GB1463192A - Horn speaker - Google Patents

Abstract

1463192 Horn loudspeakers ONKYO KK 16 Jan 1974 [17 Jan 1973] 40730/76 Divided out of 1463191 Headings H4J and H4X The horn of a horn speaker (shown in simplified form in Fig. 1, having two sound passages) has for the or each sound passage a substantially straight principal axis extending therethrough. The or each passage has an inlet and a mouth parallel to one another. The cross-sectional area of the or each sound passage taken along planes perpendicular to its principal axis increases at a substantially constant rate of area expansion from the inlet plane to the mouth plane in the direction of the principal axis. The or each passage is defined by a plurality of walls 91, 92, 94, 95 (Fig. 3). Walls 91, 92 are curved and parallel to each other when considered in successive cross-sections apart from their terminations at the inlet and mouth planes (which as described are rectangular) and define between them a virtual curved surface. The centre line 93a (Fig. 2a) of this virtual curved surface substantially coincides with the substantially straight principal axis. The most direct paths on the virtual curved surface from the centre of the inlet plane to points where the virtual curved surface meets the mouth plane are virtual curved lines 93b, 93c &c. (Figs. 2b, 2c) which increase progressively in effective length as the distance of the points from the centre line increases. The other walls 94, 95 defining the or each sound passage are straight and parallel lines when considered in successive cross-sections. The curvature of the virtual curved lines progressively increase as their distance from the centre line increases. The curvature of the two walls when considered in cross-section is at a maximum at substantially the mid-portion of its principal axis (Fig. 3b). The horn may have two sound passages symmetrically disposed loudspeakers using such horns have a wide range of directivity and good low frequency reproduction.