The addons are not recommended for the type of ceiling you have. They are for flat ceilings. It would be more advisable to angle something like an on wall of the side of the beams or Axioms ceiling mounts pointed towards your MLP.
Hmmm. I thought for the add-ons, because my ceiling directly above them is flat, I would be okay? This would be the case for all .4 speakers. Dolby says ceiling should not be angled or vaulted, which mine isn't.
The bulkhead may 'interfere' with some of the sound reflected back down to the listening position, but not sure how much of an issue it would be.
My concern with the overhead set up is that if I mount under the bulkhead I don't have enough height (7ft). And if I mount just in front of (or behind) the bulkhead, well the bulkhead is in the way and I am still only at the 8ft minimum height.
