CN103024641A - Loudspeaker system with backward precision annular-tube combined channel set - Google Patents

Abstract

The invention discloses a high-performance mid-bass loudspeaker system-a rear-facing precision annular tube composite channel group loudspeaker system. It installs a group of short circular tubes for radiating the sound of the speaker behind the middle and bass paper cone speakers to form a composite channel, which limits the sound radiation environment of the vibrating body and affects the vibration radiation. When the speaker works at low frequencies, its precision The annular tube composite channel is composed of an annular tube sound variable device composed of a uniform cross-sectional area ring section and a ring tube sound quality element composed of a uniform and constant cross-sectional area ring channel. Increased by the combined effect of the mass, which can reduce the low-frequency resonance frequency of the loudspeaker. The interior of the channel group is smooth and clean, which surrounds the loudspeaker in a wide range, reduces the interference of the vibrating body surface by the air vibration in the box, and the vibrating body surface is evenly loaded, which is conducive to improving the dynamic response speed, reducing distortion, and improving the medium and low frequency radiation efficiency.

Description

Rear-facing Precision Ring Tube Composite Channel Group Speaker System

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Technical field:

The present invention relates to a loudspeaker system for a composite channel group of backward precision annular tubes, which belongs to the field of electroacoustic technology.

Background technique:

In daily life, people often use loudspeakers to reproduce sound. After the commonly used electric mid-bass paper cone speakers (including bass, mid-bass, mid-range speakers and full-band speakers, hereinafter referred to as speakers) are completed, the resonance frequency ω0 of the resonance system of its low-frequency force is determined, and ω0 determines The lower limit of the sound frequency reproduced by this speaker is specified, and the speaker installed on the infinite baffle is usually used as a reference to illustrate the speaker frequency ω ₀ and other indicators. In this case, the loudspeaker placed on the infinite baffle directly radiates and transmits sound to the air in the front and back directions, where ω0=, and MM represents the total equivalent mass of the electric loudspeaker, including the cone equivalent mass M1 , the equivalent mass of the voice coil M2, the front co-vibration mass MMR1 of the vibrating body, and the back co-vibration mass MMR2, that is, MM=M1+M2+MMR1+MMR2; The gasket force follows CM2, that is, CM=.

Generally, it is not possible to use such a loudspeaker without using the baffle to reproduce the sound. In that case, the opposite-phase sound waves radiated from the front and rear directions of the loudspeaker vibrating body will be mixed in the air to cancel, and the sound reproduction ability of the loudspeaker will be lost. When in use, the loudspeaker cannot be installed on an infinite baffle for use. It is always together with the speaker, using the baffle of the speaker box to divide and limit the sound wave radiation from the front and rear of the speaker vibrating body. This is different from the speaker's reference use environment and will affect the performance of the speaker.

But when the speaker is installed on the speaker to form a speaker system, the sound energy carried by the radiated waves behind the speaker is surrounded by the box, and cannot be radiated from the box, so it cannot be directly used, and these sound waves will also be affected by the speaker box. The internal environment of the body is reflected back and forth on the vibrating body of the speaker, and the sound pressure of the reflected wave will interfere with the vibration of the vibrating body of the speaker, further affecting the ability and effect of the speaker to radiate sound, and these objects in the surrounding environment of the speaker are far away from other The closer it is, the greater the impact. The impact of the surrounding environment on the speaker radiation is reflected in the change of the total equivalent MM and CM values of the speaker, and also affects the low-frequency resonance frequency of the speaker. Therefore, the low-frequency range of the speaker's playback sound in the speaker system is determined by the speaker It is determined by two factors, and the speaker box. As far as the above formula is concerned, if the influence of the speaker box can make the total equivalent CM of the speaker at this time or the total equivalent mass MM increase, ω0 can be reduced, and the speaker can reproduce more bass.

But the reality is the opposite. Usually, when the speaker is installed on a speaker with a common structure in the traditional way of radiating sound from the front to the outside and the back to the box, it cannot effectively increase its total equivalent mass MM. On the contrary, it will always make the back of the vibrating body the same vibration mass And the total equivalent effect along the CM reduction. It can be seen from the above formula that this will make the lowest frequency of the sound reproduced by the speaker system higher than the resonance frequency ω0 of a single speaker, causing the speaker to lose some ability to reproduce low-frequency sound.

