Patent Application
20250234134
Embodiments relate to a dual compression driver with a single, shared magnet.
Dual compression drivers include two annular diaphragms, where the diaphragms either have the same profile and work in the same frequency range or have different profiles and radiate in different frequency bands. In addition to the two diaphragms, a dual compression driver includes two motor assemblies and two phasing plugs. The phasing plugs are positioned adjacent to each other and the diaphragms radiate through two acoustic chambers that have a mutual acoustic load (waveguide or horn). Accordingly, the time delay between two exits from the adjacent phasing plugs is very small (less than a quarter wavelength at the highest frequency) and therefore it does not create interference nor a combing effect in the audio frequency range.
Comparing a dual compression driver with a regular driver having a dome diaphragm and the same diameter of the voice coil, the moving mass of each diaphragm in the dual compression driver is lower because the mass is split between the two diaphragms. Advantageously, a lower moving mass extends the high-frequency range of the dual compression driver. Having two voice coils instead of one decreases the thermal compression and increases the dynamic range and the maximum SPL (sound pressure level), because the same level of the output acoustic signal is reached at a smaller displacement of each voice coil and each diaphragm. For the same reason, the distortion at low frequencies is smaller as well in dual compression drivers compared with regular drivers. However, the disadvantage of the dual compression driver is its high cost because of the necessity to use two motor assemblies with two expensive neodymium magnets.
In one or more embodiments, a dual compression driver includes a first driver assembly including a first annular diaphragm disposed about a central axis, and a first phasing plug disposed coaxially below the first annular diaphragm and including a first plurality of apertures extending therethrough. The dual compression driver further includes a second driver assembly including a second annular diaphragm disposed about the central axis, and a second phasing plug disposed coaxially above the second annular diaphragm and including a second plurality of apertures extending therethrough. A shared annular magnet is disposed between the first driver assembly and the second driver assembly. A back cover is mounted to the first phasing plug, wherein the back cover and the first phasing plug form a first acoustic pathway for acoustic signals from the first plurality of apertures. A front adapter is mounted to the second phasing plug and has a hollow conduit formed therein along the central axis defining a circular exit of the dual compression driver, wherein the front adapter and the second phasing plug form a second acoustic pathway for acoustic signals from the second plurality of apertures. Acoustic signals from the first plurality of apertures and acoustic signals from the second plurality of apertures merge and radiate through the hollow conduit to the circular exit.
In one or more embodiments, the first driver assembly includes a first top plate disposed coaxially above the first annular diaphragm, and the second driver assembly includes a second top plate disposed coaxially below the second annular diaphragm, the shared annular magnet disposed between the first top plate and the second top plate. In one or more embodiments, the first phasing plug has a first inner edge and the second phasing plug has a second inner edge, wherein the first inner edge and the second inner edge are adjacent to each other such that the first acoustic pathway and the second acoustic pathway converge. In one or more embodiments, an output side of the first phasing plug oriented away from the first annular diaphragm includes a first plurality of radial channels extending inwardly from the first plurality of apertures to the first inner edge, and an output side of the second phasing plug oriented away from the second annular diaphragm includes a second plurality of radial channels extending inwardly from the second plurality of apertures to the second inner edge.
In one or more embodiments, the first phasing plug and the second phasing plug each have an outer portion and an inner portion joined by an intermediate portion, wherein each outer portion is generally planar, wherein each intermediate portion has an inclined section and a flat section, and wherein each inner portion is generally sloped and terminates in the first inner edge of the first phasing plug and terminates in the second inner edge of the second phasing plug. In one or more embodiments, the inner portion of the first phasing plug extends through the first annular diaphragm and the inner portion of the second phasing plug extends through the second annular diaphragm. In one or more embodiments, the first plurality of apertures are formed in the intermediate portion of the first phasing plug, and the second plurality of apertures are formed in the intermediate portion of the second phasing plug.
