Patent Application
20250080890
Embodiments of the present invention generally relate to a microphone capsule assembly and a microphone system.
Condenser microphones convert acoustic signals into electrical signals. They are generally more sensitive to vibrations and other external dynamic motion effects than other types of microphones, such as voice coil based dynamic microphones, and they can detect more nuances in the acoustic signal. This sensitivity makes them well-suited for recording vocals and acoustic instruments.
The general structure of a condenser microphone consists of a capsule and a mounting. The capsule includes a diaphragm, a back-plate, and circuitry to convert the acoustic signals into electrical signals. The condenser microphone is typically able to detect acoustic signals using a polar pattern, such that the microphone is able to detect sound from different directions. Condenser microphones typically have a cardioid polar pattern, meaning they are most sensitive to acoustic signals received from the front of the microphone and reject acoustic signals from the rear. The mounting allows the microphone to be attached to a stand, a boom arm, or directly to a sound recording device.
Suspension systems are used in condenser microphones to isolate the capsule from mechanical vibrations. Mechanical vibrations and dynamic motion effects, such as physical impacts on the microphone body, can cause the diaphragm to vibrate and introduce unwanted noise into the audio signal. However, current suspension systems are bulky, adding weight and size to the microphone, absorb some of the sound waves that hit the diaphragm, and often include unwanted resonant frequencies disposed within an audible range of a human's hearing.
Accordingly, there is a need for a suspension system for a condenser microphone that solves the problems described above.
Embodiments of the present invention generally relate to a microphone capsule assembly and a microphone system.
In an embodiment, a microphone capsule suspension assembly is provided. The microphone capsule suspension assembly includes a capsule mount configured to support a microphone capsule, and a pair of mounting arms. The pair of mounting arms include a first mounting arm and a second mounting arm, where the first mounting arm includes a first end, a second end and a central portion disposed between the first end and the second end. The second mounting arm includes a third end, a fourth end and a central portion disposed between the third end and the fourth end. The capsule mount is coupled to, and disposed between, the central portions of the first mounting arm and the second mounting arm. The first end, second end, third end, and fourth end each include a clamping structure. The clamping structures are each configured to be supported by a portion of a housing that supports the microphone capsule suspension assembly.
In another embodiment, a microphone assembly is provided. The microphone assembly includes a microphone capsule suspension assembly. The microphone capsule assembly includes a capsule mount that has a capsule mount body configured to support a microphone capsule, a first mounting arm coupled to a first portion of the capsule mount body disposed on a first side of the capsule mount body, and a second mounting arm coupled to a second portion of the capsule mount body disposed on a second side of the capsule mount body. The microphone capsule assembly further includes a first clamping structure disposed on a first end of the first mounting arm, a second clamping structure disposed on a second end of the first mounting arm, a third clamping structure disposed on a first end of the second mounting arm, and a fourth clamping structure disposed on a second end of the second mounting arm.
In yet another embodiment, a microphone capsule suspension assembly is provided. The microphone capsule suspension assembly includes a capsule mount configured to support a microphone capsule, and a plurality of mounting arms. The plurality of mounting arms include a first mounting arm and a second mounting arm. The first mounting arm includes a first end and a first central portion, the second mounting arm includes a second end and a second central portion. The capsule mount is coupled to the first central portion of the first mounting arm and the second central portion of the second mounting arm. The first end of the first mounting arm and the second end of the second mounting arm each include a clamping structure, each configured to be supported by a portion of a housing that supports the microphone capsule suspension assembly.
So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, may admit to other equally effective embodiments.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.
Embodiments herein are generally directed to a microphone assembly and a microphone system that is configured to support a condenser microphone during use. More particularly, to systems and methods for improved support structures, e.g., suspensions, for use with condenser microphones.
Suspensions are used within a condenser microphone to isolate the condenser microphone capsule from mechanical vibrations and physical impacts imparted on the microphone assembly. Mechanical vibrations and physical impacts on the body of the microphone assembly can cause the supporting structure and microphone diaphragm to vibrate, which can introduce unwanted noise into the audio signal. The amount of generated noise can be especially undesirable where the structure that supports the condenser microphone capsule includes a resonant frequency that is within the audible range of the sound that the condenser microphone capsule is intended to capture during use. Suspensions are often made of a soft and flexible material, and are placed between the capsule and the supporting structure of the microphone housing. This allows the suspension to support and absorb mechanical vibrations and physical impacts received by and transmitted through the microphone housing. Suspensions may be external or internal. External suspensions are mounted on the outside of the microphone housing, and they are typically made of a thicker material, which may be costlier and bulkier. Internal suspensions are mounted inside the microphone housing, and they are typically made of a thinner material.