In the above cases, the reason why the speaker’s total equivalent compliance CM decreases is because the air inside the speaker constitutes a sound compliance component. When the speaker’s vibrating body works at low frequencies, it acts like an elastic spring, giving the speaker’s vibrating body a force from behind. The elastic support restricts the resonance of its vibrating body from the outside of the speaker, making it difficult for the speaker to vibrate at low frequency, and cannot push the air to radiate as much sound as before, so its low frequency resonance frequency increases. Generally, the smaller the volume of the speaker box, the greater the elasticity generated by the air in the box, and the smaller the compliance (its elastic coefficient is equal to the reciprocal of the compliance coefficient), and vice versa. The elastic effect of the sound compliance element of the box air is shown in the above calculation formula, that is, the sound compliance element at low frequencies is equivalently connected in parallel to the existing force compliance element of the speaker itself, which increases the "elasticity" of the speaker vibration body , which reduces the "compatibility" of the total equivalent force of the vibrating body along CM, resulting in an increase in its ω0. This is the case in common speaker systems, such as airtight speakers, phase-inverted speakers, and other speakers. That is, the speaker system formed by combining the traditional speaker and its usage with the traditional speaker structure cannot reduce the low frequency resonant frequency of the finished speaker during use.

Therefore, traditionally, the most common way to allow speaker systems to reproduce high-fidelity, lower-frequency sound is to use large-diameter woofers. Large-diameter woofers have a larger cone area, which can drive more air vibration radiation, and their vibrating body is heavier, which increases the total equivalent mass MM of the speaker and reduces ω0. This method of reducing the frequency of the speaker by increasing the mass of the speaker's vibrating body means that more expensive cone materials and a larger power amplifier are used to drive the speaker, and the speaker must also have a thicker voice coil to withstand the power of the amplifier. The loudspeaker also needs a larger magnet to generate a greater driving force to make it vibrate, so this method is expensive to produce and use, and more complicated to produce and debug. When using a large-diameter woofer to reproduce the midrange, the dynamic response will be slow due to the heavy vibrating body, which will affect the high-fidelity reproduction of the midrange. Large-diameter woofers and a mid-range speaker to reproduce bass and midrange, respectively, but this leads to higher cost and effort.

Moreover, usually when the ordinary mid-bass speaker is installed on the speaker box, in order to avoid the influence of the standing wave in the box on the speaker, the speaker is usually not installed in the middle of the baffle of the box. In this case, various frequencies in the box The interference imposed by the reflected wave on the back of the vibrating body is unbalanced, which also affects the load balance of the vibrating body, affects its flexible vibration, reduces the reaction speed, and the interference of the reflected wave on the vibrating body also causes vibration distortion.

The invention patent "A New Speaker System" (patent number: ZL02 2 12903.0 ) provides the sound quality in the special radiation sound transmission tube of the speaker when the speaker is working at low frequency, increases the total equivalent mass of the speaker MM, and effectively reduces the middle and low frequency. The technology of the low frequency force resonance frequency of the speaker.

"A New Type of Speaker System" is a speaker system formed by combining a mid-bass speaker and a channel formed by a sound transmission sleeve. The core work of "A New Type of Speaker System" is to install A sound tube channel is used to radiate and transfer the sound towards the back of the speaker. Since this channel is the only channel connected to the back of the speaker to radiate sound outward, the vibration radiation energy of the speaker will act on the air load between the bushings. the

In "A New Type of Loudspeaker System", when the loudspeaker works at low frequency, a narrow space from the loudspeaker to the front of the sound transmission tube forms a sound compliance component CA, and the cross-sectional area between the inner and outer round tubes sleeved on the loudspeaker is The air portion of the same annular space constitutes the acoustic mass element. At this time, from a structural point of view, "A New Type of Loudspeaker System" is mainly a composite sound structure composed of a low-frequency working loudspeaker, a sound compliance component, and a sound quality component. When the loudspeaker works at low frequencies, The sound quality of the sound quality element connected to the channel behind the speaker will become a part of the vibration quality of the speaker system. If this sound quality item is equivalently increased, the total equivalent vibration mass MM of the speaker system will increase. According to the speaker low-frequency resonant frequency formula above, it can be seen that this will reduce the low-frequency resonant frequency of the speaker, causing the speaker to radiate a lower low-frequency sound than the original. the

