A loudspeaker accessory for the production of reverberant sound

Organ music produced in small rooms having little natura1 reverberation can be enhanced by the addition of artitificial reverberation. A direct method of adding the aftersound to the electro-acoustic transducer itself is described. This is a contrast to the more conventional reverberation systems nploying driving transducers, time-delay means, pickup transducers, and mixing and amplifying circuits. Multiply resonant elical medanical delay lines store the energy and radiate it at a later time. In one model the coupling to the transducer is mechanical, .and in the other model acoustical coupling provides a number of practical and acoustical advantages.