horn throat การใช้

The phase plug can be considered a further narrowing of the horn throat, becoming an extension of the horn to the surface of the diaphragm.
A horn throat from the 801 penetrated the center of the LF field coil and exited into a small multicellular horn mounted in front of the LF cone.
Gunness recognized that relatively large 2-inch ( 51 mm ) horn throats, commonly used for greater SPL, produced an undesirable narrowing of the output pattern above 10 kHz.
He discovered that only half of the compression driver's energy, at best, goes directly from the diaphragm through a phase plug slot or port and into the horn throat.
This gives a pressure-to-volume velocity change ratio in the range of 8 : 1 to 10 : 1, which serves to match the impedance of the diaphragm to the horn throat.