When "A New Type of Speaker System" is installed on the speaker box for use, since the back of the speaker vibrating body is surrounded by the sound transmission sleeve in a large area, this largely avoids the reflected sound waves of various frequencies in the box, including The standing wave directly acts on the vibrating body, which can improve the anti-interference ability of the speaker, and maintain the uniform balance of the speaker's back to the sound load, which is conducive to improving the response speed of the vibrating body. What's more important is that this kind of sound quality only exists when the speaker works at low frequency. Once the speaker leaves the low frequency and enters the mid-frequency working range, the heavy load of the sound quality in the sound transmission tube will disappear, and the speaker vibrating body can still Work normally and easily. It can be seen that this structure has also solved the problem of improving the ability to reproduce bass and the speed of reproducing midrange.

Usually, because the mid-bass music and singing voice reproduced by the speaker system rarely work continuously in the bass state for a long time in most cases, "A New Type of Speaker System" uses the sound that exists in the sound transmission sleeve channel when working at low frequencies. The method of improving the total equivalent vibration mass MM of the loudspeaker and reducing the low-frequency resonance frequency of the common mid-woofer in the finished product is of great practical significance. Compared with the usual woofer, this method saves a lot of precious materials and hardly affects The operating speed in the middle frequency range of the loudspeaker. Therefore, "A New Type of Loudspeaker System" is different from ordinary mid-bass speakers in both the method of realizing bass technology and the construction of speaker systems, and it develops the technology of mid-bass speakers. the

Through further research on "A New Type of Loudspeaker System", it is found that there are still some problems in the structure of the sound transmission channel of this loudspeaker system, which affects the performance and ability of this kind of system. It is necessary to improve and perfect it. In order to further improve the performance and functions of the system.

Because the performance and function of "A New Type of Loudspeaker System" with a radiation transfer channel is related to the structure and internal environment of its sound radiation transfer channel, according to this principle, we designed a set of speakers on the front of the speaker for transfer The forward radiating sound wave channel of the loudspeaker cone constitutes a new loudspeaker system, which is used to reduce the low-frequency resonance frequency of the loudspeaker, improve the mid- and low-frequency radiation ability of the loudspeaker, and improve the performance of the loudspeaker. Tube composite channel group speaker system . However, because the front and rear environments of the speaker are different, the group of radiation channels built on the front of the speaker is also different from the structure of the sound transmission tube channel built on the back of the speaker in "A New Type of Speaker System". Its use method and function There are also differences.

Contents of the invention

The technical problem to be solved by the present invention is to provide a rear-facing precision annular tube compound channel group loudspeaker system composed of a precision annular tube channel group and a loudspeaker to reduce the low-frequency resonance frequency of the speaker and improve the sound quality of the mid-bass , so that this system has more fidelity of the middle and low frequency sound, and improves the middle and low frequency radiation efficiency of the speaker. To overcome the defects of the existing loudspeaker system .

The technical solution adopted by the present invention to solve its technical problems is as follows:

The rear-facing precision annular tube compound channel group speaker system includes a paper cone speaker, the paper cone speaker includes a vibrating paper cone and a pot frame with a radiation port, and the front end of the pot frame side wall of the pot frame has an outer flange; The rear end of the pot frame is equipped with a circular magnet; it also includes a second inner sleeve whose front end is installed on the outer circumference of the circular magnet and is coaxial with the circular magnet; it also includes a second inner sleeve coaxial with the second inner sleeve The outer casing, the radiation port of the basin frame is located inside the outer casing; it is characterized in that it also includes at least one intermediate casing located between the outer casing and the second inner casing, the intermediate casing is coaxial with the circular magnet; the middle The front end of the casing is located in front of and close to the maximum amplitude of the vibrating paper cone; the middle casing, the outer casing and the second inner casing are connected to each other; the middle casing, the outer casing and the second inner casing are connected to each other; Form at least two annular passages between them.

It also includes a section of the first inner sleeve with the axis O of the paper cone of the vibrating body as the central axis. The rear end is aligned with the front end of the second inner sleeve, and a smooth transition surface is formed between the root of the rear end of the basin frame and the second inner sleeve.

