George, you need absorption. Lots of it. A suspended ceiling is the best opion, if you can accept the visual. Use enhanced acoustic tiles or white covered slabs of Fibreglass in the ceiling frame.
Carpet with acoustic underlay is the another option. The walls are another option.
Where you have two hard surfaces facing each other, parallel, you need to kill one of them. The ceiling and floor are usually the two biggest surfaces in a room.
If you are doing the walls, a chequerboard pattern is good. Panel- space- panel- space, with the opposite pattern on the opposite wall.
DD
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