The present invention relates to the field of microphone mounts, and more particularly to a microphone isolation mount for reducing and/or preventing the detection of vibrations.
Because sound is transmitted as a series of pressure waves through air, a common form of microphones used across multiple industries and technologies includes a diaphragm to detect these pressure waves. The changes in pressure cause the diaphragm to flex, and this flexion is converted into a signal by the microphone. This signal may then be transmitted to a speaker, for example, whereupon it can be converted back into sound.
However, a number of external sources, other than sound, may induce movement or flexion within the microphone diaphragm. As the microphone cannot differentiate between the sources of diaphragm flexion, all flexion of the diaphragm is captured as a signal representative of sound, even flexion caused by the external sources other than sound.
Further, other external sources that may induce movement within the microphone diaphragm may be caused by the microphone being bumped, nudged, impacted or otherwise knocked and where shock force is applied to the object supporting the microphone. Importantly, low level vibrations can also result in flexion of the microphone diaphragm. These and other external sources are broadly referred to herein as “non-sonic vibrations”.
All of these non-sonic vibrations recorded by the diaphragm and misidentified as sound are typically transmitted into the microphone body from the object to which the microphone is mounted. These objects may include microphone stands, microphone booms, or a ceiling mount, as typically employed in some recording studios.
One conventional way of preventing a microphone from misidentifying these non-sonic vibrations as sound is to mount the microphone to an isolation mount, which may comprise a mounting bracket suspended on one or more suspension spring elements, together with a method (integral or otherwise) of damping the displacement of the spring elements.
This is mechanically described as a mass-spring-damper system, wherein the microphone and/or the object to which the microphone is mounted functions as the mass, the suspension element functions as the spring to absorb non-sonic vibrations, and there are one or more damping elements that release, or dissipate, the absorbed kinetic energy of said non-sonic vibrations (typically as heat). Some isolation mounts are designed such that their suspension elements have inherent or integral damping due to the physical properties of the material and/or its shape, while others use a separate damping element in mechanical communication with the suspension element.
In designing a microphone isolation mount, it is desirable to design a mount with a low resonant frequency. The resonant frequency of the suspension element of the isolation mount may be indicative of the lower frequency bound of vibrations that the suspension element may successfully absorb. As such, one generally wants to design an isolation mount to have a resonant frequency that is as low as possible.
One example of a conventional isolation mount is illustrated in
Such prior art systems, however, often suffer from some drawbacks. As the skilled person will appreciate, the suspension elements must provide both structural support for the mounted microphone, and must also function as a mass-spring-damper system in order to enable isolation. In providing ‘omnidirectional’ isolation, the cords must provide both flexion and support for the microphone equally in all direction. As such, it is impossible to prevent displacing forces being translated across axes, thus causing the microphone to wobble. In other words, the isolation mount of
Another example of a conventional isolation mount is disclosed in United States patent publication no. US 2009/0016558 and illustrated in
Yet another example of a conventional isolation mount is shown in
The prior art isolation mounts depicted in both
This form of isolation mount, sold under the trade name of “Lyre” mount, suffers from the difficulty in ensuring that displacement is evenly distributed across the recurved arm length. Further, as a result of the ‘rocking’ motion, longitudinal movement of the isolation mount relative to the microphone may also translate in a lateral or vertical movement. This may reduce the effectiveness of such isolation mounts by permitting some undesired translation of forces across axes, to the detriment of stability. Furthermore, the large size and profile of the recurved arm of conventional mounts may not be desirable.
Accordingly, there is a need for an isolation mount that overcomes one or more of the disadvantages of the prior art. In particular, there is a need for an isolation mount that is configured to have a lowered resonant frequency, that is configured to provide a high level of compliance (and therefore isolation) in at least one direction without sacrificing the ability of the mount to support the microphone, and that is configured to provide a greater degree of energy absorption than conventional directional isolation mounts.
In one aspect, an isolation mount for a microphone having an address axis may include a base configured to attach to an object, a mounting assembly adapted to securely receive the microphone therein, and a suspension element extending between the base and the mounting assembly, the suspension element comprising a first end affixed to the base, a second end affixed to the mounting assembly and a rolling spring extending therebetween, wherein the rolling spring is arranged to form an arc having an opening substantially aligned to the address axis of the microphone.
The suspension element may further include a first and second rolling spring and the rolling spring bodies are arranged such that their respective arc openings are substantially aligned to the address axis of the microphone in opposing directions. The first rolling spring may be positioned substantially above the second rolling spring. Alternatively, the first rolling spring may be substantially coplanar with the second rolling spring.
Further, the rolling spring may be configured such that the formed arc is substantially coplanar with the address axis.
Moreover, the first and second rolling spring bodies may be configured such that their respective formed arcs are individually coplanar with the address axis. Alternatively, the first and second rolling spring bodies may be configured such that a first moment induced within the first rolling spring may be substantially cancelled by a second opposing moment induced within the second rolling spring.
