144 



DIRECT RADIATOR LOUD SPEAKERS 



of curvature of the wave front with the distributor being considerably less 

 than that of the plain cone shows that the distributor broadens the radia- 

 tion pattern. The vertical section, Fig. 7.20C, shows that the distributor 



SECTIONAL VIEW 



A 



VERTICAL SECTION 



Fig. 7.20. High frequency sound distributors for direct radiator loud speakers. A. The 

 contour of equal phase for a plain cone. B. The horizontal cross-sectional view of a cone 

 with a vane distributor and the contour of equal phase. C. The vertical cross-sectional 

 view of a cone with a vane distributor. 



will not broaden the pattern in this direction. In general, in radio or 

 phonograph reproduction the required vertical plane of spread is quite 

 small. If a broader pattern is required in this plane crossed vanes may 

 be used. 



