I noticed ever since I started using Cakewalk (Home Studio 9) that the PRV keys labeled C0 - C10 don't jive with actual notes. C0 is actually C-1, C1 = C0, and so on. Why is this and can it be adjusted?

adjust  "Base Octave for Pitches" http://www.cakewalk.com/Documentation?product=SONAR&language=3&help=0x22B06
 

Thanks, I would have never found that. So default is 1 octave off. To make it right I set the value to -1.

Unfortunately, there is no universal standard for octave designations in MIDI. The official MIDI spec does not address it, leaving it to individual synth and DAW vendors to decide whether middle C is C3 or C4.
 
Conventional musical and scientific (not MIDI) notation calls Middle C "C4", which aligns with Cakewalk's designation. However, among synthesizer vendors it's more common - but not universal - to see Middle C designated as "C3". Consequently, whether you consider SONAR's numbering "correct" depends on what instrument you're using.
 
I can't bring myself to defy centuries of musical tradition and "fix" the PRV, dooming myself to forever having to hunt for the correct keyswitches in Kontakt instruments.

Weird, as I've been thinking about this very thing a lot lately.
 
This bugs me a lot, too. Irrationally so, as it's really simple enough to just adjust for it in my head. Though every time I come up with a melody on the piano or write down something as sheet music and move over to SONAR to program it in, I forget to adjust for it without fail. And it doesn't just mess me up composing from piano, but other instruments as well. Don't know how I didn't know about the "Base Octave" setting in the years that I've been using SONAR. Upon a quick test that it doesn't screw up my existing works, it's set. Thanks for that @scook !
 

bitflipper
Conventional musical and scientific (not MIDI) notation calls Middle C "C4", which aligns with Cakewalk's designation.

Not exactly true. Well, the first part is, as it's based on the keys of a piano, being the fourth C. Blah, blah, blah. You know that... but anyway. By default, Cakewalk instead denotes C5 as middle C. Which is likely just a product of the MIDI spec having no standardized octave numbering just as you said. Since it's simple enough to just call MIDI note 0, C0.
 
/overthoughtramble

Piano mid c is C4 which *should* be the "industry standard". 49, 61, 76 & 88 key instruments all share the same mid C note but are in different locations in relation to the 1st C. I just needed to know if it was adjustable in PRV. Thanks to scook I found it, otherwise I would never know it was there. If it's even in the help files I wouldn't know where to look. 17 yr. mystery solved.