Hi - I have seen this with both the 2017 01 (Jan) and 2017 02 (Feb) Platinum versions, where with Sonar running with a project loaded - and just sitting there, using the ASIO drivers of my audio interface, where playing something in YouTube or Windows Media Player - the Windows audio is distorted by some kind of repetitive under tone.
 
The Windows Default Audio Device is my HDMI output to my HDTV - and it functions perfectly if Sonar is either not running or running but without a project loaded.
 
Sonar is using the ASIO drivers of my audio interface, and its sound is absolutely wonderful.
 
I have never experienced this kind of problem before, and am wondering if anyone else has encountered anything similar, and if so, what they did to resolve the issue.
 
This issue occurs with me not even doing anything in the Sonar project - not editing, not playing back, not even the active window - just having a project open.
 
A very confuddled Bob Bone
 
 

All my audio passes through my ASIO drivers and my interface. But every now and then, I will go to watch a video in a browser either while Sonar is running or even after I've just closed it down, and the video audio will be completely garbled and distorted. I've never worked out what causes it. 
 
Also, in the past few weeks there have been a couple of times when Sonar has been sitting idle in the background with a project loaded as I've been surfing the web, and it has crashed without me even touching it. It seems like there are currently potential conflicts between Sonar and other apps but I'm not technical enough to be able to get to the bottom of it. 

Way back when there was lost of hubbub about we should disable HDMI audio as it interferes with ASIO. 
So I always recommend that. I have always just used my audio interface for everything on 2 of my computers without issues. I don't even install the mobo audio drivers ,,but now of course W 10 does that without my intervention so I have to disable them again from time to time.. 

I had always seen the recommendations to disable the HD audio because of experiencing audio problems within Sonar, but I do not recall anyone indicating problems with the HD audio playing outside of Sonar.
 
I have used the HDMI port on my computer for years, to play Windows-managed sounds like YouTube videos and Media Player audio and such, and this issue is really quite recent.
 
I use my HDTV's speakers for my computer's audio - so if I disable the HD audio how would I play system audio through the HDTV's speakers?
 
And again, Sonar is not having any audio issues, nor is it pointing to the Windows audio drivers, rather, it is pointing to the ASIO drivers of the audio interface, and playing back sound perfectly.
 
Bob Bone

Well as I say, I've always disabled any on board audio and used my interface for all playback. My DAW uses 2 different interfaces listed in my Sig. The Focusrite has no problems at all, but the Tascam sometimes needs resetting after playing a uTube. I think this is the 44.1 vs 48 conflict. 
 
My office computer has a PCI audio interface, old Card deluxe made for a radio station. It has W10  ASIO driver on their site. I have my old Tannoy Monitors hook up.  And we watch movies, uTubes and every darn thing as well as I have Sonar installed which I don't really do much with. And it has always worked as well for everything. I disabled the HDMI and on board on that machine as well. 

I never did any of that (disabling HD audio) or anything, never even done any enhancements except run my pc in high power mode. and I have my Focusrite connected to my big knob (with 2 sets of speakers) and my desktop speakers connected to my pc output. all good here.
Matter of fact I was watching you tube today while working on a project. both audio play simultaneously without issue. Sorry I know this is of no help. but at least it confirms one user with no issues.