Speaker arrangement terminology

An output of the Ayre preamp goes to a Velodyne SMS-1 bass manager that provides acoustic room correction for a pair of HGS-15 subs. Each sub is connected via a separate balanced line, but the bass is monaural, so by russ69’s counting my setup is 6.0, with the subs being extensions of the front LR.

For surround, HDMI goes to a Bryston SP3 that returns balanced front LR to the Ayre preamp and thus uses the same subs, so still 6.0. The SP3 does have an unused LFE output, and I have a pair of spare HGS-10s it could feed. I suppose that would then be a 6.1 setup.

My plan is to use a pass through from the SMS-1 to a second SMS-1 with a long balanced line to a third HGS-15 at the other end of the room.

I was asking about conventional usage; I doubt decree applies.  I assume LFE is encoded as a separate channel, but I wonder about counting channels rather than outputs.

auxinput, your suggestion of switching the roles of the HGS-15s and HGS-10s seems rationale.  For stereo, I do enjoy the subtle vibration of pipe organ pedal notes, but IIRC the HGS-10s can deliver that, whereas the HGS-15s can make you feel pressure on your chest with a movie explosion.