Multimedia acoustics system having audio frequency digital interface

• US 9,294,843 B2
• Filed: 10/13/2008
• Issued: 03/22/2016
• Est. Priority Date: 10/13/2007
• Status: Expired due to Fees

• Current Assignee: Fan Zhang
• Original Assignee: Fan Zhang
• Inventors: Zhang, Fan
• Primary Examiner(s): Saunders, Jr., Joseph
• Assistant Examiner(s): Mooney, James
• Application Number:
  US13/124,120
• Publication Number:
  US 20120020479A1
• Time in Patent Office: 2,717 Days
• Field of Search: None
• US Class Current: 1/1
• CPC Class Codes: H04R 2209/041 Voice coil arrangements comprising more than one voice coil unit on the same bobbin
• CPC Class Codes: H04R 3/14 Cross-over networks
• CPC Class Codes: H04R 9/025 Magnetic circuit
• CPC Class Codes: H04R 9/046 Construction
• CPC Class Codes: H04R 9/06 Loudspeakers

Abstract

A multimedia acoustics system having the audio frequency digital interface, which includes at least a USB or IEEE1394 interface, a USB or IEEE1394 outlay sound card, a set of D type or T type audio frequency power amplifier and controlling circuit or MPU chip which match it, a PCB board and at least more than a pair of sound box. In every sound box configuring a full band loudspeaker and/or bandpass heavy undertone loudspeaker whose caliber is no more than 7 inches, the loudspeaker is configured a single diaphragm more magnet gaps and more loops which have resistance load characteristic or approximately resistance load characteristic, thereby form audio frequency digital multimedia acoustics system which has super high sensitivity and high fidelity quality and has 2.0 or 2.1 channel which is supplied by pc USB or IEEE1394 interface and 4.1˜7.1 channel which is supplied by single power supply.

Claims

1. A multimedia sound system with digital audio interface, comprising:

a computer or a game console having one or more interfaces comprising at least one of a Universal Serial Bus (USB) interface, an Institute of Electrical and Electronics Engineers 1394 (IEEE1394) interface, a coaxial cable interface, or a fiber-optic interface;

one or more 2.0 channel external sound cards to connect the one or more interfaces with one or more corresponding D type or T type Integrated Circuit chips (IC chips) of an audio frequency power amplifier;

a pair of channel speakers comprising a left channel speaker and a right channel speaker;

one or more control and protection circuits to protect the one or more 2.0 channel external sound cards, the audio frequency power amplifier, the one or more IC chips, and/or the pair of channel speakers, wherein;

the one or more 2.0 channel external sound cards, the one or more IC chips, one or more elements of a Surface Mount Device circuit (SMD circuit) that is coupled to the one or more IC chips, one or more elements of an integrated Complementary Metal Oxide Semiconductor circuit (“

CMOS circuit”

) that is integrated with the one or more IC chips, a Light Emitting Diode (LED) signal light to indicate working conditions of the one or more external sound cards, and/or a volume control device of the audio power amplifier are mounted on a Printed Circuit Block (PCB) or connected to the PCB through wires and connectors;

the PCB board is positioned inside the left channel speaker or on at least one support of the pair of channel speakers;

the LED signal light and the volume control device are fastened to a speaker panel of the left channel speaker or on at least one support of the pair of channel speakers;

the PCB board or a speaker panel of the left channel speaker includes a power socket that matches the one or more interfaces and connects to the computer or the game console through at least one of;

a plug of an extension cable of the one or more interfaces or directly to the one or more interfaces of the computer or the game console;

a panel of the right channel speaker is mounted with an audio frequency power socket;

an audio frequency cable connects the left channel speaker and the right channel speaker to form a 2.0 channel sound system;

each of the one or more 2.0 channel external sound cards has at least one stereo Digital to Analog Converter (DAC) of simplex 16 to approximately 48 bits;

the at least one DAC and the one or more IC chips are powered by a 5 V power supply from the one or more interfaces, and each of the at least one DAC and the one or more IC chips has a set of filtering and energy storage electrolytic capacitors that are connected in parallel and located closest to each of the respective input pins of the at least one DAC and the one or more IC chips;

a specified lower limit of a rated working voltage of the audio power amplifier is 1.1 V to approximately 2.7 V lower than a specified lower limit of a rated working voltage of the at least one DAC so that transient working voltages of the audio power amplifier and the at least one DAC do not exceed the lower limit of the rated working voltage of the audio power amplifier when 2.0 channel sound system outputs a large dynamic low audio signal of sufficiently large width;

the specified rated working voltage of the audio power amplifier is less than or equal to 5.2 VDC or DC 8-15V, and the rated continuous power of each channel of the audio power amplifier is less than or equal to 2 W;

at least one of the left channel speaker or the right channel speaker comprises at least one multi magnetic gap and at least one multi coil that each have one or more resistor loads;

the left channel speaker and/or the right channel speaker that has the at least one multi magnetic gap and the at least one multi coil is equipped with a cone-shaped or concave diaphragm that has a caliber that is less than or equal to 7 inches; and

the diaphragm of the left channel speaker and/or the right channel speaker that has the at least one multi magnetic gap and the at least one multi coil has a central hole with the diameter of 26 mm to 33 mm

such that the left channel speaker and/or the right channel speaker that has the at least one multi magnetic gap and the at least one multi coil is a full frequency band speaker having two single-point coaxial sound production, wherein an inductance generated by the multi magnetic gaps and the multi coils is offset by a phase angle of 180 degrees due to a counter electromotive force that results from a reciprocating motion.

