Frequency-Dividing Networks
Lawrence Fleming · The Journal of the Acoustical Society of America · 1963
Where two complementary filters (crossover networks) are used for frequency-band division in sound reproduction, the sum of the outputs usually contains considerable phase distortion. Subtractive arrangements using a single filter can be made free from such distortion, but have been complicated to realize in practice. A subtractive filter is described which is simple and cheap.