Is Phase Linearization of Loudspeaker Crossover Networks Possible by Time Offset and Equalization?

Vanderkooy J, Lipshitz SP. Is Phase Linearization of Loudspeaker Crossover Networks Possible by Time Offset and Equalization? J Audio Eng Soc. 1984;32(12):946-955. Available from: https://aes.org/publications/elibrary-page/?id=4468

@article{Vanderkooy1984_4468,
  author = {Vanderkooy, John and Lipshitz, Stanley P.},
  title = {{Is Phase Linearization of Loudspeaker Crossover Networks Possible by Time Offset and Equalization?}},
  journal = {Journal of the Audio Engineering Society},
  volume = {32},
  number = {12},
  pages = {946--955},
  year = {1984},
  month = dec,
  publisher = {Audio Engineering Society},
  url = {https://aes.org/publications/elibrary-page/?id=4468}
}

TY  - JOUR
TI  - Is Phase Linearization of Loudspeaker Crossover Networks Possible by Time Offset and Equalization?
AU  - Vanderkooy, John
AU  - Lipshitz, Stanley P.
T2  - Journal of the Audio Engineering Society
J2  - J. Audio Eng. Soc.
VL  - 32
IS  - 12
SP  - 946
EP  - 955
PY  - 1984
DA  - 1984/12/06
UR  - https://aes.org/publications/elibrary-page/?id=4468
PB  - Audio Engineering Society
LA  - en
AB  - Conventional loudspeaker crossover networks of slope greater than 6 dB per octave, when properly implemented, result in a loudspeaker system whose acoustic transfer function, although of flat magnitude, has all-pass phase characteristics. The system is thus nonminimum phase, and complicated phase equalization using delay equalizers is required in order to render it linear phase and so transient perfect. A number of attempts are currently being made to "acoustically align" such systems by deliberately either introducing or eliminating time delays between the drivers and using conventional minimum-phase equalization to flatten their overall frequency response. It is shown that no choice of interunit time delay can render the system minimum phase, and hence that minimum-phase equalization cannot make such a system both flat and phase linear.
ER  -