2. The multimedia sound system of claim 1, wherein:

the at least one multi magnetic gap is a dual-magnetic gap and the at least one multi coil is a dual-coil;

the left channel speaker or the right channel speaker that has the dual-magnetic gap and the dual-coil has upper and lower polar plates that are mounted coaxially and positioned symmetrically;

each of the upper and lower polar plates is a circular panel with a central axis hole;

at least one of a round sheet magnet or a NdFeB that is magnetized and that has a polarization in a thickness direction is clamped between the upper polar plate and the lower polar plate, the magnet being matched to the upper and lower polar plates;

in terms of axial height, a ring-shaped magnetic yoke that is mounted coaxially with the upper and lower polar plates exceeds a lateral polar plane of each of the upper and lower polar plates by 0.5 to 8 mm so as to form two groups of magnetic gap circuits that are each characterized by a complete longitudinal symmetry;

an external peripheral face of the ring-shaped magnetic yoke and a vertical peripheral face of the upper and the lower polar plates constitute two coaxial ring-shaped magnetic gaps with equal diameter;

two coaxial coils of equal diameter are inserted into the ring-shaped magnetic gaps;

the two coaxial coils are made by winding one or two layers of magnetic wires;

a gap exists between the two coaxial coils;

a winding direction of the coils and a direction of current flowing through the coils are prescribed so that the two coils generate an electromotive force in a direction at a working instant;

wherein when a central axis of the upper and the lower polar plates is chosen as a vertical symmetry axis and if a bisector at one-half axial height of the magnet is chosen as a horizontal axis of symmetry, the left channel speaker or the right channel speaker that has the dual-magnetic gap and the dual-coil has a magnetic circuit marked by a bilateral and an up-down symmetry in terms of geometrical shape and magnetic property;

a cross section area, a number of turns, a coil winding depth, a coil resistance, an absolute value of an inductance of the coils, and a winding tension of each of the two coils is equal; and

while the bisector at one-half axial height of the magnet is chosen as the horizontal axis of symmetry, the left channel speaker or the right channel speaker that has the dual-magnetic gap and the dual-coil has two sets of coil circuits that have longitudinal symmetry so that a full frequency band outer-magnet speaker of dual-magnetic gaps and a dual-coil or a band-pass bass speaker marked with resistive or load characteristics is formed.

3. The multimedia sound system of claim 1, wherein:

the at least one multi magnetic gap is a dual-magnetic gap and the at least one multi coil is a dual-coil;

the left channel speaker or the right channel speaker that has the dual-magnetic gap and the dual-coil has upper and lower polar plates that are mounted coaxially and positioned symmetrically;

the upper and lower polar plates are two circular panels;

at least one of a round sheet magnet or a NdFeB magnet that is magnetized and that has a polarization in a thickness direction is clamped between the upper polar plate and the lower polar plate, the magnet being matched to the upper and lower polar plates;

in terms of axial height, a ring-shaped magnetic yoke that is mounted coaxially with the upper and lower polar plates exceeds a lateral polar plane of each of the upper and lower polar plates by 0.5 to 8 mm so as to form two groups of magnetic gap circuits that are characterized by a complete longitudinal symmetry;

an internal peripheral face of the ring-shaped magnetic yoke and a vertical peripheral face of the upper and the lower polar plates constitute two coaxial ring-shaped magnetic gaps with equal diameter;

two coaxial coils having equal diameter are inserted into the ring-shaped magnetic gaps;

the coils are made by winding one or two layers of magnetic wires;

a gap exists between the two coaxial coils;

a winding direction of the coils and a direction of current flowing through the coils are prescribed so that the two coils generate an electromotive force in a direction at a working instant;

if a central axis of the upper and the lower polar plates is chosen as a vertical symmetry axis and if a bisector at one-half axial height of the magnet is chosen as a horizontal axis of symmetry, the left channel speaker or the right channel speaker that has the dual-magnetic gap and the dual-coil has a magnetic circuit marked by a bilateral and an up-down symmetry in terms of geometrical shape and magnetic property;

a cross section area, a number of turns, a coil winding depth, a coil resistance, an absolute value of an inductance of the coils, and a winding tension of each of the two coils is equal; and

while the bisector at one-half axial height of the magnet is chosen as the horizontal axis of symmetry, the left channel speaker or the right channel speaker that has the dual-magnetic gap and the dual-coil has two sets of coil circuits that have longitudinal symmetry so that a full frequency band inner-magnet speaker of dual-magnetic gaps and dual-coil or a band-pass bass speaker is formed.

