If you don't have a separate mastering app, you should save from SONAR as a 44/16 file - using one of the POWr dithering options

I have a similar issue-I record and mix in sonar 8.5 then burn to a stereo file at 44/16. I then listen to the stereo mix-the perceived volume is the same as the mixdown volume.   I have used the cd burning programs in sonar, pyro, nero and Windows media to then burn the stereo mix to disc and resulting audio is quieter no matter which program I use to burn to disc.  The resulting perceived volume drop is very noticeable and can really detract from the finished product.
 
any suggestions would be appreciated..
dennis

Firstly, it would have been better to start a thread of your own instead of waking up a five years old thread.
 
In the struggle to get a "commercial" level final wav it does not matter what you hear, because what you hear depends on the position of the volume knob. You have to look at the level readings. What you burn on a CD surely is exactly as loud as the original wav, there's no volume adjusting involved in the burning process. Also, comparing the volume of a CD played by Windows Media Player to that of the project played back in SONAR is meaningless.
 
The perceived volume is most accurately shown by the RMS volume level, which is the average. IIRC the RMS of around - 6 - -12 dB dB is somewhat OK (others please correct if I remember wrong). SONARs track meters can show RMS as well, IIRC. The peak volumes are practically meaningless. High RMS levels are reached for example by 
 
1) Volume automation on individual tracks when necessary
2) Compression and EQ on individual tracks
3) Compression/EQ/Limiting according to need when finishing the mix and exporting/mastering
 
 
 
 

Or is it a typo, do you actually mean 24/48, which is commonly used good choice to export the stereo wav- file which is then separately mastered?
 
Maybe that is where I made my mistake. I typically master without exporting. I tried it once and did not realize a benefit, but I did not export at 24/48...or I don't think I did. I will have to revisit this.

Why on earth record, mix or master audio at 64bit depth?

No audio interface can record or play back at anything like that bit depth, 24 bits is the usual interface maximum (and minimum). All 64 bit audio achieves is filling up huge amounts of disk space with padding-out zeros for no gain at all.

Unless you mean you run 64 bit Windows and 64 bit Sonar, which is quite a different thing to recording at 64 bit depth.

I'm leaning towards ReplayGain as well.
 
Some have a setting to use it when burning, "if available", as they put it - if there is a field in WAV header or something. But that would mean it depends on Sonar to some degree - don't know how that works. But there is something called Album Gain and Track Gain and you can select in burner if to use it.
 
Other software use it when ripping CD's - so you have to turn that stuff off in settings if not to alter CD's from original too much. I guess a lot of people rip for mp3's for their mobile devices and might want them adjusted.

Kalle, thank you for your reply.  here is what happens-I record and mix a project in Sonar.  Once I have mixed and I have  gotten it to the volume level I want, I mix it to a stereo track and then I listen to it thru windows media player.
I usually find that the volume level is still good and then I burn it to CD.  I then listen to the cd thru windows media player thru the same system without touching a knob or making any adjustment of any kind and I find the volume to be lower to my ears--by a noticeable amount. I can take the stereo mix that I used to burn the cd and import it back into sonar and the volume is good again-same as it was in the original mixdown again all thru the same system.  So it seems to me that I am doing something in the burning process that is dropping the volume.
that is what puzzles me