Introduction to distributed mode loudspeakers (DML) with first-order behavioural modelling

A simple equivalent circuit of a distributed mode loudspeaker (DML) is described, which is accessible to engineers not specialised in acoustics. The DML is an acoustic radiator, the electrical, mechanical and acoustical properties of which differ radically from conventional moving coil transducers. DML radiation results from uniformly distributed, free vibration in a stiff light panel and not pistonic motion. To enable acoustic engineers to use existing software programs to model their application of DML technology, an efficient equivalent circuit is developed. Within the constraints of the model, velocities and displacements of the various elements can be calculated, and the radiated acoustic power and pressure predicted