D'Appolito Configuration, Contributions to DIY audio
Joseph A. D'Appolito is best known as the developer of the "D'Appolito Configuration" which was first described in his "A Geometric Approach to Eliminating Lobing Error in Multiway Loudspeakers". This configuration is recognized by loudspeakers which have two midrange or woofer drivers arranged vertically above and below the tweeter and implements the 3rd order (18dB/octave) crossover allowing the drivers to have similar horizontal dispersion, resulting in absence of any sudden change in directivity with frequency. The loudspeaker configuration is also known as a midwoofer-tweeter-midwoofer (MTM) configuration. D'Appolito is the author of "Testing Loudspeakers" and a contributing editor to AudioXpress magazine. He is also the owner of a consulting firm, Audio and Acoustics, Ltd. whose clients include Snell Acoustics; HECO/Recoton, GmbH and Usher Audio Technology.