensation on Live Inputs.
It affects only the monitoring while delay on recording/bouncing/export still is compensated.
I don't know if it bypasses delay compensation on VST recording.
But either way, if it helps you can turn it on because what you record is not changed/moved, that's how I understand it.

That was my understanding too. But all I know is that if I enable it at least once, it doesn't seem to matter what I do with it after that--the latency induced by Sonar's own effects is compensated for, and I can at least play the synth!
 
Steve

Yes, Sonar messes up the delay compensation sometimes when settings change during playback. I posted about this last year sometime, but because this forum software is shocking and/or old posts have been deleted, I can't point you at the thread, sorry.
 
Generally speaking, stopping playback and resuming it fixes the problem, as it is able to recalculate the plugin delay compensation. But a send or plugin enabled during playback may end up slightly out of sync with other plugins.