The intersecting line between the section passing through the axis O and the outer wall on one side of the second inner casing is L1, and the intersecting line between the section and the inner wall of the outer casing on the same side as L1 is L2; Intersecting lines on the same side as L1 between the inner wall and the outer wall of the tube 12 are respectively L3 and L4; L1, L2, L3, and L4 are parallel to each other.

In the annular passage between the outer wall of the second inner sleeve and the intermediate sleeve adjacent to the second inner sleeve, a number of stoppers consistent with the direction of the annular passage are installed, or each annular passage is equipped with A plurality of barriers with the same direction of the annular channel; the barriers are solid or closed, and there is a sound transmission channel between two adjacent barriers, and each sound transmission channel has a consistent cross-sectional area along its sound transmission direction.

There is an annular space between the intermediate sleeve on the outer periphery of the first inner sleeve, the second inner sleeve and the outer sleeve; the lengths of the annular space and the annular passage are less than or equal to 1/10 of the wavelength of the low-frequency resonance sound wave of the speaker system.

The included angle between L1, L2, L3, L4 and the axis O is α=90°, and the first inner sleeve, the second inner sleeve and the outer sleeve are all annular flat plates.

Damping material is installed in the annular channel.

The positive effects of the present invention are: the speaker system of the present invention's backward precision annular tube compound channel group, through the combination of the speaker and a set of backward precision annular tube compound channel group, a new speaker system is constructed, so that the speaker, The performance is improved, the function is increased, and the usage is flexible and changeable.

1. Construct a group of precision ring tube sound variable element, and create a group of precision ring tube composite channels. the

The usual acoustic transducer is a hollow container with different inlet and outlet areas. The annular tube acoustic transducer in the speaker system of the backward precision annular tube compound channel group of the present invention is a group of acoustic transducers, which is composed of a group of adjacent inner The annular space between the outer sleeves is different from the general acoustic transducer structure, in which each annular space and the annular channel connected with it form a precision annular tube composite channel, and these precision annular tube composite channels together form a precision annular Tube composite channel group.

2. Combining the precision annular tube composite channel group with the loudspeaker, and installing it on the back of the speaker, a loudspeaker system with the back to the precision annular tube composite channel group is constructed. When the annular tube channel is a sound quality component, the annular tube in the system The equivalent sound quality of the sound quality element group can increase the total equivalent mass of the speaker, which can reduce the low-frequency resonance frequency of the speaker. There is no distortion and energy loss caused by reflective surfaces inside the tube composite channel group, which greatly improves the amplitude-frequency characteristics of the mid-low frequency output from the speaker system, making the amplitude-frequency characteristics smoother and the sound more fidelity. The internal structure of the compound channel group of the precision annular tube is regular, and the main parameters thereof can be designed very precisely, which is conducive to industrial standardized production. The back-facing precision annular tube composite channel group loudspeaker system formed by combining the precision annular tube composite channel group and the loudspeaker can further reduce the low-frequency resonance frequency of the speaker.

Usually, the ring tube sound variable converter in the innermost group of ring tube composite channels can easily obtain a larger transformation ratio. At this time, the sound quality in this channel can be used to increase the equivalent sound quality of the speaker system. Lowers the low frequency resonant frequency of the speaker.

The interior of the precision annular tube compound channel is smooth and clean, which surrounds the loudspeaker in a wide range, reducing the direct interference of the vibrating body surface by the air vibration in the box, and the vibrating body surface is evenly loaded, which is conducive to improving the dynamic response speed and reducing distortion.

What is especially important is that at this time, when all other inner and outer casing channels are a group of parallel channels, and the cross-sectional area of each annular channel itself is the same, the sound waves transmitted inside each annular channel are mainly at the front end of the channel entrance. The sound waves radiated from the ring vibration surface on the cone basin, when the radiation direction of the ring vibration surface on the cone basin is basically close to the direction of these corresponding ring channels, it can be considered that what is transmitted inside each ring channel is the plane wave radiated by the ring vibration surface , the loudspeaker system thus further improves the efficiency of radiating mid-range frequencies.

3. Improve the formation method of the sound quality components of several other main structures of the sound radiation channel, so that the structure of the loudspeaker system of the rear-facing precision annular tube composite channel group has many changes and the usage is more flexible.

