Analysis of loudspeakers directivity diagram versus frequency and impact to sound systems effectiveness

The directivity diagram of loudspeakers is important parameter when acoustic engineer starts to design loudspeakers grid used in masking or public address systems. The key factor when we talking about closed premises is the placement of the loudspeakers and his directivity pattern. That is why during the early 1960s many researches were made by companies like JBL and TOA at loudspeaker directivity pattern. The aim was to create wide band loudspeakers to respond the sound masking systems wide spectrum that also has enough acoustic power to cover maximum floor area and to create homogeneously sound ambiance. This will alleviate the engineer design and the total quantity of the speakers which will make the entire system less complex and more effective. Now in this topic we will check and examine the directivity pattern of three types of loudspeakers according to the generated frequencies from sound masking systems. The most common methods to obtain the frequency response and directivity pattern are Swept Sine method, MLS method and RTA method. We are going to use the RTA (Real time analyzer) method, which gives practical results in real acoustic ambiance.