Acoustic filter for a coaxial electro-acoustic transducer
AssigneeBlueprint Acoustics Pty Ltd
InventorZeljko Velican
Life of this patent
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Abstract
An acoustic filter suitable for an electro-acoustic transducer includes a relatively high frequency driver and a relatively low frequency driver situated on a common axis. The acoustic filter includes a baffle body having an outer side and an inner side, such that the outer side serves as a baffle for the high frequency driver. The inner side forms a first wall of a Helmholtz resonator including a chamber and a vent duct communicating with the chamber.
Claims11
An acoustic filter suitable for an electro-acoustic transducer having a relatively high frequency driver and a relatively low frequency driver situated on a common axis, said acoustic filter comprising:
- a baffle body having an outer side and an inner side, such that said outer side serves as a baffle for said high frequency driver and said inner side forms a first wall of at least one Helmholtz resonator including a chamber and a vent duct communicating with said chamber wherein the baffle body is arranged to convert low end response of the high frequency driver to half space radiation (2 pi steradian);
- wherein said Helmholtz resonator acts with said baffle body to provide an acoustic crossover between said drivers, and wherein said Helmholtz resonator is adapted to boost output of said low frequency driver above piston range both on-axis and off-axis to provide a response perceived by a listener to be substantially flat over a wide range of listening angles;
- and
- wherein said low frequency driver includes a cone and wherein said cone forms a second wall of said Helmholtz resonator.
A method of acoustically filtering an electro-acoustic transducer having a relatively high frequency driver and a relatively low frequency driver situated on a common axis to form an acoustic crossover between said drivers, said method comprising:
- forming a baffle body having an outer side and an inner side, such that said outer side acts as a baffle for said high frequency driver and said inner side forms a first wall of at least one Helmholtz resonator including a chamber and a vent duct communicating with said chamber wherein the baffle body is arranged to convert low end response of the high frequency driver to half space radiation (2 pi steradian);
- wherein said Helmholtz resonator acts with said baffle body to provide an acoustic crossover between said drivers;
- adapting said Helmholtz resonator to boost output of said low frequency driver above piston range both on-axis and off-axis to provide a response perceived by a listener to be substantially flat over a wide range of listening angles;
- and
- wherein said low frequency driver includes a cone and wherein said cone forms a second wall of said Helmholtz resonator.
Dependencies are inferred from the claim text.