Thanks for your responses. I did get a response from Presonus after submitting a ticket. It took about 3 business days. Here is the response:
Thank you for contacting PreSonus.
Please understand that the Main Volume Dial is not designed to turn "off" when you adjust all the way to the left.
It has a range of -80 db to 0db or (unity)
You have to dial things in to a comfortable listening level.
Please refer to this article for doing this.
Dealer/Rep RA Support
Technical Support Lead
While I was waiting for this pithy response I went through every response in this section in case I missed something and I came across this:
Which discusses calibrating your studio monitors. I am new to having actual professional studio monitors so I hadn't done this before. I did try to adjust the volume on them before but it seemed liked I still had to turn them way down to eliminate all sound when Quantum was turned all the way down to -80dB. Also the studio monitors at that level worked just fine with my previous Firestudio Mobile.
It's worth it to download the Studio One software that comes free with your Quantum and use it to generate the pink noise. Instead of looking around for a pink noise VST for your DAW. I also downloaded Decibel X on iPhone for SPL meter which you can set weighting to C and response to slow.
Big question is what to set the main of the Quantum at, as according to Butch's response above, unity is turned all the way up? So I played around with it and if I tried to get 78-80 dB SPL out of my monitors with the Quantum turned all the way up then I would still get sound leaking when I turned it all the way down. I ended up settling for 73 dB SPL with Quantum turned all the way up to 0 dBfs and my monitors set to 5 out of 10. Now comfortable listening is at about 2:00 on Quantum and loud listen is between 3-4:00.
Beware when setting you levels! Remember to turn down your Quantum when you are ready to test your sound, or you will blast your ears and **** in your pants.
So the question is, what if I need these monitors in a bigger space and need to turn them up. Will I have sound leaking? Also, why don't they just have a mute button, even if it is just in the UC software???