In one or more embodiments, the first annular diaphragm and the second annular diaphragm each have an external portion and an internal portion joined by a middle portion, wherein each external portion and each internal portion are generally planar and each first middle portion is generally sloped such that a plane of each internal portion is offset from a plane of each external portion. In one or more embodiments, the middle portion of the first annular diaphragm is aligned with the inclined section of the first phasing plug, and the middle portion of the second annular diaphragm is aligned with the inclined section of the second phasing plug. In one or more embodiments, each middle portion includes a step section configured for attaching a first voice coil to the first annular diaphragm and a second voice coil to the second annular diaphragm.
In one or more embodiments, the first plurality of apertures and the second plurality of apertures are each arranged generally circumferentially about the central axis. In one or more embodiments, the back cover has a peripheral portion and a central portion, the central portion including a hub portion extending at least partially into the hollow conduit. In one or more embodiments, a first compression chamber is defined between an input side of the first phasing plug and the first annular diaphragm, and a second compression chamber is defined between an input side of the second phasing plug and the second annular diaphragm, the first plurality of apertures forming an exit to the first compression chamber and the second plurality of apertures forming an exit to the second compression chamber.
In one or more embodiments, a dual compression driver includes a first driver assembly including a first annular diaphragm disposed about a central axis, a first phasing plug disposed coaxially below the first annular diaphragm and having a first inner edge, and a first top plate disposed coaxially above the first annular diaphragm, the first phasing plug including a first plurality of apertures extending therethrough. The dual compression driver further includes a second driver assembly including a second annular diaphragm disposed about the central axis, a second phasing plug disposed coaxially above the second annular diaphragm and having a second inner edge, and a second top plate disposed coaxially below the second annular diaphragm, the second phasing plug including a second plurality of apertures extending therethrough. A shared annular magnet is disposed between the first top plate and the second top plate. A back cover is mounted to the first phasing plug, wherein the back cover and the first phasing plug form a first acoustic pathway for acoustic signals from the first plurality of apertures. A front adapter is mounted to the second phasing plug and has a hollow conduit formed therein along the central axis and defining a circular exit of the dual compression driver, wherein the front adapter and the second phasing plug form a second acoustic pathway for acoustic signals from the second plurality of apertures. The first inner edge and the second inner edge are adjacent to each other such that the first acoustic pathway and the second acoustic pathway converge at a central bore of the dual compression driver, such that acoustic signals from the first plurality of apertures and acoustic signals from the second plurality of apertures radiate inward toward the central bore then merge and radiate through the hollow conduit to the circular exit.
In one or more embodiments, a dual compression driver includes a first driver assembly including a first annular diaphragm disposed about a central axis, and a first phasing plug disposed coaxially below the first annular diaphragm, the first phasing plug including an input side oriented toward the first annular diaphragm and an output side oriented away from the first annular diaphragm, the first phasing plug including a first plurality of apertures extending therethrough. The dual compression includes a second driver assembly including a second annular diaphragm disposed about the central axis, and a second phasing plug disposed coaxially above the second annular diaphragm, the second phasing plug including an input side oriented toward the second annular diaphragm and an output side oriented away from the second annular diaphragm, the second phasing plug including a second plurality of apertures extending therethrough. A shared annular magnet is disposed between the first driver assembly and the second driver assembly. A back cover is mounted to the first phasing plug, wherein an inner surface of the back cover and the output side of the first phasing plug form a first acoustic pathway for acoustic signals from the first plurality of apertures. A front adapter is mounted to the second phasing plug and having a hollow conduit formed therein along the central axis, the hollow conduit having a bottom end adjacent to the second phasing plug and a top end defining a circular exit of the dual compression driver, wherein an inner surface of the front adapter and the output side of the second phasing plug form a second acoustic pathway for acoustic signals from the second plurality of apertures. Acoustic signals from the first plurality of apertures and acoustic signals from the second plurality of apertures merge and radiate through the hollow conduit to the circular exit.
