A method of forming a box-like acoustical substrate is provided. Portions of an acoustical substrate having a decorative surface are compressed to form a flange, a first compressed region, a second compressed region, and a third compressed region. First, second, central, and third uncompressed regions are positioned respectively adjacent to the compressed regions. A left first surface and a right first surface of the acoustical substrate may be folded toward the back surface of the substrate until the second compressed region and the third compressed regions are flush with the central uncompressed region. An outer portion of the left surface may then be folded towards the back surface until the flange is flush with the right edge. The acoustical product may be used as an acoustical trap or duct. When the acoustical product is utilized as a duct, an air impermeable sheet may be positioned on the external surface.