Using active crossovers is not plug and play especially if you have no, or a limited, understanding of crossovers or have never done any measurements before.
The Pass Labs XVR-1 manual (on website if you don't own the unit) is very thorough, provides a general overview of crossovers and what they do, and describes several examples of how to use one and measure results. Even if you're not new at using active crossovers, it will take several reads as the unit has many settings.
The settings on everyone's XVR-1 will be different depending on the speakers they're using. Our results won't apply to you unless you own the same speakers/ subwoofers, etc. Not likely.
Once you understand how crossovers work, if you decide to skip taking measurements and adjust the XVR-1 by ear alone, it's likely you will not end up with an optimal result. If you are going to take measurements, I'd suggest Room EQ Wizard (REW). It's freeware and you can find and download it on the Internet, but you still need a mic and a laptop. Be prepared to spend several hours getting the program set up, understanding measurements, and learning how to use the program! In addition to REW, I use a test signal and a DVM to level match left and right channels precisely.
In summary, if you decide to go this route, be prepared for a fair amount of work if you're new at this. You are more likely to get better sound with a lot less work just by adjusting your room setup/using room treatments or replacing lower level components.
Hope this helps.