4. The multimedia sound system of claim 1, wherein:

the at least one multi magnetic gap is three magnetic gaps and the at least one multi coil is three coils

each side of a circular plate made of magnetic material is mounted with a round sheet magnet and/or a NdFeB magnet that is used for magnetizing and that has a polarization in a thickness direction;

each of the magnets has a polarity on a side of the plate close to the magnet that is the same;

three circular plates made of magnetic material are mounted separately on a lateral face of each magnet to form a pair of repulsion magnets;

the three circular plates that are mounted on each magnet are mounted coaxially, have the same projected area and match a projected plane of the two coaxially mounted magnets;

in terms of axial height, a ring-shaped magnetic yoke that is mounted coaxially with a central axis of the circular plate that has each of its sides mounted with a round sheet magnet and/or a NdFeB magnet exceeds a lateral polar plane of each side of the circular plate that has each of its sides mounted with a round sheet magnet and/or a NdFeB magnet by 0.5 to 8 mm so as to form two groups of magnetic gap circuits that are characterized by a complete longitudinal symmetry;

an internal peripheral face of the ring-shaped magnetic yoke and a vertical peripheral face of the circular plate that has each of its sides mounted with a round sheet magnet and/or a NdFeB magnet constitute three coaxial ring-shaped magnetic gaps with equal diameter;

three coaxial coils of equal diameter that each have the same cross-sectional area are inserted into the ring-shaped magnetic gaps;

the coils are made by winding one or two layers of magnetic wires;

a winding direction of the coils and a direction of current flowing through the coils are prescribed so that the three coils generate an electromotive force in a direction at a working instant,

if the central axis of the circular plate that has each its sides mounted with a round sheet magnet and/or a NdFeB magnet is chosen as a vertical symmetry axis and if a bisector at one-half axial height of the central plate is chosen as a horizontal axis of symmetry, the left channel speaker and/or the right channel speaker that has the three magnetic gaps and the three coils has a magnetic circuit that is marked by a bilateral and an up-down symmetry in terms of geometrical shape and magnetic property;

a coil resistance, a coil winding depth, an absolute value of an inductance of the coils, and a winding tension of each of the coils is equal; and

while the bisector at the one-half axial height of the central plate is chosen as the horizontal axis of symmetry, the left channel speaker and/or the right channel speaker that has the three magnetic gaps and the three coils has two sets of coil circuits that have longitudinal symmetry so that a full frequency band inner-magnet speaker of three magnetic gaps and three coils or a band-pass bass speaker is formed.

5. The multimedia sound system of claim 4, wherein:

an axis position of the three plates of the inner-magnet speaker with three magnetic gaps and three coils, and an axis position of the two magnets are equipped with central axis holes of equal projected areas;

an axis position of one or more supports of the speaker is made from a non-magnetic material;

each of the one or more supports has a central axis hole of the same projected area or a matching screw hole;

a fastener made of non-magnetic material passes through the axis hole or the matching screw hole; and

a pressure plate made of non-magnetic material that matches the plate exerts static pressure on the plate and the magnet so as to fasten them firmly at the one or more supports.

6. The multimedia sound system of claim 1, wherein:

the at least one multi magnetic gap is at least four magnetic gaps and the at least one multi coil is at least four coils;

each side of a circular plate of magnetic material is separately mounted with a round sheet magnet and/or a NdFeB magnet that is used for magnetizing and polarizing in a thickness direction;

each of the magnets has a polarity on a side of the plate close to the magnet that is the same;

at least four circular plates made of magnetic material are mounted separately on a lateral side of each magnet to form at least three pairs of repulsion magnets;

the at least four circular plates that are mounted on each magnet are mounted coaxially, have the same projected and match a projected plane of the at least three coaxially mounted magnets;

in terms of axial height, a ring-shaped magnetic yoke that is mounted coaxially with a central axis of the circular plate that has each of its sides mounted with a round sheet magnet and/or a NdFeB magnet exceeds a lateral polar plane of each side of the circular plate that has each of its sides mounted with a round sheet magnet and/or a NdFeB magnet by 0.5 to 8 mm so as to form two sets of magnetic gap circuits that are each characterized by a complete longitudinal symmetry;

an internal peripheral face of the ring-shaped magnetic yoke that is mounted coaxially with the repulsion magnets and a vertical peripheral face of the circular plate that has each of its sides mounted with a round sheet magnet and/or a NdFeB magnet constitute at least four coaxial ring-shaped magnetic gaps that each have the same equal diameter;

at least four coaxial coils having equal diameter and the same cross-sectional area are inserted into the ring-shaped magnetic gaps;

a winding direction of the coils and a direction of a current flowing through the coils are prescribed so that the coils generate electromotive force in a direction at a working instant;

if a central axis of the circular plate that has each of its sides mounted with a round sheet magnet and/or a NdFeB magnet is chosen as a vertical symmetry axis and if a bisector at one-half axial height of the central plate is chosen as a horizontal axis of symmetry, the left channel speaker and/or the right channel speaker that has the at least four magnetic gaps and the at least four coils has at least three magnetic circuits marked by a bilateral and an up-down symmetry in terms of geometrical shape and magnetic property;