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
It is understood that directional identifiers such as, but not limited to, top, bottom, above, below, upper, lower, upwardly and downwardly used herein for descriptive purposes are not intended to be limiting, and are simply used to provide an exemplary environment for the components of the dual compression driver as disclosed herein. Any directional terms as used herein are merely to indicate the relative placement of various components of the dual compression driver and are not intended to limit components to any particular orientation in space.
According to one or more embodiments, a dual compression driver is disclosed herein that uses a single magnet shared between two driver assemblies. This design is scalable and helps to significantly decrease the cost of the dual compression driver by only requiring one magnet. In the single magnet configuration as disclosed herein, the phasing plugs and their corresponding diaphragms are not positioned against each other as they would be in a typical dual driver, such that the diaphragms become separated not only by the thicknesses of the phasing plugs, but by the thickness of the shared magnet and the two top plates as well. In order to prevent a delay between the phasing plug exits as well as to prevent the generation of any unwanted combing effect at high frequencies, embodiments of the dual compression driver disclosed herein minimize this time delay via a specialized configuration of the diaphragms and the phasing plugs as described below.
With reference first to
As shown in the cross-sectional view of
In one or more embodiments, the middle portion 116 includes a step section 118 configured for attaching a first voice coil 120 to the first annular diaphragm 108 and a second voice coil 122 to the second annular diaphragm 110 (
Turning now to
The first phasing plug 124 and the second phasing plug 126 may be configured to correspond to the shape of the first annular diaphragm 108 and second annular diaphragm 110, respectively. The first phasing plug 124 and the second phasing plug 126 each have an outer portion 136 and an inner portion 138 joined by an intermediate portion 140. In one or more embodiments, each outer portion 136 may be generally planar and lie in a plane orthogonal to the central axis 106. Each intermediate portion 140 has an inclined section 142 and a flat section 144. The inner portion 138 of the first phasing plug 124 is generally sloped and terminates in a first inner edge 146 and the inner portion 138 of the second phasing plug 126 is generally sloped and terminates in a second inner edge 148. The output side 130 of the first phasing plug 124 includes a first plurality of radial channels 150 extending inwardly from the first plurality of apertures 132 to the first inner edge 146, and the output side 130 of the second phasing plug 126 includes a second plurality of radial channels 152 extending inwardly from the second plurality of apertures 134 to the second inner edge 148. Each of the first and second pluralities of apertures 132, 134 is therefore acoustically connected to a corresponding one of the first and second pluralities of radial channels 150, 152. In one or more embodiments, the first plurality of apertures 132 are formed in the intermediate portion 140 of the first phasing plug 124, and the second plurality of apertures 134 are formed in the intermediate portion 140 of the second phasing plug 126.
In a compression driver, the diaphragm is loaded by a compression chamber, which is a thin layer of air separating the diaphragm from the phasing plug. In the embodiments disclosed herein, and with reference to
The first phasing plug 124 and the second phasing plug 126 are directed radially towards each other at an angle. In one or more embodiments, the middle portion 116 of the first annular diaphragm 108 is aligned with the inclined section 142 of the first phasing plug 124, and the middle portion 116 of the second annular diaphragm 110 is aligned with the inclined section 142 of the second phasing plug 126. As best shown in
With reference to
Acoustic signals created by the first annular diaphragm 108 travel through the first plurality of apertures 132 which serve as an entrance to the first phasing plug 124, and acoustic signals created by the second annular diaphragm 110 travel through the second plurality of apertures 134 which serve as an entrance to the second phasing plug 126. Accordingly, the area of the entrance to the first phasing plug 124 and to the second phasing plug 126 is significantly smaller than the area of the first annular diaphragm 108 and the second annular diaphragm 110, respectively. As illustrated in
With reference to
As shown in
As illustrated in
With reference to
In one or more embodiments, and as best illustrated in
While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.
