This was an old post but it irked me enough to write a response anyway.
ORIGINAL: mb
Bob Katz does'nt even recommend Pro Tools (on mega HD systems) for mastering so i think sonar is realy out of the question with it's limited audio engine
Sonar has a better audio engine than ProTools!
ProTools: Everything is 24 bit until the summing buses. Yes, that's right, every TDM plugin in ProTools receives 24 bit audio, does it's thing at 24 or 48 bit and returns 24 bit audio (dithered or not depending on the plugin). RTAS plugins work at 32 bit. If you have several RTAS plugins one after each other, they communicate at 32 bits. The last RTAS plugin in the chain returns 24 bit (dithered or not depending on the plugin). The summing buses are 48 bit.
Sonar: Everything is 64 bit unless you insert a 32 bit plugin then the signal gets truncated to 32 bit for that plugin. So in theory, you can have a fully 64 bit audio path in Sonar. Due to the way native processing works, allot is actually done at 80 bit inside the CPU(s).
Sonar is just fine for mastering processing. (Just use something else for PQ coding).
UnderTow