when the left channel speaker and/or the right channel speaker that has the at least four magnetic gaps and the at least four coils is viewed in the lateral direction of the diaphragm, if at least half of the coils revolve in a clockwise direction, the remaining half of the coils revolve in an anticlockwise direction;

a tail end of a first coil of the at least four coils is connected in series with a head of a second coil of the at least four coils that is adjacent to the first coil of the at least four coils until all the coils of the at least four coils are connected series, wherein a tail end of a last coil of the at least four coils is connected in series with the head end of the first coil of the at least four coils to form a pair of signal input terminals of a transducer;

a cross-sectional area of each of the at least four coils is equal a winding number of each of the at least four coils is equal, a winding depth of each of the at least four coils is equal, an absolute value of a resistance of half of the at least four coils is equal to an absolute value of a resistance of the other half of the at least four coils, and an absolute value of an inductance of half of the at least four coils is to an absolute value of an inductance of the other half of the at least four coils;

a winding tension of each of the at least four coils is equal; and

while a bisector at one-half axial height of the central magnet is chosen as a horizontal axis of symmetry, the left channel speaker and/or the right channel speaker that has the at least four magnetic gaps and the at least four coils has two sets of coil circuits that have longitudinal symmetry so that a full frequency band inner-magnet speaker of at least four magnetic gaps and at least four coils or a band-pass bass speaker is formed.

7. The multimedia sound system of claim 6, wherein:

an axis position of the at least four plates of the inner-magnet speaker with at least four magnetic gaps and at least four coils, and an axis position of the at least three magnets are equipped with central axis holes of equal projected areas;

an axis position of one or more supports of the speaker is made from a non-magnetic material;

each of the one or more supports has a central axis hole of the same projected area or a matching screw hole;

a fastener made of non-magnetic material passes through the axis hole or the matching screw hole; and

a pressure plate made of non-magnetic material that matches the plate exerts static pressure on the plate and the magnet so as to fasten them firmly at the one or more supports.

8. A multimedia sound system with digital audio interfaces comprises:

a computer or game console having one or more interfaces comprising at least one of an Universal Serial Bus (USB) interface, an Institute of Electrical and Electronics Engineers 1394 (IEEE1394) interface, a coaxial cable interface, or a fiber-optic interface;

a pair of channel speakers comprising a left channel speaker and a right channel speaker;

a subwoofer;

one or more 2.1 channel external sound cards connected, by the one or more interfaces, with one or more corresponding D type or T type IC chips of a 2.1 channel audio power amplifier of the pair of channel speakers or a 2.1 channel audio amplifier of the subwoofer; and

one or more matched control and protection circuits to protect the one or more 2.1 channel external sound cards, the audio power amplifier of the pair of channel speakers, the audio amplifier of the subwoofer, the one or more IC chips, the pair of channel speakers, and/or the subwoofer, wherein;

the one or more 2.1 channel external sound cards, the one or more IC chips, one or more elements of a Surface Mount Device circuit (“

SMD circuit”

) that is coupled to the one or more IC chips, one or more elements of an integrated Complementary Metal Oxide Semiconductor circuit (“

CMOS circuit”

) that is integrated with the one or more IC chips, a LED signal light to indicate working conditions of the one or more external sound cards, a volume control device of the audio power amplifier, and/or a volume control of the heavy bass audio amplifier are mounted on a PCB board;

the PCB, the LED signal light, and the volume control devices are mounted in the subwoofer or on a panel of the subwoofer where a socket matching the one or more interfaces is mounted;

the one or more interfaces are connected to the computer or the game console via a plug of an interface extension cable;

each of a panel of the left channel speaker and a panel of the right channel speaker includes an audio jack;

each of the left channel speaker and the right channel speaker is connected to the subwoofer via an audio cable so as to make a 2.1 channel sound system;

each of the one or more 2.1 channel external sound cards has one or more 2.1 channel Digital to Analog (“

DAC”

) decoders of simplex 16 to 48 bits,

one or more signals of the pair of channel speakers are connected to the one or more IC chips of the audio power amplifier of the pair of channel speakers via the one or more DAC decoders,

one or more analog signals of the subwoofer are connected to the audio amplifier of the subwoofer via an electrical crossover with a band-pass width of 20 Hz to 250 Hz;

if the computer is a PC, the one or more DAC decoders and the audio power amplifiers of the pair of channel speakers are powered by 5 V power supply from a first USB interface of the one or more USB interfaces of the computer, while the subwoofer is powered by a 5 V power supply from a second USB interface of the one or more USB interfaces of the computer;

if the computer is a MAC, the one or more DAC decoders, the audio power amplifier of the pair of speakers, the electrical crossover, and the subwoofer are powered by the same IEEE1394 interface of the one or more interfaces with a DC 8-15 V;

each of the one or more DAC decoders and the one or more IC chips of the audio power amplifier of the pair of speakers is connected in parallel to one or more filtering and energy storage electrolytic capacitors at locations closest to the respective input pins of each of the one or more DAC decoders and the one or more IC chips;

