Abstract: An annular suspension for supporting an acoustic diaphragm around its edge and permitting axial diaphragm movement. The suspension is made of thin folded sheet material, such as aluminum, and includes inner and outer concentric circular fold lines having a series of pyramid-like structures therebetween to control anti-nodal resonance of the suspension independently of the desired first resonance. The suspension may be formed integrally with the diaphragm, which may be of the dome or cone configuration and is provided with a conventional voice coil. The suspension permits axial diaphragm movement by slight flexing at the fold lines, minimizing stretching of the sheet material and preventing torsional movement of the diaphragm. When the suspension is at rest, the inner and outer circular fold lines desirably lie in a common plane normal to the diaphragm axis and the pyramid-like structures project alternately on each side of that plane.

Abstract: A loudspeaker horn having improving directivity has a pair of smoothly flared vertical sidewalls joined to a pair of smoothly flared horizontal sidewalls. In an exemplary embodiment, one pair of sidewalls is generated as a surface of revolution, with the curvature of the surface being defined by a power series formula. The contour of the remaining pair of sidewalls is also defined by the power series formula, although different constants may be used. The vertical and horizontal sidewalls are separately defined and are substantially congruent at the rectangular or square mouth. In the exemplary embodiment, the gap formed at the back of one of the pairs of sidewalls is connected to the throat formed at the back of the other pair of sidewalls by a connecting section having an arcuate area which monotonically increases from the throat to the gap.

Abstract: An electrical connector comprising a binding post intended to be fixed to a suitable supporting surface such as the wall of a loudspeaker enclosure, and including an outwardly extending portion provided with a camming surface disposed spirally relative to the axis of the binding post, and an operating cap of dielectric material, desirably having at least slight elastic deformability, and provided with a conductor-receiving bore extending therethrough and disposed eccentrically relative to the axis of the binding post and cap. The lower body portion of the cap has formed therein a downwardly open cavity for partially receiving the operative portions of the binding post, whereby twisting the cap through a limited angle, substantially less than 180.degree., serves to force the bared conductor within the cap into tight conductive relation with the cammed surface of the binding post.