Phase Plug: Rent Com Inc: Audio Visual, Video, Projection, Presentation Rental AV Equipment

Phase Plug

In a compression driver, the sound radiating area of the diaphragm is much larger than the throat area of the horn. The sound from the diaphragm area must be collected and "compressed" down to the size of the horn throat while maintaining the complex phase relationships of the program material. The phase plug performs this function, and its design is critical to the fidelity of the transducer.

By careful design, the resonant cavity formed by this phase plug can be used to actually boost the driver's response over some narrow band of frequencies. The price paid is that the high-frequency response falls off much faster above the frequency of resonance, and that radical phase shift occurs over a very narrow band. The M4 does not resonate this cavity, and as a result exhibits a more natural response in the critical articulation region surrounding 2kHz.