In "A New Type of Loudspeaker System", when the shape of the sound tube constituting the sound transmission channel is an outwardly expanding conical shape, the annular area along the direction of the channel will change, and the sound quality element between the inner and outer tubes will no longer be the same. exist. In order to make the sound mass element still exist in the annular pipe channel at this time, it is necessary to reconstruct a space with the same cross-sectional area inside the channel along the direction of the channel as the sound mass element.

The basic composition of the ring tube sound quality element in the rear-facing precision ring tube compound channel group loudspeaker system is a section of straight circular air channel with uniform cross-sectional area and the same cross-sectional area formed between adjacent inner and outer tubes. For other needs, it can also be an annular tube channel in the shape of a truncated cone, but an acoustic mass element cannot be directly formed in this structural space, and the acoustic mass element in this channel needs to be reconfigured. For this reason, in the loudspeaker system of the composite channel group of the backward precision annular tube, the channel is further expanded and perfected when the channel is a conical annular tube channel, and even the platform of the conical annular tube channel is further expanded so that the inner and outer tube walls of the channel expand. To the plane position, it becomes a flat circular plate parallel to the inside and outside, that is, when the circular tube channel in the shape of a cone becomes a channel between two flat circular plates, the formation method of the sound mass element between the channels. The above-mentioned changes ensure that the shape and application of the composite channel of the precision annular tube are more flexible and diverse.

For this reason, the loudspeaker system of the present invention's rear-facing precision annular tube compound channel group increases several sets of barriers that are consistent with the circular tube channel in each group of sound channels, so that each group of barriers is a closed space, and the adjacent A new sound transmission channel is formed between the two sets of barriers, and each sound transmission channel has a consistent cross-sectional area along its direction. In the annular space of any, the sound quality element can be constructed simply and flexibly to meet the requirement of frequency reduction. Similarly, when the channel of the truncated circular tube becomes a channel between two flat circular plates due to the increase of the large platform of the channel, the sound mass element can also be reconfigured between the two circular plates in this way.

It can be seen that after taking these measures, the composition of the sound quality components in the channel has been expanded and improved, fundamentally ensuring that there are always sound quality components in the channel, which ensures the reduction of the force resonance frequency of the speaker system with the precision annular tube composite channel structure The function improves the ability and efficiency of the speaker to radiate mid- and low-frequency sounds. And make the choice of channel shape more flexible and free, and make its structure more widely adaptable.

4. The damping material is added in the annular tube channel to flexibly adjust the damping of the rear-facing precision annular tube compound channel group speaker system

The damping in "A New Type of Loudspeaker System" depends on three main aspects: the damping of the loudspeaker, the influence of the sound channel and the air in the box. It is not very convenient to adjust, which limits the selection of loudspeakers. In order to make more flexible use of existing loudspeakers with high and low damping values, the present invention can add damping material in the annular tube channel or at the outlet end, so as to adjust the damping of the rear-facing precision annular tube compound channel group speaker system when necessary.

5. The present invention can be directly used as a simple sound box without a sound box.

Description of drawings:

Fig. 1 is a structural schematic diagram of the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific examples.

As shown in Figure 1, the present invention includes a paper cone speaker 1, which includes a vibrating paper cone 1-2 and a pot frame 1-1 with a radiation port, the pot frame side of the pot frame 1-1 The front end of the wall is provided with an outward flanging; the rear end of the basin frame 1-1 is connected with a circular magnet 1-3. The vibration paper cone 1-2 is coaxial with the circular magnet 1-3.

Also includes the second inner casing 2 that the front end is installed on the outer circumference of the circular magnet 1-3 and coaxial with the circular magnet 1-3; also includes the outer casing 3 coaxial with the second inner casing 2, the basin The radiation port of the frame 1-1 is located inside the outer sleeve 3; it also includes at least one intermediate sleeve 12 between the outer sleeve 3 and the second inner sleeve 2, and the intermediate sleeve 12 is the same as the circular magnet 1-3. Shaft; the front end of the intermediate sleeve 12 is located in front of the maximum amplitude of the vibrating paper cone 1-2 and is close to the maximum amplitude; the intermediate sleeve 12, the outer sleeve 3 and the second inner sleeve 2 are connected to each other; the intermediate sleeve 12. At least two annular channels 4 are formed between the outer sleeve 3 and the second inner sleeve 2 .

