A wall system includes a plurality of wall assemblies. The wall assembly includes a post and a wall that is rotatably supported within the post to allow for controlled extension and retraction of the wall. An edge of the wall includes a key that is received within a keyhole of an adjacent post to secure the wall in an extended position between the adjacent posts.

A sound-absorbing panel comprising a padding layer with heat-bonded synthetic fibers, wherein the padding layer has a first outer surface, a second outer surface and a first thickness, wherein the panel is made of said padding layer with no further layers of a different material between the first outer surface and the second outer surface, wherein the padding layer in at least one portion of panel has a variable density in a direction transverse to the first and second outer surfaces, the density being higher in proximity of the first and second outer layers thereof and being lower in proximity of its inner layer.

A pre-assembled internal frame for a modular wall comprises a pair of vertical frame members. Each first flange of the vertical frame member has a pair of series of vertically arranged mounting openings, and each second flange has a single series. The vertical frame members are oriented to enable the frame to be arranged in an end to end junction with another frame with adjacent vertical frame members thereof abutting. This provides three of the series of vertically arranged openings on each side of the modular wall at the end to end junction. A fastener is positioned in a fastener receiving portion for fastening the horizontal frame member to the vertical frame members. The fastener receiving portions are recessed laterally inwardly from the first and second web sections for avoiding interference between adjacent fasteners when the frame is arranged in the end to end junction with another such frame.

An assembly of extruded members including: an extruded housing member including one or more holes formed along at least one side thereof for entry of ends of one or more second extrusions therethrough; and at least one extruded aluminum clamping member including one or more pairs of opposed clamping portions for clamping the ends of the one or more second extrusions therebetween.