@greywolf I haven't heard the Revel, but I notice that it only has line level inputs. Maybe that works for you, but I like connecting the REL with speaker level for two channel. It also has separate line level inputs for a LFE channel if your system doubles as a home theatre line mine does. You can use both inputs simultaneously and it has separate gain controls for each.
I also noticed that the crossover frequency is shown as 50 to 150. To get my subs to blend, I'm considerably lower than 50. Not sure if that's a problem.