It also includes a section of the first inner sleeve 5 with the axis O of the vibrating body paper cone 1-2 as the central axis, and the front end of the first inner sleeve 5 is airtightly connected from the root of the rear end of the pot frame 1-1 to the rear edge of the radiation port Between them, the rear end of the first inner sleeve 5 is aligned with the front end of the second inner sleeve 2 , and a smooth transition surface is formed between the root of the rear end of the frame 1 - 1 and the second inner sleeve 2 .

The intersecting line between the section passing through the axis O and the outer wall on one side of the second inner casing 2 is L1, and the intersecting line between the section and the inner wall of the outer casing 3 on the same side as L1 is L2; The intersecting lines between the inner wall and the outer wall of the intermediate sleeve 12 on the same side as L1 are respectively L3 and L4; L1, L2, L3 and L4 are parallel to each other.

In the annular passage 4 between the outer wall of the second inner sleeve 2 and the intermediate sleeve 12 adjacent to the second inner sleeve 2, several stoppers consistent with the direction of the annular passage 4 are installed, or each annular passage 4 are equipped with a number of blocking pieces that are consistent with the direction of the annular channel 4; the blocking pieces are solid or closed, and there are sound transmission channels between two adjacent blocking pieces, and each sound transmission channel is along its sound transmission direction. have a consistent cross-sectional area.

There is an annular space 10 between the intermediate sleeve 12 on the outer periphery of the first inner sleeve 5, the second inner sleeve 2 and the outer sleeve 3; the lengths of the annular space 10 and the annular passage 4 are all less than or equal to the low-frequency resonance of the speaker system 1/10 of the wavelength of sound waves.

The included angle α between L1, L2, L3, L4 and the axis O is 90°, and the first inner sleeve 5, the second inner sleeve 2 and the outer sleeve 3 are all annular flat plates.

Damping material is installed in the annular channel 4 .

How the rear-facing precision ring tube composite channel group loudspeaker system works:

In the rear-facing precision ring tube compound channel group loudspeaker system, the sound wave radiated from the back of the paper cone of the speaker vibrating body enters the annular space and is output to the outside of the channel through the outlet of the ring tube channel, so the air in the channel becomes the core of this speaker system. Partly, at any moment, the air in the channel becomes the most direct load of the vibrating body. Due to the narrow and short composite channel of the precision annular tube, when the speaker works at low frequencies, the sound pressure generated by the vibrating body can be maintained in the channel where the sound quality element is located for a period of time, so the sound pressure in the sound tube increases, and the air load in the tube has an impact on the speaker. The reaction of the vibration body is strengthened, and the rear-facing precision ring tube composite channel group speaker system produces more powerful sound radiation.

Since the inner and outer casings constituting the annular space and the annular pipe passage are all short pipes, the annular space is all short passages. That is, the precision annular tube composite channel is composed of some short tubes relative to the wavelength length of the bass to be reproduced. According to the definition, when the cross-sectional diameter and length of the annular tube channel are less than 1/10 of the wavelength of the low-frequency sound wave passing through the tube channel, the channel is a short channel. When designing, usually the cross-sectional area of the inlet and outlet of the annular space channel is different, and the cross-sectional area of the inlet and outlet of the annular tube channel is the same. At this time, the rear-facing precision annular tube composite channel group speaker system, when the speaker works at low frequency, the annular space The channel constitutes the ring tube acoustic variable element, and the ring tube channel constitutes the ring tube sound quality element.

The ring-shaped tube acoustic variable here has two functions. First, the acoustic variable can change the force impedance at both ends of the sound through its transformation ratio, that is, change the force impedance of the sound mass element acting on the speaker. Second, through the acoustic variable The variable ratio amplification effect increases the sound quality of the sound quality component to one end of the speaker equivalently, increasing the total equivalent quality of the speaker, which can reduce the low frequency resonant frequency of the speaker and improve the low frequency radiation efficiency of the speaker. Compared with "A New Type of Loudspeaker System", due to the use of this smooth annular tube channel as the sound transducer, the energy loss of the sound wave passing through the interior is greatly reduced, so that the sound transducer with this structure can be made very good. precision.

In the rear-facing precision annular tube compound channel group speaker system, the sound quality only exists when the speaker works at low frequency. Once the speaker leaves the low frequency working range, the sound quality will disappear, and the speaker vibrating body can still work normally and easily.