In another aspect, a first and second isolation mount may be arranged to attach to and support a microphone at multiple points along the address axis. The first and second isolation mounts may share a common base. Further, the first and second isolation mounts may share a common mounting assembly.
In yet another, the microphone has two perpendicular address axes forming an address plane, the suspension element may be a plurality of suspension elements each extending between the base and the mounting assembly, arranged such that the arc openings of their respective rolling spring bodies may be aligned with the address plane in an array of directions. The plurality of suspension elements may be radially arranged about the mounting assembly. Alternatively, the plurality of suspension elements may be arranged in a nested configuration, whereby a sequential chain is formed by the plurality of suspension elements between the base and the mounting assembly.
It is further contemplated that the suspension element may be a ribbon having a width oriented substantially perpendicular to the address axis.
Embodiments are illustrated by way of example and not limitation in the figures in the accompanying drawings, in which like references indicate similar elements and in which:
FIG. TOA illustrates an exemplary isolation mount including a plurality of suspension elements arranged radially around a mounting assembly;
For purposes of this application, the term “kinetic energy” refers to energy from any source of vibration or movement (other than air-borne sound) that can be transmitted to create movement of the diaphragm of a microphone, relative to its backplate or structure, and mistakenly recorded or identified as sound.
For purposes of this application, the term ‘non-sonic vibration’ refers to external forces, other than sound, that may induce vibration, shifting or other forms of movement in a microphone diaphragm and will be incorrectly detected as sound due to movement of the microphone diaphragm. For instance, non-sonic vibrations may include shock forces such as a microphone or the microphone base being bumped, knocked or otherwise receiving an impact, or other vibration sources such as machinery, footsteps, or similar. Furthermore, as used herein the term should be understood to not only apply to non-sonic vibrations that are directly applied to the microphone, microphone mount or an object that the microphone is mounted to, but also to non-sonic vibrations that may be transmitted to one of the above.
For purposes of this application, the terms “address axis” and “address plane” refer to the directions for which a microphone may be designed to pick up sound. A microphone having an address axis is typically configured to be directional, and to preferentially detect sounds only from a particular direction that substantially extends along the address axis, or otherwise at an acute angle to the address axis (less than 45°). On the other hand, a microphone having an address plane may be configured, or may be mounted, to detect sounds from directions within any angle on the address plane. This may be through the use of multiple diaphragms, through the microphone being able to rotate, or through any other means known in the art that enables a microphone to be able to be addressed from multiple directions.
For purposes of this application, the term “vector component” refers to a portion of a vector that extends along an axis. By way of non-limiting example and with specific reference to
Turning now to the drawings wherein like numerals represent like components,
As shown, base assembly 102 may be U-shaped. Other shapes of base assembly 102 are contemplated including, for example, circular shaped, rectangular shaped, and the like. Moreover, base assembly 102 may include a lower section 108 and an upper section 110. As shown, lower section 108 may be configured to removably attach to an object via fastener 109. For instance, lower section 108 may be removably attached to a camera via a fastener, such as screws, nuts and bolts. Other way of attaching base assembly 102 to an object are contemplated, such as through use of clips and/or magnets.
Mounting assembly 104 may define an opening 105 configured to securely receive a microphone. More specifically, mounting assembly 104 may include C-clips or clamp elements 112 configured to encompass and/or grip a portion of a microphone. More specifically, as shown, a microphone, positioned according to address axis 114, may be mounted to isolation mount 100 via clamp elements 112 of mounting assembly 104.
Furthermore, clamp elements 112 may be adjustable to a number of variable positions to, for example, facilitate receiving microphones of various diameters. As a result, isolation mount 100 of
As further shown in
The width of suspension elements 106 may range between about ten millimeters to about twenty millimeters, and preferably between about twelve millimeters and about seventeen millimeters. In one embodiment, suspension elements 106 may have an approximate width of about fifteen millimeters.
The depth of suspension elements 106 may range between about five millimeters to about fifteen millimeters, and preferably between about eight millimeters and about twelve millimeters. In one embodiment, suspension elements 106 may have an approximate depth of about ten millimeters. The thickness of suspension elements 106 may range between about half of a millimeter to about one millimeter. In one embodiment, suspension elements 16 may have an approximate thickness of about eight tenths of a millimeter.
Suspension elements 108 may be configured to extend between upper section 110 of base assembly 102 and clamp elements 112 of mounting assembly 104. More specifically, as shown, suspension elements 106 may include a first end 115 and a second end 116. First end 115 may be affixed to upper section 110 of the base 102. Second end 116 may be affixed to clamp element 112 of mounting assembly.