However, conventional suspensions are bulky, adding weight and size to the microphone, absorb some of the sound waves that hit the diaphragm, and often include unwanted resonant frequencies disposed within an audible range of a human's hearing, and thus produce undesirable frequency responses to sounds received in parts of the audible range. In general, resonant frequencies of a simple mechanical structure can be determined by:
where “k” is the spring constant (e.g., stiffness of the supporting system) and “m” is the mass of the vibrating portion of the supporting system, such as the capsule and a portion of its supporting structure. This is known as the suspended resonance frequency. Frequencies greater than this suspended resonance frequency are known as the mass controlled region, and are characterized by a high degree of isolation between the capsule and supporting structure. In contrast, frequencies lower than the suspended resonance are known as the stiffness controlled region, and are characterized by a low degree of isolation between the capsule and supporting structure. Since the mass (m) of the a condenser microphone capsule is typically small, the suspended resonant frequencies of most condenser microphone containing systems that utilize condenser microphone will be higher in the audible frequency range versus a voice coil (e.g., dynamic diaphragm microphones) type of microphones assembly, due to the larger mass of the diaphragm coupled components in the voice coil microphone designs, such as the voice coils themselves and related magnets required to allow the voice coil microphones to function. As a result of the low capsule mass, to achieve a high degree of isolation so that the device is resistant to external vibrations, it is necessary to have suspension with a very low stiffness. There are some important considerations in this design: First, it must offer low stiffness axially, but high stiffness laterally. This is needed to allow good isolation in the direction of diaphragm motion, where the capsule is extremely sensitive to motion, while preventing tilting, rocking, or other unstable motion that might cause collisions with nearby internal structures.
In some embodiments of the disclosure herein, it is desirable to design the suspension structure so that any developed resonant frequencies are less than 100 hertz (Hz), since the audible range of most human voices is greater than 100 Hz. In one example, the suspension structure is designed so that it has a desirable structural shape, as disclosed herein, and is formed from a material that it adapted to prevent the formation of resonant frequencies in the suspension structure that are greater than 100 Hz, or in resonant frequencies that are greater than 80 Hz, or in resonant frequencies that are greater than 40 Hz, even in resonant frequencies that are greater than 20 Hz. In some embodiments, the suspension structure disclosed herein is less stiff than conventional microphone capsule designs and utilizes materials that have higher damping coefficients so that a better sound quality can be provided as a signal output by the microphone assembly.
To address these issues, the present disclosure provides a support structure for a condenser microphone including a suspension mounted to a clamp assembly. The suspension includes a pair of mounting arms with a clamping structure disposed on the respective ends of each of the mounting arms of the suspension. In some embodiments, the clamping structures are angled in a symmetrical, mirrored fashion along an x-axis and a y-axis such that each clamping structure is a mirror of the adjacent clamping structure. Further, the mounting arms are each configured to have a stiffness that allows for flexibility of the suspension to support the microphone capsule while improving its effective damping of vibrations received from the microphone housing to the microphone capsule. The vibrations received by the microphone capsule causes oscillations in the diaphragm of the microphone capsule, which are picked up by the signal detection components (e.g., diaphragm movement detection components) of the microphone capsule, and thus cause distortion at one or more frequencies in the sound detected by the microphone.
The microphone housing 102 may be connected to an external controller (not shown) via a controller cable 110. The controller cable may simultaneously provide power to the condenser microphone assembly 100 and provide various electrical signals to the controller, such as a signal from the microphone capsule that includes information relating to sound detected over an audible range. In some embodiments, the audible range that can be detected by the microphone capsule includes frequencies between about 20 Hz and 20,000 Hz, such as frequencies between about 80 Hz and 16,000 Hz.
The second mounting arm 220b is configured similarly with a third mounting arm bend 226 disposed on one end of the second mounting arm 220b and coupled to a third clamping structure 236 disposed adjacent to the third mounting arm bend 226 and a fourth mounting arm bend 228 on an opposing end of the second mounting arm 220b and coupled to the fourth clamping structure 238 disposed adjacent to the fourth mounting arm bend 228. A central region of the second mounting arm 220b is disposed between the third mounting arm bend 226 and the fourth mounting arm bend 228.
As shown in
In one embodiment, as illustrated in
In
In some embodiments, each of the first mounting arm 220a and the second mounting arm 220b may be made of a material having a Shore A hardness of between about 20 and 50, such as about 30 and 40, and preferably about 35. A hardness in these ranges allows for the first mounting arm 220a and the second mounting arm 220b to be taught enough to support and secure a capsule in a microphone assembly while soft enough to provide effective dampening through the microphone capsule suspension assembly 200. For example, the material may be butyl rubber. However, in some cases the material may be a polyurethane or a silicone. The capsule mount is made of a material having a Shore A hardness of between about 30 and about 40, and preferably about 35. The capsule mount 210 may also be made of the same or similar materials as the pair of mounting arms 220. For example, the capsule mount 210 and the pair of mounting arms 220 may be a single piece. Alternatively, the capsule mount 210 may be made of a different material than then pair of mounting arms 220 and could be bonded to the pair of mounting arms 220.
