As mentioned, the Barefaced love their power, and as good as they sound at low volumes, it is when you turn them up that the magic happens.
I was actually going to reply to an earlier post about power with Barefaced cabs but this one is continuing the same theme which isn't really correct. It's nice that people are celebrating that Barefaced cabs can do amazing things if given enough power but to say that they need lots of power or that they sound best when turned out loud is not true at all (although it may seem true based on your own personal experience - but this is the peril of anecdotal evidence).
First point: The 12XN and 10CR models are different animals.
The 12XN don't change in sound in any significant way as you apply more and more power - until they run out of power handling and then they obviously distort in a not very pretty way (and that happens well before you hit damage levels unless you're doing something really weird).
The 10CR start to growl as you push them harder, then get more grindy and eventually end up with quite a dark roar but that takes a lot of power.
If you are replacing any cab with a Barefaced cab of similar size then you will not need more amp power - they are very efficient cabs. If you are downsizing then for every halving of size you'll need to double your amp power (assuming you were taking the amp to clipping with the old rig). There's a lot of powerful amps around nowadays but a lot of cabs struggle to handle a lot of power at low frequencies so your old cab may not have allowed you to use the full power of your amp, even though the thermal power rating for the cab was more than high enough, so you may need less amp power than you think.
With the 12XN cabs, the only change you will hear as you turn up (assuming the amp isn't clipping) is the response curve of your ears changing, as described by the Fletcher-Munson curve. With the smaller 10CR cabs that will also be true at more reasonable volume levels and with the larger 10CR cabs that will be true until you get to very high volume levels (yes the 10CR speakers change in tone when you push them hard but that takes quite a lot of power and they're very good at turning watts into decibels so that equals rather a lot of loudness).
My general recommendation with amps and Barefaced cabs is to use what you already have and see how it works. Don't assume you need more power because someone on a forum uses more power with the same/similar cab - you don't know how loud they play and vice versa!
