Loudspeaker
A coaxial loudspeaker comprises a low frequency driver, a high frequency driver, and a magnetic circuit. The low frequency driver is configured to generate low frequency sounds and includes a first voice coil. The high frequency driver, coaxially aligned with the low frequency driver, is configured to generate high frequency sounds relative to the low frequency driver and includes a second voice coil. The magnetic circuit includes a first magnet configured to generate a first magnetic field, a second magnet configured to generate a second magnetic field, a first magnetic gap including magnetic flux from the first magnet and the second magnet in which the first voice coil is positioned, and a second magnetic gap including magnetic flux from the first magnet and the second magnet in which the second voice coil is positioned.
1. A coaxial loudspeaker comprising:
a low frequency driver configured to generate low frequency sounds, the low frequency driver including a first voice coil;
a high frequency driver coaxially aligned with the low frequency driver and configured to generate high frequency sounds relative to the low frequency driver, the high frequency driver including a second voice coil; and
a magnetic circuit shared by the low frequency driver and the high frequency driver, the magnetic circuit including
a cup including a hollow cylindrical side wall and a circular bottom wall connected to one end of the side wall,
a first magnet configured to generate a first magnetic field, the first magnet positioned within the cup in contact with the bottom wall,
a second magnet configured to generate a second magnetic field, the second magnet positioned within the cup axially spaced apart from the first magnet,
a pole piece positioned within the cup, the pole piece including a central ring and a lower flange connected to the central ring and extending radially outward, the central ring positioned radially inward from the second magnet,
a plate having a ring shape and positioned within the cup in contact with the second magnet and radially outward from the central ring,
a first magnetic gap in which the first voice coil is positioned, the first magnetic gap located between the lower flange and the side wall of the cup, and
a second magnetic gap in which the second voice coil is positioned, the second magnetic gap located between the central ring and the plate.
2. The coaxial loudspeaker of claim 1 , wherein approximately 70% of a magnetic flux generated by each magnet flows through the first magnetic gap and approximately 30% of the magnetic flux generated by each magnet flows through the second magnetic gap.
3. The coaxial loudspeaker of claim 2 , wherein the magnetic flux generated by the first magnet and the second magnet flows through the side wall, a portion of the bottom wall, the pole piece, and the plate and across the first magnetic gap and the second magnetic gap.
4. The coaxial loudspeaker of claim 1 , wherein the first magnet and the second magnet each have roughly the same shape and roughly the same dimensions.
5. The coaxial loudspeaker of claim 1 , wherein the central ring includes a flat outer surface and a rounded inner surface.
6. The coaxial loudspeaker of claim 1 , wherein the low frequency driver further includes:
a first collar on which the first voice coil is mounted,
a first diaphragm frusto-conically shaped and connected to the first collar such that motion of the first voice coil causes motion of the first diaphragm,
a first surround configured to reduce radial motion of the first diaphragm, and
a first spider configured to reduce radial motion of the first collar.
7. The coaxial loudspeaker of claim 1 , wherein the high frequency driver further includes:
a second collar on which the second voice coil is mounted,
a second diaphragm dome shaped and connected to the second collar such that motion of the second voice coil causes motion of the second diaphragm, and
a second surround configured to reduce radial motion of the second diaphragm and the second voice coil.
8. A coaxial loudspeaker comprising:
a low frequency driver configured to generate low frequency sounds, the low frequency driver including
a first voice coil,
a first collar on which the first voice coil is mounted,
a first diaphragm frusto-conically shaped and connected to the first collar such that motion of the first voice coil causes motion of the first diaphragm,
a first surround configured to reduce radial motion of the first diaphragm, and
a first spider configured to reduce radial motion of the first collar,
a high frequency driver coaxially aligned with the low frequency driver and configured to generate high frequency sounds relative to the low frequency driver, the high frequency driver including
a second voice coil,
a second collar on which the second voice coil is mounted,
a second diaphragm dome shaped and connected to the second collar such that motion of the second voice coil causes motion of the second diaphragm, and
a second surround configured to reduce radial motion of the second diaphragm and the second voice coil; and
a magnetic circuit shared by the low frequency driver and the high frequency driver, the magnetic circuit including
a cup including a hollow cylindrical side wall and a circular bottom wall connected to one end of the side wall,
a first magnet configured to generate a first magnetic field, the first magnet positioned within the cup in contact with the bottom wall,
a second magnet configured to generate a second magnetic field, the second magnet positioned within the cup axially spaced apart from the first magnet,
a pole piece positioned within the cup, the pole piece including a central ring and a lower flange connected to the central ring and extending radially outward, the central ring positioned radially inward from the second magnet,
a plate having a ring shape and positioned within the cup in contact with the second magnet and radially outward from the central ring,
a first magnetic gap in which the first voice coil is positioned, the first magnetic gap located between the lower flange and the side wall of the cup, and
a second magnetic gap in which the second voice coil is positioned, the second magnetic gap located between the central ring and the plate.
9. The coaxial loudspeaker of claim 8 , wherein approximately 70% of a magnetic flux generated by each magnet flows through the first magnetic gap and approximately 30% of the magnetic flux generated by each magnet flows through the second magnetic gap.
10. The coaxial loudspeaker of claim 9 , wherein the magnetic flux generated by the first magnet and the second magnet flows through the side wall, a portion of the bottom wall, the pole piece, and the plate.
11. The coaxial loudspeaker of claim 8 , wherein the first magnet and the second magnet each have roughly the same shape and roughly the same dimensions.
12. The coaxial loudspeaker of claim 8 , wherein the central ring includes a flat outer surface and a rounded inner surface.