kurn:
I have twin 10" Velodyne subs in my modest HT. These models just preceded the EQ series so are similar. When I first set the subs' amps to Volume at 4 out of 10, Audyssey's saw them as too high as its level was seen at -12 - which is off the clock too much for the room. I turned down the subs by half increments for subsequent runs of Audyssey until the Subs' Volume Levels ended up being at 2 out of 10, or about half of my original estimate. This put their level as seen by Audyssey at about -4 Db that is closer to Audyssey's ideal 0 Db.
Again, set your L & R to 'Small', AVR Xover at 80 Hz & the Sub's Xover to Full (on the sub's back panel).
It is easy to overdo it with the sub's volume that often results in boomy sound. In difficult boomy cases, room interaction might be contributing to the condition requiring a physical position change. Thankfully I didn't have to wrestle mine around the room
Mine sound great now & will make my room generate annoying sounds in the walls (metal gas fireplace & furnace ducting inside the walls) down to 20 Hz.
Hope this helps...
TAM