@conference{woolley1988miniature, title = {Miniature Direct-Radiator Subwoofer Modules}, author = {Woolley, Stephen J.}, booktitle = {Audio Engineering Society Conference: 6th International Conference: Sound Reinforcement}, month = {May}, year = {1988}, url = {https://www.aes.org/e-lib/browse.cfm?elib=4620} }