a specified lower limit of a rated working voltage of the audio power amplifier of the pair of channel speakers is 1.1 V to 2.7 V lower than a specified lower limit of a rated working voltage of each of the one or more DAC decoders so that transient working voltages of the audio power amplifier of the pair of channel speakers and the one or more DAC decoders do not exceed the lower limit of the rated working voltage of the audio power amplifier when the 2.1 channel sound system outputs a large dynamic low audio signal of sufficiently large width;

the rated working voltage of the audio power amplifier is less than or equal to 5.25 VDC or DC 8-15V;

a rated continuous output power of each of the left channel speaker and the right channel speaker is less than or equal to 2 W;

a specified rated continuous output power of the audio amplifier of the subwoofer is less than or equal to 4 W;

the one or more IC chips of the subwoofer are connected in parallel to one or more filtering and energy storage electrolytic capacitors that are less than or equal to 1,000 μ

F to 100,000 μ

F at locations closest to the power input pins of the one or more IC chips of the subwoofer;

at least one of the left channel speaker or the right channel speaker has at least one multi magnetic gap and at least one multi coil that each have one or more resistor loads;

the left channel speaker or the right channel speaker that has the at least one multi magnetic gap and the at least one multi coil is equipped with a cone-shaped or concave diaphragm that has a caliber that is less than or equal to 7 inches;

the diaphragm of the left channel speaker or the right channel speaker that has the at least one multi magnetic gap and the at least one multi coil has a central hole with the diameter of 26 mm to 33 mm such that the left channel speaker or the right channel speaker that has the at least one multi magnetic gap and the at least one multi coil is a full frequency band speaker having two single-point coaxial sound production and a counter electromotive force that results from a reciprocating motion that is offset due to a phase angle of 180 degrees;

the subwoofer has at least one multi magnetic gap and at least one multi coil that each have one or more resistor loads;

the subwoofer having the at least one multi magnetic gap and the at least one multi coil is equipped with a cone-shaped or concave diaphragm with a caliber that is less than or equal to 7 inches; and

the diaphragm of the subwoofer having the at least one multi magnetic gap and the at least one multi coil has a central hole with the diameter of 26 mm to 33 mm such that the subwoofer that has the at least one multi magnetic gap and the at least one multi coil is a full frequency band speaker having two single-point coaxial sound production, wherein an inductance generated by the multi magnetic gaps and the multi coils is offset by a phase angle of 180 degrees due to a counter electromotive force that results from a reciprocating motion, such that a 2.1 channel digital multimedia sound system with ultra-high sensitivity and hi-fi quality and powered by the USB or the IEEE 1394 interfaces, has been formed.

9. The multimedia sound system of claim 8, wherein:

the at least one multi magnetic gap is a dual-magnetic gap and the at least one multi coil is a dual-coil;

the left channel speaker or the right channel speaker that has the dual-magnetic gap and the dual-coil has upper and lower polar plates that are mounted coaxially and positioned symmetrically;

each of the upper and lower polar plates is a circular panel with a central axis hole;

at least one of a round sheet magnet or a NdFeB magnet that is magnetized and that has a polarization in a thickness direction is clamped between the upper polar plate and the lower polar plate, the magnet being matched to the upper and lower polar plates;

in terms of axial height, a ring-shaped magnetic yoke that is mounted coaxially with the upper and lower polar plates exceeds a lateral polar plane of each of the upper and lower polar plates by 0.5 to 8 mm so as to form two groups of magnetic gap circuits that are each characterized by a complete longitudinal symmetry;

an external peripheral face of the ring-shaped magnetic yoke and a vertical peripheral face of the upper and the lower polar plates constitute two coaxial ring-shaped magnetic gaps with equal diameter;

two coaxial coils of equal diameter are inserted into the ring-shaped magnetic gaps;

the two coaxial coils are made by winding one or two layers of magnetic wires;

a gap exists between the two coaxial coils;

a winding direction of the coils and a direction of current flowing through the coils are prescribed so that the two coils generate an electromotive force in a direction at a working instant;

wherein when a central axis of the upper and the lower polar plates is chosen as a vertical symmetry axis and if a bisector at one-half axial height of the magnet is chosen as a horizontal axis of symmetry, the left channel speaker and/or the right channel speaker that has the dual-magnetic gap and the dual-coil has a magnetic circuit marked by a bilateral and an up-down symmetry in terms of geometrical shape and magnetic property;

a cross section area, a number of turns, a coil winding depth, a coil resistance, an absolute value of an inductance of the coils, and a winding tension of each of the two coils is equal; and

while the bisector at one-half axial height of the magnet is chosen as the horizontal axis of symmetry, the left channel speaker or the right channel speaker that has the dual-magnetic gap and the dual-coil has two sets of coil circuits that have longitudinal symmetry so that a full frequency band outer-magnet speaker of dual-magnetic gaps and a dual-coil or a band-pass bass speaker marked with resistive or load characteristics is formed.

