I absolutely love Sonar but I went to stretch just a short piece of a vocal take and all these weird, gargle type sounds appeared. Maybe I'm doing something wrong? I don't know but it worked perfectly in Reaper. I held down ALT and left clicked till I got a yellow line as per the tutorial vid I watched. I also tried using AS but was not successful there either. I would think as awesome as Sonar is this would be a simple, sound good accomplishment. Am I missing something?

What you are hearing is the "Online" warping algorithm and is only meant for auditioning the changes. You have to bounce the clip using the higher quality "Offline" algos to get rid of the garbled sound. Those settings can be found in the Inspector. Check out the manual for more details. It's a little involved.

Thanks Beepster. I wish it wasn't so complicated. Sonar is my main DAW and stretching a clip should be an easy task. Not that it's complicated to do but I mean it would be nice to hear the results within the program as opposed to having to bounce and choose the correct algorithms. I guess I'll just use Reaper for edits like this. Now that I think about it maybe Melodyne Essential can do it?  

From what I've been told you may need to upgrade the include version of Melodyne to access the fancy time stretching stuff... but I do not know as I have not upgraded to X3 yet.
 
Audiosnap is indeed a bear and one of my issues with X2.
 
However one thing you may want to try is fiddle around with the various Online audiosnap settings because different online algos will work better for different types of audio.
 
There is also the Loop Constructor view which is kind of an outdated way of doing things and perhaps more effort but with a skilled hand and the right knowledge looks to be very accurate and removes the whole auto processing element... but I'm still learning about that feature myself and I'm not even sure it is still included in X3.

timestretching is super easy and also sounds great in sonar. You dont need to use Melodyne, just the Izotope radius algorithms that come stock. I use a key bindings to perform bounce to clip with one key stroke, the stretching itself is simply a ctrl+drag procedure. 

Thanks Beepster. I just found out it is possible to stretch notes in ME so that's a good thing. Audiosnap is complicated but I pretty much have it down. Well... for the most part. I don't use it that often so I still have to think about the controls and what their functions are but after a few minutes it comes back to me. 
 
X3 still has loop construction. I haven't played around with it that much accept for lowering the volume level on certain parts of a loop. That's a pretty cool feature but I'm not sure how deep it goes. Guess I'll have to set some time time aside and experiment more with it. 

Thanks perfectprint. Yes. The process is easy but the artifacts it added to the sound is what threw me. Are the Izotope radius algorithms set by default in Sonar? Also, once I've stretched the audio to its desired length will just the standard bounce to clip get rid of that grainy, gargle sound? 
 

The default time stretching at playback is preview quality. However when you bounce it will use higher quality stretching. The settings for stretching are in the clip inspector.
You can get even better quality stretching by first converting your clip to an ARA clip and then slip stretch it. It will then use the melodyne stretching algorithm which sounds really good even at playback time.

Geo524
stretching a clip should be an easy task.

The math is pretty complex, and the results are understandably hit and miss, and a vocal is one of the most difficult substrates to  process. If you mean you would like to be able to push a stretch button and have it magically done, then yes I agree. Good if you can get it. But there is no way that getting it with no "artifacts" is an easy task for your computer. No wonder offline is the only way to get a decent rendering.

Nice tip Noel. Thanks! I just tried it and it worked like a charm.
 
By convert to ARA clip, that's the same as Region FX > Melodyne > Create Region FX. Right? Or is there some other way to create an ARA clip?