Abstract: An acoustic core may include an array of resonant cells configured as a plurality of resonant cell groups. The resonant cell groups may include a plurality of resonant cells configured as a partitioned resonant cell that include a converging resonant cell and a diverging resonant cell. The converging resonant cell and the diverging resonant cell may be defined by a plurality of cell walls integrally formed with one another and a partition integrally formed with the plurality of cell walls. The partition may at least partially delimit the converging resonant cell from the diverging resonant cell. The converging resonant cell may define an upper resonant space delimited by the partition and a top face of the array of resonant cells. The diverging resonant cell may define a lower resonant space delimited by the partition and a bottom face of the array of resonant cells.

Abstract: A cabinet maker's arch door or crown door marking gauge has side members attachable to a work table of a table saw or shaper. A spring band is held on the side members so that opposite sides of the band are perpendicular to the sides of a panel to be marked which is positioned between the side members. The band forms a symmetrical arch between the sde members which is marked on the panel. One side of the band is adjustably held by one side member so the length of the band between the side members, and thus the height of the arch between the side members can be varied. The side member are adjustably held on the support so the distance between the side members can be changed to permit marking panels of different widths.