The war of the phasing plugs still rages after more than 25 years. Compression driver phasing plugs have vascillated between annular rings, salt shakers, tear drops, and now radial slots again. When Bob Smith provided simple design criteria for optimization of the annular ring type, little did he realize how studiously he would be ignored. His design is now incorporated into a large compression driver capable of operating to the high frequencies where this design is important.
This paper costs $33 for non-members and is free for AES members and E-Library subscribers.