HDSP - HIGH DEFINITION SOUND PROJECTION
High Definition Sound Projection
Public address loudspeakers distinguish themselves through a more or less directed radiation of a broadest possible frequency range. The purpose is to ensure that even in rooms with heavy reverberations, a sufficiently high proportion of direct sound reaches the audience, thereby enhancing audibility. Conversly, this means that such loudspeakers must be aligned very precisely in the direction of the audience in order to avoid negative effect. Due to the innovative HDSP principe of the CPD 10 and CPD 12, an almost rectangular space segmentcan be evenly covered with sound energy, provided that the speakers are correctly alligned. In particularly critical spaces, the audience should be positioned exclusively in this area.
There are two signifcant diferences in comparison to common loudspeakers: firstly, the horizontal radiation angle varies depending on the vertical angle, and secondly, the major part of the sound energy is radiated downward in a curved wavefront towards the audience, and not towards the walls or the ceiling. Sev-eral acoustic principles were combined in order to achieve this. The energy of the high-frequency driver is formed in a waveguide with varying path lengths to a vertically curved line, which is then radiated by the pre-positioned horn with a width of 120° in the lower part and 60° in the upper part. In the transition to the low-mid frequency membrane, the sound signal is electronically delayed and phase corrected in such a way that the main inclined radiation axis is sustained over a wide frequency range. Likewise, the crossover frequency is selected in a way that the bundling resulting from the diameter of the membrane is equiva-lent to that of the mid-high frequency horn.
As a result, the CPD10 and CPD12 impress with an even and well-balanced sound pressure distribution both in the width and depth of space. Audibility is increased in a surprising way due to the small proportion of difuse ambience. In most cases, there is no necessity to use diferent speakers in the short and long range, whereby a problematic transition range does not occur. This allows to reduce costs and the required installation volume in the installation area.