dannyb00
 
Now, for example.... Am I wrong to say that what you hear in your headphones coming from sonar should sound the same when it's mixdown to audio?

No your not wrong. Try a different project. Make one real quick and try it and see if you still get the same results.

Many things could cause this to happen.
 
Start by checking your routing: make sure EVERY track goes either to a sub-buss or to your master buss. You don't want ANY track going directly to your main outs. Also ensure ALL of your sub-busses are going to your master buss.
 
Next, do an export using the same bit depth & sample rate as your project (24 bit hopefully!) and with NO dithering.
Now import your new export into the same project on a new track. Route this one straight to your main outs (you don't want to "double up" any master buss Fx. Solo it. This should sound identical to your raw tracks and you have proved conclusively that Sonar isn't the problem.
 
Now do the same exercise but export as a 16 bit 44.1 KHz file. Reimporting it into Sonar should again sound exactly the same.
 
Now you can try playing it in Media Player, car stereo etc. If it sounds wrong in WMP, check you haven't got any weird EQ curve in WMP

My guess is just a guess.
 
It is possible to mix at the 32bit floating point in which there is no distortion but when you mix it some aliasing somehow .
Mixdown to the same bit length and resolution as well to perhaps isolate the cause.
 
I'd suggest putting high pass filters on everything and roll off some of that low end energy that might not be within the audible range and could be stacking up in takes and tracks.
 
 
 
 
 
 
 

DISCOVERY MOMENT!
OK, so I discovered something interesting. I exported my track to audio and of course it sounded boomy and muddy. I took the same boomy and muddy audio file and imported it back to Sonar and guess what? It sounded just fine.
 
Discovery: Media Player is somehow making my audio sound crappy.... but the file sounds fine once it is back in Sonar.
Now I'm trying to see what is going on with the Media Player. I don't recall adding any Eq or sound adjustment to it.
 
Has that happened to anyone?

Only when I have rendered a mix to mp3 and forgot to lower the peaks from zero to -0.3 one time to hear it in the car or some such. But in sonar have you got 32bit floating point checked?
Is there a add on EQ to media player active? 
Anyway you will find the cause no doubt.
It is difficult for anyone remotely to advise when they don't have all the data.
Good luck, hope you isolate the cause.
Have you mixed successfully in the past and this is something new

OK, you guys are going to hate me..... The problem was Windows Media Player all along. It had the "SRS WOW Effects" settings on. The track sounded exactly as intended when I took that setting off.
 
Still, thanks so much for all your help. I learned a few things about the Export Settings out of this experience.

Dannyb00 - you could retitle your thread by appending "Solved" to it.

Discovery: Media Player is somehow making my audio sound crappy.... but the file sounds fine once it is back in Sonar.
Now I'm trying to see what is going on with the Media Player. I don't recall adding any Eq or sound adjustment to it.

This mistake happens way too often.

dannyb00
OK, you guys are going to hate me..... The problem was Windows Media Player all along. It had the "SRS WOW Effects" settings on. The track sounded exactly as intended when I took that setting off.
 
Still, thanks so much for all your help. I learned a few things about the Export Settings out of this experience.

The "enhancements" in Windows Media Player are tools of satan. I had a laptop once that defaulted to the "enhanced" settings, and it really screwed me up until I clicked through enough tabs to reach the Defaults of Evil. (However to be fair, if the definition of enhanced has changed to "atrocious sound quality that would leave any rational human retching in disgust," then the description is accurate.)