Why is an XA30.5 a bad match for Revel Ultima Salon II speakers?

here is a link to the imp & phase plots for your Revel M106 stand mounts:
http://www.stereophile.com/content/revel-performa3-m106-loudspeaker-measurements#ljf3ojqamBz1KzED.97

tough imp & phase plots once again...
And, here is a synopsis of its specs:

http://www.stereophile.com/content/revel-performa3-m106-loudspeaker-specifications#usPtaevBJxpkUyqE.97

with a -3dB at 59Hz, it's easy to see why the 1812 Overture canons are lacking. Your stand mounts just don't have the capacity to reproduce such a low freq. When we say -3dB at 59Hz the SPL/volume is half (-3dB) at 59Hz. The SPL is probably back to 100% at a much higher frequency such as 90-100Hz. So, essentially, you have very bass coming from your M106 speakers & I think you wrote that you use a Velodyne sub - I can see why. 
The XA30.5 "sees" the x-over of the M106 & this x-over is providing a high impedance to the bass frequencies so the XA30.5 is probably sending very little power to those low frequencies. IOW the XA30.5 is probably not taxed much at these low freq due to the M106 design.

For the Ultima Salon II speaker, it's a different ball-game. The -3dB freq is 23Hz & 23Hz is in the deep bass region (unlike the M106). Now the XA30.5 will "see" the Ultima Salon II x-over & this x-over will demand lots of power into these low bass frequencies. I expect the XA30.5 to run much hotter temp wise as it tries to deliver power into these low frequencies & the XA30.5 will get taxed much more than it ever was with the M106.
So, yes, I expect the dynamics to worsen at 80dB SPL with the Ultima Salon II.

One more thing to remember (that many forget) - even if the Ultima Salon II are 23Hz capable, does not mean you will be able to reproduce 23Hz in your room. Based on your room dimensions you will be able to support a certain min frequency.
Here is a room modes calculator that will show you what the min freq your room can support:
http://amroc.andymel.eu/?l=19&w=17&h=9&ft=true&r60=0.6  
 

So in simplest terms, I can think of the impedance curve as an inverse current requirement curve? I can see that the Salon II would take a LOT more juice all the way from 600hz on down, and even more so below 50hz. I can definitely see how any music with significant content in the bass region would demand a lot more from the amp with full range speakers like the Salons.

It looks like even the "friendlier" Wilson Sophia 2 would be a significant increase in workload.

Thanks for helping me understand that!

So in simplest terms, I can think of the impedance curve as an inverse current requirement curve?

yes, in the simplest terms that is correct.

Thanks for helping me understand that!

welcome! glad I could help.

Thanks for the link, it was a nifty tool for discovering I needed to tighten up an air conditioning duct cover when my Salon 2s made it buzz at 20.1 Hz!

Get Pass 350.8 350ch plenty of power.