Abstract: An improved speaker enclosure apparatus re-radiates biphase sound emanating from a speaker supported therein. When connected to receive a differential sound signal, the sound produced complements the direct sound radiating from "right" and "left" speakers. The enclosure is of compliant material, such that at low frequencies the entire enclosure expands and contracts with the expansion and contraction of the speaker diaphragm, responsive to volume expansion and contraction of the air enclosed in the enclosure. At high frequencies, only thinned portions of the enclosure expand and contract, responsive to the higher frequency sound wavefronts emanating from the speaker. The ability to mold the enclosure and the thinned portions provides a method of controlling the radiated wavefront to a desired shape to be propagated into the listening environment.

Abstract: An apparatus for applying an adhesive to the back of a book has a compressing plate inclined at an angle with respect to horizontal to provide a gap between the plate and book surface which converges in the direction the book travels whereby the adhesive layer is gradually compressed and pressed into the back of the book.