In one embodiment, the material used to form the microphone capsule suspension assembly 200 includes a material that has a tensile modulus (Young's modulus) of between about 7.5 megapascals (MPa) and about 12 MPa. In some embodiments, the material used to form the microphone capsule suspension assembly 200 includes a material that has a loss factor η of between about 0.5 and about 5. In one embodiment, the material used to form the microphone capsule suspension assembly 200 includes a material that has a glass transition temperature of at least 20° C. or less, such as less than 10° C., or less than about −60° C. The material properties can be measured using procedures outlined in ASTM standard D4092. It has been found that utilizing materials that have the material properties described herein are able to effectively support and dampen the vibrations imparted on the microphone assembly, such that resonant frequencies were found to be below a 100 Hz, such as less than 80 Hz, or less than 40 Hz. In one example, the material includes butyl rubber.
As shown in
As illustrated in
In some embodiments, the protrusions 308 are positioned and spaced apart in an opposing relationship, such as the first protrusion 308a is positioned opposite the third protrusion 308c, and the second protrusion 308b is positioned opposite to the fourth protrusion 308d. As illustrated in
Each of the first mounting arm 420a, the second mounting arm 420b, and the third mounting arm 420c are coupled to a capsule mount 410 on a distal end opposite the first clamping structure 422a, the second clamping structure 422b, and the third clamping structure 422c, such as at first distal end 424a, second distal end 424b, and third distal end 424c, respectively. Each of the first mounting arm 420a, the second mounting arm 420b, and the third mounting arm 420c include an arm axis, e.g., first arm axis 426a, second arm axis 426b, and third arm axis 426c, that are coplanar and at an angle from each other, e.g., first angle 428a, second angle 428b, and third angle 428c, about a center axis 414. The first angle 428a, the second angle 428b, and the third angle 428c may be equal to each other, unequal to each other, or a combination of both, such that the sum of the first angle 428a, the second angle 428b, and the third angle 428c equals to 360°. For example, the first angle 428a and the third angle 428c may be equal to 110° and the second angle 428b may be equal to 140°. Alternatively, the first angle 428a, the second angle 428b, and the third angle 428c may all be equal to 120°. The first angle 428a, the second angle 428b, and the third angle 428c should be chosen to minimize rotation (e.g., pitch, yaw and roll) of the capsule mount 410 during operation of the microphone assembly 100.
In some embodiments, as shown in
Each of the first mounting arm 460a and the second mounting arm 460b are coupled to a capsule mount 410 on a distal end opposite the first clamping structure 462a and the second clamping structure 462b, e.g., at first distal end 464a and second distal end 464b. Each of the first mounting arm 460a and the second mounting arm 460b include an arm axis, e.g., first arm axis 466a and the second arm axis 466b, that are coplanar and at an angle from each other, e.g., first angle 468a and the second angle 468b, about a center axis 414. The first angle 468a and the second angle 468b may be equal to each other or unequal to each other, such that the sum of the first angle 468a and the second angle 468b equals to 360°. For example, the first angle 468a and the second angle 468b may be equal to 180° such that the first arm axis 466a and the second arm axis 466b are coaxially aligned.
In some embodiments, as shown in
The present disclosure provides a microphone capsule suspension assembly for a capsule in a condenser microphone that allows for improved dampening of unwanted vibrations, reducing noise in the produced acoustic signal of the microphone. The suspension includes a pair of mounting arms made of a material with a hardness that allows for effective damping while also preventing rotation of the capsule during use. The suspension includes a plurality of clamping mounts that serve as the only connection to the microphone housing, effectively isolating the capsule from all other components of the microphone. Isolating the capsule in this manner prevents undamped mechanical vibration from interfering with the capsule and reduces noise.
When introducing elements of the present disclosure or exemplary aspects or embodiment(s) thereof, the articles “a,” “an,” “the” and “said” are intended to mean that there are one or more of the elements.
The terms “comprising,” “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
The term “coupled” is used herein to refer to the direct or indirect coupling between two objects. For example, if object A physically touches object B and object B touches object C, the objects A and C may still be considered coupled to one another—even if objects A and C do not directly physically touch each other. For instance, a fist object may be coupled to a second object even though the first object is never directly in physical contact with the second object.
