A phasing plug for a compression driver includes a base portion and a hub portion. The base portion includes a first side, a second side, and a plurality of apertures extending between the first and second sides. The hub portion extends from the base portion along an axis. A plurality of channels formed on the second side of the base portion, each channel extending from the hub portion to a corresponding one of a plurality of apertures extending between the first and second sides, the apertures formed to define lines cutting diagonally across the annular section.
1. A phasing plug for a compression driver, comprising:
a base portion including a first side and a second side, and an annular section defined on the first side by a first circumference and a second smaller circumference, the first and second circumferences having a common center in the base portion, where the annular section substantially overlays an annular diaphragm in an assembled compression driver;
a hub portion extending from the second side of the base portion substantially perpendicularly along an axis at the common center on the base portion;
a plurality of channels formed on the second side of the base portion, each channel extending from the hub portion to a corresponding one of a plurality of apertures defined by an open area extending between the first and second sides, the apertures formed to define lines cutting diagonally across the annular section.
2. The phasing plug of claim 1 , where the plurality of apertures include a plurality of sets of apertures, each set of apertures forming a line of apertures.
3. The phasing plug of claim 2 , where the plurality of apertures includes four sets of apertures each set forming a line of apertures arranged to cut across the annular section to form a square pattern.
4. The phasing plug of claim 2 , where the plurality of apertures include a plurality of sets of apertures each set forming a line of apertures tangential to a circle concentric with the annular section and having a smaller diameter than the annular section.
5. The phasing plug of claim 1 where the annular section includes a profile having a shape that substantially conforms to a shape of a diaphragm used in a compression driver with the phasing plug.
6. The phasing plug of claim 5 , where the shape includes either:
a V-shape to conform to a V-shaped diaphragm,
a single half roll diaphragm to conform to a single half roll diaphragm, or
a dual half roll diaphragm to conform to a dual half roll diaphragm; and
the profile includes a closed region between the first and second circumferences that substantially overlays a region of maximum displacement on the annular diaphragm in the assembled compression driver, where the open area of the apertures does not extend substantially into the closed region.
7. The phasing plug of claim 5 , where the profile has a circular apex between the first and second circumferences, and where an open area of the apertures does not extend substantially into the circular apex.
8. The phasing plug of claim 1 further comprising:
an exterior surface on the hub portion;
the exterior surface shaped to form a waveguide with an interior surface of a housing that surrounds the hub portion when the phasing plug is assembled in a compression driver.
9. The phasing plug of claim 8 where a voice coil actuates a diaphragm positioned at the annular section of the phasing plug to create sound waves through the apertures to propagate through the channels and into the waveguide formed by the interior surface of the housing that surrounds the hub portion when the phasing plug is assembled in a compression driver.
10. A compression driver comprising:
an annular diaphragm;
at least one suspension member for supporting the annular diaphragm while enabling the annular diaphragm to oscillate;
a voice coil attached to the annular diaphragm for actuating the annular diaphragm in the presence of a magnetic field;
a phasing plug comprising:
a base portion including a first side and a second side, and an annular section defined on the first side by a first circumference and a second smaller circumference, the first and second circumferences having a common center in the base portion, where the annular section substantially overlays the annular diaphragm;
a hub portion extending from the second side of the base portion substantially perpendicularly along an axis at the common center on the base portion;
a plurality of channels formed on the second side of the base portion, each channel extending from the hub portion to a corresponding one of a plurality of apertures extending between the first and second sides, the apertures formed to define lines cutting diagonally across the annular section;
the annular diaphragm being placed in substantial alignment with the annular section of the phasing plug; and
a housing positioned on the second side of the base portion, the housing having an interior surface to enclose the hub portion so as to form a waveguide with the exterior surface of the hub portion.
11. The compression driver of claim 10 , where the plurality of apertures on the phasing plug includes a plurality of sets of apertures, each set of apertures forming a line of apertures.
12. The compression driver of claim 11 , where the plurality of apertures includes four sets of apertures each set forming a line of apertures arranged to cut across the annular section to form a square pattern.
13. The compression driver of claim 11 , where the plurality of apertures include a plurality of sets of apertures each set forming a line of apertures tangential to a circle concentric with the annular section and having a smaller diameter than the annular section.
14. The compression driver of claim 10 where the annular section includes a profile having a shape that substantially conforms to a shape of a diaphragm used in a compression driver with the phasing plug.
15. The compression driver of claim 14 , where the shape of the profile includes either:
a V-shape to conform to a V-shaped diaphragm,
a single half roll diaphragm to conform to a single half roll diaphragm, or
a dual half roll diaphragm to conform to a dual half roll diaphragm; and
the profile includes a closed region between the first and second circumferences that substantially overlays a region of maximum displacement on the annular diaphragm in the assembled compression driver, where the closed region does not contain any apertures.
16. The compression driver of claim 14 , where the profile includes a circular apex between the first and second circumferences, and where the open area of the apertures does not extend substantially into the circular apex.
17. The phasing plug of claim 16 where the voice coil actuates the diaphragm to create sound waves through the apertures to propagate through the channels and into the waveguide formed by the interior surface of the housing that surrounds the hub portion when the phasing plug is assembled in a compression driver.