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

It depends a lot on the type of effect. Some types of effects will always introduce a delay and it cannot be avoided. A simple example would be a compressor that has a "look ahead" feature. Well, there is no way to look ahead into the future, so the only way to do it is to delay the output signal so that the algorithm can apply the compression on the delayed audio based on the non-delayed audio.
 
But that will cause all other tracks to become out of sync with your track that has the compression on it. To get everything back into sync, the host has to then delay all other tracks by the same amount. So it asks each plugin how much it is delaying the audio, and then applies an artificial delay to all other tracks so that things once again line up.
 
Other types of DSP algorithms that cause delays are FIR filters, which will delay the signal by half the number of samples compared to the number of coefficients it has. FIR filters are "digital" filters which cannot be recreated by analog circuits, while IIR filters are the ones simulating analog filters.
 
Convolution reverbs also cause delay (but the fancy ones use complicated tricks to work around the issue, resulting in zero-latency).

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

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?

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

If I was having problems in real world use then I'd have a reason to construct some test to try and find the cause of the issue. But I dont. I suggest you do some more reading of the Sonar reference manual under PDC

Plugin and delay compensation is controlled in Preferences/Audio/Playback and Recording and also Synch and Caching

There is also a toggle for PDC in the appropriate module in the Control Bar.

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?

Ah ok sorry, I guess I misunderstood your question. But 40 -50 ms does sound excessive. I'll try your steps and see if I can repro it.

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.

I can't replicate a problem using two instances of Z3ta 2 with a patch that includes a tempo-synced delay, one with a full complement of Prochannel FX on its track, and the other completely dry.
 
Can you reproduce a problem without Blue II in the mix?