With the great success of the 4320 Studio Monitor in the 1960s, the JBL management began to explore ways in which they might extend their offerings in this area. The increasing complexity of recording studio mixing consoles resulted in ever-larger physical dimensions of the electronic equipment. Effective installation of floor-standing monitor loudspeakers was not always possible or even desirable, due to the inability to locate the audio engineer beyond the near-field effect of the reproducers. What the industry needed was a compact system that could be placed either on the console bridge, control room window shelf, or suspended from the ceiling. This would leave the larger 4320 available for even more critical listening to playbacks either in the studio or the control room. The difficulty lay in developing such a modest-sized system that retained the same highly definitive, analytical character of the 4320 while accepting some small modification in low-end performance.