Take the precision annular tube compound channel group loudspeaker system composed of only two casings inside and outside as an example. In the rear facing precision annular tube compound channel group speaker system, only the friction between the air in the channel and the wall of the entire precision annular tube compound channel Loss, and since the annular space has the same friction coefficient as the channel, it is equivalent to a common sound loss element R _A2 (formed by the viscous friction between the air movement in the pipe and the pipe wall). That is to say, the rear-facing precision annular tube composite channel group loudspeaker system formed through the improvements in the above aspects has a radiation sound transmission channel that is a composite acoustic structure including an acoustic transducer, an acoustic mass element MA2, and an acoustic loss element RA2.

In the admittance type analog equivalent circuit, the ring tube acoustic transducer element and the ring tube acoustic mass element have the same volume velocity and the force-impedance transformation at both ends of the acoustic transducer, which is reflected in the parallel relationship of the two elements and the acoustic transducer The transformation ratio of the acoustic transducer, the transformation ratio S ₂ /S ₁ , reflects the force-impedance transformation of the acoustic transducer connected between the loudspeaker and the sound mass element, and will further increase the equivalent effect of the sound mass in the channel The resonating mass on the loudspeaker vibrating body.

Calculated as follows:

Assume that the outer sleeve is a round straight tube with an area of S ₁ , and S ₁ is also the effective vibration area of the loudspeaker at low frequencies. The channel of the annular tube is a straight channel with an area of S ₂ and a length of L ₂ . _{Then the} mass _of ^the _{air in the} channel _{whose area is} S2 _. The quality is proportional to the length of the channel, that is, the sound quality inside it is inversely proportional to the _S2 area, and its air quality is directly proportional to the _S2 area, which is the characteristic of the sound quality element of the ring tube, which means a smaller The sound mass in the annular pipe channel with a cross-sectional area is relatively large.

The equivalent mass of M _A0 normalized to the S ₁ plane of the loudspeaker is (S ₁ /S ₂ ) ² M _A0 , where S1/S2 is the transformation ratio of the ring tube acoustic transducer. Generally, when S ₁ is greater than S ₂ , it is easier to ensure the existence of sound quality components at low frequencies in the channel, so S ₁ is greater than S ₂ in the application, and (S ₁ /S ₂ ) ² M _A0 is greater than M _A0 at this time. That is, the equivalent sound quality of the channel converted to the loudspeaker vibrating body through the ring-shaped space sound transducer is greatly improved.

From the low-frequency resonance formula of the loudspeaker system ω0=, it can be seen that the total equivalent mass MM of the electric loudspeaker system at this time includes the equivalent mass of the cone, the equivalent mass of the voice coil, the front co-vibration mass of the vibrating body, the back co-vibration mass and the sound quality element of the ring tube The equivalent value of sound quality (S ₁ /S ₂ ) ² M _A0 , according to the characteristics of the radiation of the vibrating body in the sound tube, the entire sound tube contains the co-vibration mass MMR2 facing the back of the speaker. In practical applications, the precision ring tube composite _The channel is a short channel, so as long as the equivalent mass (S ₁ /S ₂ ) ² M _A0 of the sound quality of the ring tube sound quality channel is greater than the resonance mass M _MR2 of the loudspeaker vibrating body, the precision ring tube The total equivalent MM of the composite channel loudspeaker system increases, and at this time the resonant mass MMR2 of the original loudspeaker is included in (S ₁ /S ₂ ) ² M _A0 , that is, the total of the precision ring tube composite channel loudspeaker system The equivalent vibration mass MM=M1+M2+MMR1+(S ₁ /S ₂ ) ² M _A0 is greater than the total equivalent vibration mass MM=M1+M2+MMR1+MMR2 of the loudspeaker when there is no precision ring bushing. It can be seen that the precision ring In the tube composite channel speaker system, a value of (S ₁ /S ₂ ) ² M _A0 is added to make the low-frequency resonant frequency ω ₀ of the speaker smaller, and the system produces a lower force resonant frequency, which can radiate a lower frequency sound.

