Phasing Plug of Compression Driver with an Improved Directivity at High Frequencies

Voishvillo A, Thony S, Nizzoli T. Phasing Plug of Compression Driver with an Improved Directivity at High Frequencies. In: Express Paper. Audio Engineering Society; 2025. Paper 384. Available from: https://aes.org/publications/elibrary-page/?id=23058

@inproceedings{Voishvillo2025_23058,
  author = {Voishvillo, Alexander and Thony, Sebastien and Nizzoli, Tommaso},
  title = {{Phasing Plug of Compression Driver with an Improved Directivity at High Frequencies}},
  note = {Paper 384},
  year = {2025},
  month = oct,
  publisher = {Audio Engineering Society},
  url = {https://aes.org/publications/elibrary-page/?id=23058}
}

TY  - CPAPER
TI  - Phasing Plug of Compression Driver with an Improved Directivity at High Frequencies
AU  - Voishvillo, Alexander
AU  - Thony, Sebastien
AU  - Nizzoli, Tommaso
M1  - Paper 384
PY  - 2025
DA  - 2025/10/14
UR  - https://aes.org/publications/elibrary-page/?id=23058
PB  - Audio Engineering Society
LA  - en
AB  - This paper seeks a solution to optimize the length of the acoustic channels in a large dome diaphragm compression drivers phasing plug, thereby forming the output wavefront and controlling directivity at high frequencies. Normally, the channels of such a driver are designed to have equal impedances. This implies equal lengths and a similar expansion ratio. This results in the assumption that the wave front should be flat at the output of the phasing plug. However, the horn cannot control the directivity of the driver at high frequencies, and it is controlled by the size of the drivers exit. To find a solution to this problem, a study on the impact of the shape of the wavefront on the directivity was performed. A convex spherical wavefront with different radii was analyzed, and directivity was modeled using the finite element analysis. The results presented in this work show that the shape of the wavefront at the exit of the compression driver can have a significant impact on the directivity at high frequencies. This solution enables the design of a large-format compression driver providing directivity control at high frequencies using a phasing plug with optimized channel lengths. An exponential horn and a constant directivity horn were used in experiments.
ER  -