Without seeing the entire looks of the telepost and how this idea would work but I'd consider boxing in the telepost from floor to ceiling to at least the width of the QS8 and mount the 'T' bracket accordingly. It would certainly look better than having any portion of a back board or the speaker with the bracket hanging beyond the sides of the telepost.
Just exactly what is a 'telepost' anyway?
Think they may also be referred to as jackposts.
Telepost:
"A metal, upright, vertically adjustable supporting member, circular in shape, attached to a structural beam and used to level floor joists to a horizontal position."
Basically a metal pole in a basement that is used to support joists that span a long distance. If you are lucky, you can incorporate all of them in to the walls when you develop. If you are unlucky like me, you either put a telepost cover on them or box them in with on your own.
I put a telepost cover on it (as per the picture) instead of framing it in. Much easier.
There will only be about 1.5 inches of overhang on either side. Should look fine.
