I have for some reason developed large latency when playing soft synths through my A800PRO. I use Traktor Kontrol S4 which at its lowest buffer size in ASIO at 64 samples with 9.8ms makes no difference? (same issue is also evident with Focusrite VRM box as soundcard)
In Midi Playback settings I have adjusted PLAYBACK milliseconds buffers to all scales but still suffer with large midi playback latency. I have detached all other midi devices etc etc.
Interestingly if I open up preferences and do nothing to any settings and just close the box , I will now have normal midi playback on all my soft synths with no latency, but as soon as I press play on a project , latency is once again an issue. Open up Preferences, close it, no latency, press play>Latency!!!!!!!!!!! Can keep repeating the above with the same effect
 
Everything has been ok until the other day when it happened for no apparent reason
 
Any suggestions or help please
 
X2 Producer
W7 64
i7
12gb

A bit of progress, I have started a new project and all is ok (after all maschine standalone and the controller work flawlessly) so a new Sonar project is all good.

Open up any previous project that I have been working on and the problem re-appears!!!!!!!!

However after do some searching here, I have now enabled the PDC button on these projects with the latency issues and the problem goes away.

Not sure why as i can disable all fx and plugins with no strain on the program and processor but will still have latency until I enable PDC?

It is probably a latent effect you added in your ongoing projects. Things like perfect space and rmix add latency. Disabling PDC (plugin delay compensation) defeats that latency, but those effects are no longer properly synchronized. Also, until you have pressed play, the PDC has not been established. So when recording, best not to use those effects.

Look out for, as jason r stated, perfect space.
 
Any convolution reverb, or effect with "look ahead".
 
Either the LP64 multiband or LP64 eq can cause similar, as can  ProChannel CL.  Simply turn them off when tracking.

Thanks guys, will make a detailed search when I can, to find out what is causing it, with the above in mind.