10. The multimedia sound system of claim 8, wherein:

the at least one multi magnetic gap is a dual-magnetic gap and the at least one multi coil is a dual-coil;

the left channel speaker or the right channel speaker that has the dual-magnetic gap and the dual-coil has upper and lower polar plates that are mounted coaxially and positioned symmetrically;

the upper and lower polar plates are two circular panels;

at least one of a round sheet magnet or a NdFeB magnet that is magnetized and that has a polarization in a thickness direction is clamped between the upper polar plate and the lower polar plate, the magnet being matched to the upper and lower polar plates;

in terms of axial height, a ring-shaped magnetic yoke that is mounted coaxially with the upper and lower polar plates exceeds a lateral polar plane of each of the upper and lower polar plates by 0.5 to 8 mm so as to form two groups of magnetic gap circuits that are characterized by a complete longitudinal symmetry;

an internal peripheral face of the ring-shaped magnetic yoke and a vertical peripheral face of the upper and the lower polar plates constitute two coaxial ring-shaped magnetic gaps with equal diameter;

two coaxial coils having equal diameter are inserted into the ring-shaped magnetic gaps;

the two coaxial coils are made by winding one or two layers of magnetic wires;

a gap exists between the two coaxial coils;

a winding direction of the coils and a direction of current flowing through the coils are prescribed so that the two coils generate an electromotive force in a direction at a working instant;

if a central axis of the upper and the lower polar plates is chosen as a vertical symmetry axis and if a bisector at one-half axial height of the magnet is chosen as a horizontal axis of symmetry, the left channel speaker or the right channel speaker that has the dual-magnetic gap and the dual-coil has a magnetic circuit marked by a bilateral and an up-down symmetry in terms of geometrical shape and magnetic property;

a cross section area, a number of turns, a coil winding depth, a coil resistance, an absolute value of an inductance of the coils, and a winding tension of each of the two coils is equal; and

while the bisector at one-half axial height of the magnet is chosen as the horizontal axis of symmetry, the left channel speaker or the right channel speaker that has the dual-magnetic gap and the dual-coil has two sets of coil circuits that have longitudinal symmetry so that a full frequency band inner-magnet speaker of dual-magnetic gaps and dual-coil or a band-pass bass speaker is formed.

11. The multimedia sound system of claim 8, wherein:

the at least one multi magnetic gap is three magnetic gaps and the at least one multi coil is three coils

each side of a circular plate made of magnetic material is mounted with a round sheet magnet and/or a NdFeB magnet that is used for magnetizing and that has a polarization in a thickness direction;

each of the magnets has a polarity on a side of the plate close to the magnet that is the same;

three circular plates made of magnetic material are mounted separately on a lateral face of each magnet to form a pair of repulsion magnets;

the three circular plates that are mounted on each magnet are mounted coaxially, have the same projected area and match a projected plane of the two coaxially mounted magnets;

in terms of axial height, a ring-shaped magnetic yoke that is mounted coaxially with a central axis of the circular plate that has each of its sides mounted with a round sheet magnet and/or a NdFeB magnet exceeds a lateral polar plane of each side of the circular plate that has each of its sides mounted with a round sheet magnet and/or a NdFeB magnet by 0.5 to 8 mm so as to form two groups of magnetic gap circuits that are characterized by a complete longitudinal symmetry;

an internal peripheral face of the ring-shaped magnetic yoke and a vertical peripheral face of the circular plate that has each of its sides mounted with a round sheet magnet and/or a NdFeB magnet constitute three coaxial ring-shaped magnetic gaps with equal diameter;

three coaxial coils of equal diameter that each have the same cross-sectional area are inserted into the ring-shaped magnetic gaps;

the coils are made by winding one or two layers of magnetic wires;

a winding direction of the coils and a direction of current flowing through the coils are prescribed so that the three coils generate an electromotive force in a direction at a working instant,

if the central axis of the circular plate that has each its sides mounted with a round sheet magnet and/or a NdFeB magnet is chosen as a vertical symmetry axis and if a bisector at one-half axial height of the central plate is chosen as a horizontal axis of symmetry, the left channel speaker and/or the right channel speaker that has the three magnetic gaps and the three coils has a magnetic circuit that is marked by a bilateral and an up-down symmetry in terms of geometrical shape and magnetic property;

a coil resistance, a coil winding depth, an absolute value of an inductance of the coils, and a winding tension of each of the coils is equal; and

while the bisector at the one-half axial height of the central plate is chosen as the horizontal axis of symmetry, the left channel speaker and/or the right channel speaker that has the three magnetic gaps and the three coils has two sets of coil circuits that have longitudinal symmetry so that a full frequency band inner-magnet speaker of three magnetic gaps and three coils or a band-pass bass speaker is formed.

12. The multimedia sound system of claim 11, wherein:

an axis position of the three plates of the inner-magnet speaker with three magnetic gaps and three coils, and an axis position of the two magnets are equipped with central axis holes of equal projected areas;

an axis position of one or more supports of the speaker is made from a non-magnetic material;

each of the one or more supports has a central axis hole of the same projected area or a matching screw hole;

a fastener made of non-magnetic material passes through the axis hole or the matching screw hole; and

a pressure plate made of non-magnetic material that matches the plate exerts static pressure on the plate and the magnet so as to fasten them firmly at the one or more supports.

