I often find myself needing to slow down audio--- to say, half speed--- for a "sample" kind of track.
In older versions of Sonar I could do this quite easily, but it seems that is gone now.
I used to simply click it, double the "length" of it, and uncheck "preserve pitch" and voila, half speed.
Now I have to tell it how many beats it is, select the algorithm, etc.
OR I can click-shift-ctrl and drag it to 200%, then render. That's another long mess.
 
I prefer the lofi non-preserved pitch stretching.
How does everyone else do it?

If it's a loop, load it into Dimension Pro and play it an octave down.

To do this, I either use Reaper which has a form of digital varispeed and even better it allows the audio to retain pitch if that's what you desire, as well as normal type varispeed - think The Beatles and Rain. I've recently acquired Wave's Abbey Road Vinal, which has a slow button ala a record player. Very handy and useful. A side note, when doing this type of extensive processing - I would use 64bitfp audio files to counter any glitches or harshness that can occur.

Mixcraft does this very easily, why I bought it. Otherwise I just slip-stretch the clip in sonar/cbb. Not sure why that’s not working so well for you.

I also have an Android app that does it on the fly with little distortion. It can play whole playlists @varied speeds and/or pitches and can save changes to file.

or for $12  http://www.cableguys.com/halftime.html
 

if you slip-edit in cakewalk you have to bounce to clip to make it sound good

Riffstation is very good for altering time , tempo and pitch  ...Works great for transcribing ...
 
It is also now free ..
info
https://pro.riffstation.com/
 
free download
 
https://pro.riffstation.com/download/#
 
Kenny

My favorite software for slowing down music, assuming that you might visit other products, is - drumroll please, the amazing slower downer or AMSLO.  
 
Its pretty sweet though, to be able to provide single tracks to others to review, from Sonar, with a few simple clicks..  

kennywtelejazz
Riffstation is very good for altering time , tempo and pitch  ...Works great for transcribing ...
 
It is also now free ..
info
https://pro.riffstation.com/
 
free download
 
https://pro.riffstation.com/download/#
 
Kenny

IIRC, RiffStation is going to disappear at some point, so even if you think you will never use it, it is a good one to get. I do not think it will bake modified audio (never tried TBH), but it is a nice toolbox of audio playback functions you will probably find handy.

I appreciate all the feedback and answers!
 
To be clear: I want to destructively lengthen the audio to a percentage of its original tempo.
Now that I have a ton of third party answers, how are people doing this INSIDE Sonar?
I use the Pitch transpose (audio) and the different algorithms there, but that's just keeping it the same length.
We used to be able to shorten/lengthen an audio clip and choose the alg in the window. I can't see that any more somehow.