I just added an instance of Sup Drummer percussion and I'm getting an audio drop out as soon as it starts. 
Can anyone tell me what adjustment to make, perhaps to the buffer or what ever, to stop the audio drop out ??  Thank you.  I have to check my signature to see if my latest computer stats are accurate.  Intel Core i7-2600 CPU @ 3.40GHz 3.40 GHz Ram 12GB.  64bit op system
 
Dan

The easiest thing is use ASIO and push up your sample buffer. See if that doesn't help.

Thanks I'll give it a shot.
 
dan

Try hitting the letter 'E' on your computer keyboard to toggle off/on the bypass of all effects, just to see if that makes the issue go away.  If so, then one or more plugins are likely either CPU-intensive or are not meant for tracking (look-ahead processing, for example).
 
If temporarily bypassing effects did NOT make the issue go away, (hitting 'E' again turns the effects back on again, by the way), then it's time to look at your settings for both Sonar and for your audio interface.
 
1.  Do you use a dedicated audio interface, or do you use on-board sound?  (a dedicated audio interface is HIGHLY recommended for audio streaming, such as with applications like Sonar).
2.  If using an audio interface, what are your current settings for: ASIO Buffer Size and Sample Rate?
3.  In Sonar, what are your current settings for: Sample Rate, Driver Mode, Record Bit Depth?
4.  In Sonar, what are the reported latency values?  (input latency, output latency, total round trip latency)
 
Also, if you have not yet done so, please download and run DPC Checker (not for Win 8) and/or LatencyMon, run each one at a time, without Sonar running, and report back on any issues either or both of those show.  If you did not know, those 2 programs are freeware that show system latency that may interfere with the ability to properly run streaming audio applications, such as Sonar.
 
You can get DPC Checker here:
 
http://www.thesycon.de/deu/latency_check.shtml
 
And LatencyMon here: 
 
http://www.resplendence.com/latencymon
 
For whatever the worth, I would recommend as a reasonable starting point, setting your audio interface to a sample rate of either 44100 or 48000 hz, with an ASIO Buffer Size of 128 (if your interface expresses this as Number of Samples, shoot for something just under 200 - like 176 or thereabouts).  In addition to the above, make sure your sample rate in Sonar matches the sample rate you chose for your audio interface, and try a record bit-depth in Sonar of 24 bits.  These settings should end up giving you a pretty reasonable balance.
 
There are also buffers you could try to bump up in Sonar.   Look in Preferences>Audio>Sync and Caching and try bumping up the input and output buffers there - some suggest doing so in increments of 128, then checking to see if that helped, etc.
 
So, please review the above, and post back, 
 
Bob Bone
 
 
 

Thanx bone, I'll try this stuff out.  Sounds like you know your stuff :)
 
dan