13. The multimedia sound system of claim 8, wherein:

the at least one multi magnetic gap is at least four magnetic gaps and the at least one multi coil is at least four coils;

each side of a circular plate of magnetic material is separately mounted with a round sheet magnet and/or a NdFeB magnet that is used for magnetizing and polarizing in a thickness direction;

each of the magnets has a polarity on a side of the plate close to the magnet that is the same;

at least four circular plates made of magnetic material are mounted separately on a lateral side of each magnet to form at least three pairs of repulsion magnets;

the at least four circular plates that are mounted on each magnet are mounted coaxially, have the same projected and match a projected plane of the at least three coaxially mounted magnets;

in terms of axial height, a ring-shaped magnetic yoke that is mounted coaxially with a central axis of the circular plate that has each of its sides mounted with a round sheet magnet and/or a NdFeB magnet exceeds a lateral polar plane of each side of the circular plate that has each of its sides mounted with a round sheet magnet and/or a NdFeB magnet by 0.5 to 8 mm so as to form two sets of magnetic gap circuits that are each characterized by a complete longitudinal symmetry;

an internal peripheral face of the ring-shaped magnetic yoke that is mounted coaxially with the repulsion magnets and a vertical peripheral face of the circular plate that has each of its sides mounted with a round sheet magnet and/or a NdFeB magnet constitute at least four coaxial ring-shaped magnetic gaps that each have the same equal diameter;

at least four coaxial coils having equal diameter and the same cross-sectional area are inserted into the ring-shaped magnetic gaps;

a winding direction of the coils and a direction of a current flowing through the coils are prescribed so that the coils generate electromotive force in a direction at a working instant;

if a central axis of the circular plate that has each of its sides mounted with a round sheet magnet and/or a NdFeB magnet is chosen as a vertical symmetry axis and if a bisector at one-half axial height of the central plate is chosen as a horizontal axis of symmetry, the left channel speaker and/or the right channel speaker that has the at least four magnetic gaps and the at least four coils has at least three magnetic circuits marked by a bilateral and an up-down symmetry in terms of geometrical shape and magnetic property;

when the left channel speaker and/or the right channel speaker that has the at least four magnetic gaps and the at least four coils is viewed in the lateral direction of the diaphragm, if at least half of the coils revolve in a clockwise direction, the remaining half of the coils revolve in an anticlockwise direction;

a tail end of a first coil of the at least four coils is connected in series with a head of a second coil of the at least four coils that is adjacent to the first coil of the at least four coils until all the coils of the at least four coils are connected series, wherein a tail end of a last coil of the at least four coils is connected in series with the head end of the first coil of the at least four coils to form a pair of signal input terminals of a transducer;

a cross-sectional area of each of the at least four coils is equal a winding number of each of the at least four coils is equal, a winding depth of each of the at least four coils is equal, an absolute value of a resistance of half of the at least four coils is equal to an absolute value of a resistance of the other half of the at least four coils, and an absolute value of an inductance of half of the at least four coils is to an absolute value of an inductance of the other half of the at least four coils;

a winding tension of each of the at least four coils is equal; and

while a bisector at one-half axial height of the central magnet is chosen as a horizontal axis of symmetry, the left channel speaker and/or the right channel speaker that has the at least four magnetic gaps and the at least four coils has two sets of coil circuits that have longitudinal symmetry so that a full frequency band inner-magnet speaker of at least four magnetic gaps and at least four coils or a band-pass bass speaker is formed.

14. The multimedia sound system of claim 13, wherein:

an axis position of the at least four plates of the inner-magnet speaker with at least four magnetic gaps and at least four coils, and an axis position of the at least three magnets are equipped with central axis holes of equal projected areas;

an axis position of one or more supports of the speaker is made from a non-magnetic material;

each of the one or more supports has a central axis hole of the same projected area or a matching screw hole;

a fastener made of non-magnetic material passes through the axis hole or the matching screw hole; and

a pressure plate made of non-magnetic material that matches the plate exerts static pressure on the plate and the magnet so as to fasten them firmly at the one or more supports.

15. A multimedia sound system with digital audio interfaces comprises:

a computer or game console having one or more interfaces comprising a Universal Serial Bus (“

USB”

) interface, an Institute of Electrical and Electronics Engineers 1394 (“

IEEE1394”

) interface, a coaxial cable interface, and a fiber-optic interface;

4 to 7 satellite speakers;

a subwoofer;

one or more 4.1 to 7.1 channel external sound cards connected, by the one or more interfaces, with one or more corresponding D type or T type IC chips of a 4.1 to 7.1 channel audio power amplifier of the satellite speakers and a 4.1 to 7.1 channel heavy bass audio amplifier of the subwoofer; and

one or more control and protection circuits to protect the one or more 4.1 to 7.1 channel external sound cards, the audio power amplifier of the satellite speakers, the heavy bass audio amplifier of the subwoofer, the one or more IC chips, the satellite speakers, and/or the subwoofer, wherein;

the one or more 4.1 to 7.1 channel external sound cards, the one or more IC chips, one or more elements of a Surface Mount Device circuit (“

