Acoustics of Plywood/drop ceiling

[Anomaly Design]

Can anyone give me some kind of insight on how plywood walls and an arched drop ceiling will affect my acoustics? I would assume the plywood would do alot of deflecting and my drop ceiling would do alot of absorbing/diffusion. its a 20'x12' room with uneven brick flooring. 5 ply-wood, the drop ceiling pieces hang protrude the surface of the ceiling (it drops down 1/2 inch lower between beam if that makes sense, aka the surface is uneven between pieces).
___
My ceiling is shaped like this: / \
Without those spaces between lines

 

[Ethan Winer]

> how plywood walls and an arched drop ceiling will affect my acoustics? <

Arches and peaks are not good because they focus the sound to a line directly under the center. This photo show how I placed absorbers under the peak in my home studio:

--Ethan

 

[Track Rat]

The ceilings in my studio are oxboard which is like a coarse pressboard. My ceilings are low but I'm not having any problems from them. The rest of the walls are treated however.