On the use of operational amplifiers in loudspeaker analogs

A signal flow graph model for the vented box loudspeaker has been previously developed. [1]. Here, the signal flow graph is used to derive an analog computer circuit which will simulate the vented box loudspeaker using the operational amplifiers of a general purpose analog computer. Simulations using this model are in excellent agreement with computations made from acoustic circuit models. Scale factors are calculated for the measured electrical, mechanical, and acoustical parameters of the loudspeaker driver. The circuit with the potentiometer settings based on the scale factors was operated in real time on a Hitachi 505 general purpose computer.