Audio Device, and Methods for Designing and Making the Audio Devices

An audio device provided with one or more types of Helmholtz resonators, wherein each of the Helmholtz resonators includes a neck and a cavity communicating with the neck, and

• wherein at least one of the Helmholtz resonators further includes a mechanism that varies a cross-sectional shape of the neck without varying a cross-sectional area and length of the neck.

An audio device provided with a Helmholtz resonator, wherein the Helmholtz resonator includes a neck and a cavity communicating with the neck, and

• wherein any one of a plurality of types of necks is detachably attachably provided in the Helmholtz resonator, and, whereas a cross-sectional area and length of the neck are same between the plurality of types, a cross-sectional shape of the neck is different between individual ones of the types.

An audio device group comprising a plurality of types of audio devices each provided with one or more Helmholtz resonators,

• wherein, whereas a cross-sectional area and length of a neck and a volume of a cavity communicating with the neck are same between at least two of the Helmholtz resonators provided in the plurality of types of audio devices, a cross-sectional shape of the neck is different between the at least two of the Helmholtz resonators.

A method for designing a plurality of types of audio devices each provided with a plurality of Helmholtz resonators, said method comprising:

• a step of designing a cavity of each of the Helmholtz resonators individually for each of the types of audio devices, a volume of the cavity being same between the Helmholtz resonators;
• and
• a step of designing a neck, communicating with the cavity, of each of the Helmholtz resonators, wherein, whereas a cross-sectional area of the neck are same between the plurality of types of audio devices, a ratio of minimum and maximum values of distances between a center of gravity of the cross section of the neck and individual points defining an outer periphery of the cross section is differentiated between at least two of the Helmholtz resonators for each of the plurality of types of audio devices, and a difference of said ratio between said at least two of the Helmholtz resonators is differentiated between at least two of the plurality of audio devices.

A method for making a plurality of types of audio devices each provided with a plurality of Helmholtz resonators, said method comprising:

• a step of forming a cavity of each of the Helmholtz resonators individually for each of the types of audio devices, a volume of the cavity being same between the Helmholtz resonators;
• and
• a step of forming a neck, communicating with the cavity, of each of the Helmholtz resonators, wherein, whereas a cross-sectional area of the neck are same between the plurality of types of audio devices, a ratio of minimum and maximum values of distances between a center of gravity of the cross section of the neck and individual points defining an outer periphery of the cross section is differentiated between at least two of the Helmholtz resonators for each of the plurality of types of audio devices, and a difference of said ratio between said at least two of the Helmholtz resonators is differentiated between at least two of the plurality of audio devices.