The present disclosure relates generally to acoustic panels, for example, suitable for acoustic ceiling surfaces. The present disclosure relates more particularly to acoustic panels that include a panel body (e.g., comprising fiberglass, or having an NRC value in the range of at least 0.5, e.g., 0.5-0.95 or 0.5-0.9) and a perimeter frame extending around a side edge of the panel body. The perimeter frame includes a plurality of frame members including a first frame member and a second frame member. A first adhesive bonds the frame members to the panel body. A second adhesive with a shorter working time may also bond the frame members to the panel body. In addition, or alternatively, a bracket that couples the frame members to one another includes a sharp projection that hinders removal of the bracket from the frame members once assembled. These aspects allow the acoustic panel to be handled before the first adhesive is cured.

A framed assembly includes a first frame member providing an inner vertical wall extending between opposing front and back surfaces and defining a slot, and a second frame member positioned adjacent the first frame member at a corner joint and providing a horizontal wall extending between opposing front and back surfaces of the second frame member. A clip having opposing front and back sides provides a backing plate extending from the back side and a projection extending from the front side. The backing plate is received within an interior of the first frame member via the slot, and the projection is received within an interior of the second frame member adjacent the horizontal wall.

Aspects disclosed herein relate to a fenestration supplement system and methods of using such a system. In one aspect, the fenestration supplement system includes a fenestration supplement frame member that is configured to accept three or more fenestration supplements. In another aspect, a fenestration supplement frame member has opposing first and second ends that each receives fenestration supplements, connectors and/or hardware (such as mounting hardware). In yet another aspect, a fenestration supplement frame member includes specially shaped grooves that can accept and retain different types of connectors.