I guess it comes down to what is too loud, are you just trying to adjust the volume to a low background level or is it really LOUD at 9 o’clock? In which case you either have extremely efficient speakers or your source has a very high output.
I have my 3BST and BP25P wired with both RCA and XLR simultaneously, the RCA’s run via the Velodyne x-over, while the XLR’s run direct to the 3B allowing me to bypass the Velodyne. I’ve not noticed any appreciable change in volume when switching from one or the other, I'll try to verify this later on this evening.