You have the right master volume level for your system, you start Dirac Live and it's suddenly lowered to -xxxdb.. Is my unit broken? 

That's indeed 100% expected.. :-) 
Once you start Dirac live, we lower the volume  to a low level by default as a safety feature to prevent any damage during the sweeps. Same applies when you drop a Dirac filter inside the slots as the last step. 

How to deal with this volume change?  

Please check our magic Dirac Live manual p26. :-) 

Please note how you need to use the Master output fader INSIDE Dirac Live to boost the level to the correct level without damaging your speakers. 

Just remember to do the same once you've dropped the Dirac live filter inside your unit at the last step inside Dirac Live software. Simply use our IR remote or front panel knob to raise the master volume back to correct level). 

Happy listening!