Putting geeky hat on now, sorry. I get the 9 and the 6.
Some people say the middle number is:
a. Always .1 as it is listing the number of discreet channels or
b. Say if you have Sub EQ HT, you could say it is .2 for two subwoofers based on them being a separately EQed output (and are therefore different).
c. The total number of subwoofers.
I assume you believe it is b (as anyone can separately EQ as many subs as they want) or c.
Is there a written agreed convention on this somewhere or does anyone know the answer?
P.S. I'm not being critical, I'm just wondering for when someone asks me on the forum what my setup is