input monitoring latency

Are you using a Driver Mode of ASIO?
 
If so, what is the ASIO Buffer Size set to?
 
Also, some effects add a bunch of latency, and are not meant to be used during tracking.  If the lag goes away when you bypass all effects (hitting the letter 'E' on the computer keyboard toggles effects on or off), then your loaded effects are the culprit.  So IF that is the case (by the way hit 'E' again to turn effects processing back on), and you should consider either temporarily swapping out the reverb plugin for some 'leaner' running one that doesn't add too much latency to be practical during recording, OR doing the tracking with the effects bypassed ('E'), though the vocalist would likely not like that second option.
 
Anyways - please review the above and please also respond to the above questions.
 
Thanks, 
 
Bob Bone
 

I'm assuming you're using the Echo function in Sonar. If so, the issue is in the plug-ins with latency. What seems to happen is this:

1) Before playing the song for the singer the first time, the delay/echo might be less than 3ms. That's typically acceptable, although not perfect.
2) After playing the song once, then stopping, there's now a serious echo/delay on the vocal. Why?

After you start and stop playback of the song the VST engine remains active, meaning all the plug-ins are still active and delay compensation is working. All audio is delayed to keep all plug-ins perfectly aligned. What you're hearing is that compensated delay inside the DAW, which obviously makes the echo button function totally unusable here.

Workarounds

• Freeze all the tracks you don't need except the vocal track you're recording on. For the reverb, or even compression on the vocal track, use the lightest (non-modeled) plug-ins, such as those included with Sonar.

 

• Export a stereo mix of the song and import that stereo mix into a new (vocal comp) project, where you will record vocals. From there, you can have removed all possible latency other than the ones caused by ASIO or the plug-ins in the vocal chain. You can later export your vocals and import them back into the original project as needed. In fact, I like doing this because I can essentially do all my vocal comp'ing in one project, save it as the vocal comp project, and only import the vocal comps back into the full song project. It's way cleaner, and I lose nothing after janitorial work is complete.
• Adjust latency to the sample by using the Offset function. To accomplish this:
  • Physically loop back your audio output to your audio input with a cable.
  • Play and record the metronome to a track. You can use this loopback. Latency here doesn't yet matter. 
  • Now play back the recorded metronome to yet another new track using the loopback.
  • Compare the offset in latency between the two recorded metronome tracks. Measure the number of samples (use the ruler) that the two tracks differ in the start of each metronome pulse.
  • Use the Offset function (+/-) in Sonar's Preferences for this audio interface (be sure this one is selected before touching the offset.).
  • Retest each adjustment to how far or close your second metronome track is lining up with the first.
  • If the correct (+/-) number of samples is entered and saved, you will have corrected your hardware latency to the sample, which is better than ASIO can do.