SMD circuit”

) that is coupled to the one or more IC chips, one or more elements of an integrated Complementary Metal Oxide Semiconductor circuit (“

CMOS circuit”

) that is integrated with the one or more IC chips, a LED signal light to indicate working conditions of the one or more external sound cards, a volume control device of the audio power amplifier of the satellite speakers, and/or a volume control of the heavy bass audio amplifier of the subwoofer are mounted on a PCB board;

the PCB, the LED signal light, and the volume control devices are mounted in the subwoofer or on a panel of the subwoofer where a socket matching the one or more interfaces is mounted;

the one or more interfaces are connected to the computer or the game console via a plug of an interface extension cable;

an audio jack is on one or more panels of one or more of the 4 to 7 satellite speakers;

each of the 4 to 7 satellite speakers is connected to the subwoofer via an audio cable to make a 4.1 to 7.1 channel sound system;

each of the one or more 4.1 to 7.1 channel external sound cards has one or more 4.1 to 7.1 channel DAC decoders of simplex 16 to 48 bits,

one or more signals of the 4 to 7 satellite speakers are connected to the one or more IC chips of the audio power amplifier of the satellite speakers via the one or more DAC decoders,

one or more analog signals of the subwoofer are connected to the heavy bass audio amplifier of the subwoofer via an electrical crossover with a band-pass width of 20 Hz to 250 Hz;

the one or more 4.1 to 7.1 channel external sound cards are powered by the one or more interfaces;

the audio power amplifier of the satellite speakers, the heavy bass audio amplifier of the subwoofer, and/or the one or more control and protection circuits are independently powered by an AC/DC power supply that is built into the subwoofer;

each of the one or more DAC decoders and each of the one or more IC chips of the audio power amplifier of the satellite speakers are connected in parallel to one or more filtering and energy storage electrolytic capacitors at locations closest to the input pins of the one or more DAC decoders and the one or more IC chips so that transient working voltages of the audio power amplifier of the satellite speakers and the one or more DAC decoders do not exceed a lower limit of a rated working voltage when the 4.1 to 7.1 channel sound system outputs a dynamic low audio signal of sufficiently large width;

the rated working voltage of the audio power amplifier is less than or equal to DC 5.25V or DC 8-15V;

a rated continuous output power of audio power amplifier of the satellite speakers is less than or equal to 1 W;

a rated continuous output power of the heavy bass audio amplifier of the subwoofer is less than or equal to 4 W or 8 W;

the one or more IC chips of the subwoofer are connected in parallel to one or more filtering and energy storage electrolytic capacitors that are less than or equal to 1,000 μ

F to 100,000 μ

F at locations closest to the power input pins of the one or more IC chips of the subwoofer;

one or more of the 4 to 7 satellite speakers has at least one multi magnetic gap and at least one multi coil that each have one or more resistor loads;

the one or more of the 4 to 7 satellite speakers that has the at least one multi magnetic gap and the at least one multi coil is equipped with a cone-shaped or concave diaphragm that has a caliber that is less than or equal to 7 inches;

the diaphragm of the one or more of the 4 to 7 satellite speakers that has the at least one multi magnetic gap and the at least one multi coil has a central hole with a diameter of 26 mm to 33 mm such that the one or more of the 4 to 7 satellite speakers that has the at least one multi magnetic gap and the at least one multi coil is a full frequency band speaker having 4 to 7 single-point coaxial sound production, wherein an inductance generated by the at least one multi magnetic gap and the at least one multi coil of the one or more of the 4 to 7 satellite speakers is offset by a phase angle of 180 degrees due to a counter electromotive force that results from a reciprocating motion;

the subwoofer has at least one multi magnetic gap and at least one multi coil that each have one or more resistor loads;

the subwoofer having the at least one multi magnetic gap and the at least one multi coil is equipped with a cone-shaped or concave diaphragm with a caliber that is less than or equal to 10 inches; and

the diaphragm of the subwoofer having the at least one multi magnetic gap and the at least one multi coil has a central hole with a diameter of 26 mm to 33 mm such that the subwoofer that has the at least one multi magnetic gap and the at least one multi coil is a full frequency band speaker having one single-point coaxial sound production,

wherein an inductance generated by the at least one multi magnetic gap and the at least one multi coil of the subwoofer is offset by a phase angle of 180 degrees due to a counter electromotive force that results from a reciprocating motion.

16. The multimedia sound system with digital audio interface of claim 15, wherein:

the elements and devices of the subwoofer of the system, except for a band pass filter of the subwoofer, that can be mounted in the subwoofer are segregated from the subwoofer and used to form an independent power amplifier;

the independent power amplifier comprises at least one indicating and regulating device, at least one audio input interface, and/or at least one audio output jack mounted on the independent power amplifier panel;

a panel of one or more of the 4 to 7 satellite speakers is mounted with a first audio jack;

a panel of the subwoofer is mounted with a second audio jack; and

at least two audio cables are used to connect the independent power amplifier and the (4+1) to (7+1) speakers into the 4.1(+1) to 7.1(+1) channel digital multimedia sound system.