Horn speaker

Claim 1

A horn speaker for wide angle sound distribution comprising: a horn having a substantially straight principal horn axis and a throat and mouth in spaced parallel relation connected by two pairs of adjoined opposed side walls and a partition joining one pair of said side walls at the mid-line thereof said partition extending from the plane of said mouth toward and spaced from said throat to define a pair of sound passages, the inner surfaces of said pair of side walls joined by said partition being curved convexly inwardly from said throat to said mouth, the other pair of said side walls having a double convex inward curve, said partition increasing in cross section on opposite sides of the principal horn axis towards the side walls with which it intersects, said crossection being a maximum adjacent its side wall intersection substantially midway between said throat and said mouth, so that said sound passages increase in cross sectional area substantially uniformly from said throat to said mouth in planes normal to said principal axis, the inner surfaces of said walls and said partition being so shaped that the relationship for each sound passage is given by the equation: l = -f + √(lo + f).sup.2 + y.sup.2 wherein l is the effective length of a passage for propagating sound waves from the diaphragm to a point at a distance of y from the intersection of the principal horn axis with the mouth plane, the point being positioned on at least one first straight directional line contained in the mouth plane and passing through the intersection, lo is the length of the principal horn axis and f is a virtual focal distance: and a diaphragm connected to said horn and positioned to launch sound waves into said throat towards said mouth.