Claims (10)

1. backward accurate ring pipe composite channel group speaker system, comprise cone loudspeaker (1), described cone loudspeaker (1) involving vibrations cone (1-2) and with the basin frame (1-1) of radiation port, the basin frame sidewall front end of described basin frame (1-1) is with flanging; The rear end of described basin frame (1-1) is equipped with circular magnet (1-3); Comprise that also front end is installed on the excircle of circular magnet (1-3) and second inner sleeve (2) coaxial with circular magnet (1-3); Also comprise the outer tube (3) coaxial with the second inner sleeve (2), the radiation port of basin frame (1-1) is positioned at the inside of outer tube (3); It is characterized in that: also comprise at least one intermediate casing (12) that is positioned between outer tube (3) and the second inner sleeve (2), intermediate casing (12) is coaxial with circular magnet (1-3); The front end of intermediate casing (12) is positioned at the place ahead and close this peak swing place at vibration cone (1-2) peak swing place; Be connected to each other between intermediate casing (12), outer tube (3) and the second inner sleeve (2); Form at least bipassage ring shape passage (4) between intermediate casing (12), outer tube (3) and the second inner sleeve (2).

2. backward accurate ring pipe composite channel group speaker system according to claim 1, it is characterized in that: the first inner sleeve (5) that also comprises one section axle centered by the axes O of vibrating body cone (1-2), the airtight rear end root of basin frame (1-1) that is connected to of the front end of the first inner sleeve (5) is between the radiation port back edge, the first inner sleeve (5) rear end aligns with the second inner sleeve (2) front end and is connected, and forms level and smooth transition face between the rear end root of basin frame (1-1) and the second inner sleeve (2).

3. backward accurate ring pipe composite channel group speaker system according to claim 1 and 2, it is characterized in that: crossing the section of described axes O and the intersecting lens between the second inner sleeve (2) one side outer walls is L1, and the intersecting lens with L1 the same side between described section and outer tube (3) inwall is L2; The intersecting lens with L1 the same side between the inwall of described section and intermediate casing 12 and the outer wall is respectively L3, L4; L1, L2, L3, L4 are parallel to each other.

4. backward accurate ring pipe composite channel group speaker system according to claim 1 and 2, it is characterized in that: in the circular passage (4) between the outer wall of the second inner sleeve (2) and the intermediate casing (12) adjacent with the second inner sleeve (2), be equipped with circular passage (4) and move towards consistent several block pieces, perhaps all be equipped with in each circular passage (4) with circular passage (4) and move towards consistent several block pieces; Block piece is solid or is obturator, is transaudient passage between adjacent two block pieces, and each transaudient passage has consistent cross-sectional area along its transaudient direction.

5. backward accurate ring pipe composite channel group speaker system according to claim 3, it is characterized in that: in the circular passage (4) between the outer wall of the second inner sleeve (2) and the intermediate casing (12) adjacent with the second inner sleeve (2), be equipped with circular passage (4) and move towards consistent several block pieces, perhaps all be equipped with in each circular passage (4) with circular passage (4) and move towards consistent several block pieces; Block piece is solid or is obturator, is transaudient passage between adjacent two block pieces, and each transaudient passage has consistent cross-sectional area along its transaudient direction.

6. backward accurate ring pipe composite channel group speaker system according to claim 2 is characterized in that: be annular space (10) between the intermediate casing (12) of the first inner sleeve (5) periphery, the second inner sleeve (2) and the outer tube (3); The length of annular space (10) and described circular passage (4) all be less than or equal to speaker system the low-frequency resonant wave length of sound 1/10.

7. backward accurate ring pipe composite channel group speaker system according to claim 3 is characterized in that: be annular space (10) between the intermediate casing (12) of the first inner sleeve (5) periphery, the second inner sleeve (2) and the outer tube (3); The length of annular space (10) and described circular passage (4) all be less than or equal to speaker system the low-frequency resonant wave length of sound 1/10.

8. backward accurate ring pipe composite channel group speaker system according to claim 4 is characterized in that: be annular space (10) between the intermediate casing (12) of the first inner sleeve (5) periphery, the second inner sleeve (2) and the outer tube (3); The length of annular space (10) and described circular passage (4) all be less than or equal to speaker system the low-frequency resonant wave length of sound 1/10.

9. backward accurate ring pipe composite channel group speaker system according to claim 3, it is characterized in that: the angle α between L1, L2, L3, L4 and the axes O=90 °, it is tabular that the first inner sleeve (5), the second inner sleeve (2) and outer tube (3) are annular flat.

10. backward accurate ring pipe composite channel group speaker system according to claim 1 and 2, it is characterized in that: the circular passage is equipped with damping material in (4).

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