Suspension elements 106 may further include a rolling spring 118 between first end 115 and second end 116. Rolling spring 118 may be shaped to form an arc having an opening substantially aligned to address axis 114 of the microphone, as depicted by arrow 120. More specifically, the arc formed by rolling spring 118 may range between about 40 degrees and about 70 degrees, and preferably be about 60 degrees. While it is not necessary for first end 115 and second end 116 to be arranged perpendicular to the address axis 114, such a configuration is contemplated.
The structure of isolation mount 100 may be configured to mechanically function as a mass-spring-damper system. For instance, the mass may be the mounted microphone and rolling spring 118 of suspension element 106 may act as the spring. It is contemplated that the material and structure of suspension element 106 may facilitate inherently damping (also known as integral damping) of non-sonic vibrations. Alternatively or in addition, isolation mount 100 may further include a separate damping element (not shown) in mechanical communication with suspension element 106.
As shown in
For instance,
Additional details regarding suspension elements and rolling spring are provided below. Although reference will be made to suspension elements 106 and rolling spring 118 of
Exemplary Function of Suspension Elements
Exemplary functions of suspension elements 106 may include acting as a spring that undergoes “rolling flexion.” More specifically, as shown in
As shown in
A comparison of
Furthermore, rolling spring 118 may be a type of spring having an inherently low internal tension. As a result of the lowered tension, rolling spring 118 may naturally possess a lowered fundamental oscillation frequency, which means that it may be induced to undergo movement (and thus ‘rolling flexion’) by lower-frequency non-sonic vibrations. In other words, rolling spring 118 may facilitating forming the ‘spring’ of a mass-spring-damper system to, for example, improve isolation of a mounted microphone from low-frequency vibrations.
Vector Components of Vibrations
It is contemplated that, non-sonic vibrations being transmitted through the object into the isolation mount 100 may not always align with address axis 114 of a mounted microphone. Nevertheless, and with reference to
Rolling spring 118 may be configured to absorb the vector component of a non-sonic vibration that is parallel to address axis 114 of a mounted microphone. Furthermore, any remaining vector components of a non-sonic vibration may be essentially perpendicular to address axis 114. As a result, the microphone may not readily detect remaining vector components of a non-sonic vibration.
Multi-Axial Isolation
It is further contemplated that an isolation mount as shown and described herein may facilitate isolating a microphone from non-sonic vibrations in multiple directions, or from multiple vector components of a non-sonic vibration. For example, a side-address microphone, which are typically designed to pick up sounds from a plurality of co-planar directions, may benefit from isolation from non-sonic vibrations. It is noted that a microphone's ability to detect sounds from a number of directions does not affect the spirit and scope of this disclosure.
More specifically, mounting assembly 404 of isolation mount 400 may include an inner section 410 and an outer section 412. As shown, suspension elements 406 may extend radially between outer section 412 and base assembly 402. Each suspension element 406 may include a rolling spring 414, which may be aligned with address plane 408, but opening in different directions. The positioning of suspension element 406 facilitates absorbing non-sonic vibrations along their respective opening directions (represented by array of arrows 416 of
Although not shown, it is contemplated that multi-axial isolation may be provided through a combination of two or more aspects disclosed above. For example, an isolation mount may include a base assembly configured to attach to an object, a mounting assembly, a connector, and two suspension elements. A rolling spring of a first suspension element may form an arc opening in a first direction, while a rolling spring of a second suspension element may form an arc opening in a second, substantially perpendicular direction. Each of the first and second suspension elements may be configured to absorb non-sonic vibrations travelling in either the first or second direction (or along the plane formed by the first and second directions).
Furthermore, a multi-axial isolation mount may include a second connector and a third suspension element between the base assembly and the mounting assembly. The third suspension element may include a rolling spring forming an arc opening in a direction substantially perpendicular to the first and second suspension elements. As a result of the three substantially perpendicularly positioned suspension elements, a multi-axial isolation mount may facilitate three-dimensional isolation of a mounted microphone.
Improved Sensitivity for Low-Amplitude Isolation
More specifically, each suspension element 506, 508 may include a rolling spring 510, 512. As shown, rolling springs 510, 512 may be arranged to form arcs opening in substantially opposing directions as indicated by opposing arrows 514, 516. As illustrated in
With regard to
Further, suspension element 806 may be substantially coplanar with an address axis 814 of a microphone. In other words, the plane of rolling spring 808, depicted by the dashed line 816, may be aligned with the address axis 814. This may be contrasted against isolation mount 200 of
Isolation mount 800 of
Referring back to
It is further contemplated that isolation mounts, such as those described herein, may comprise suspension elements arranged on either side of a microphone. As such, it is not necessary for suspension elements on either side of the microphone to be coplanar with one another. Rather, they may be configured to be coplanar with an address axis of the microphone.
Providing Longitudinal Support
Furthermore,
Ribbon Structure to Improve Compliance
It is further contemplated that isolation mounts, such as those shown and described herein, may include suspension elements that may be formed from a flattened suspension ribbon, wherein the ribbon width may be oriented substantially perpendicular to the address axis. Such isolation mounts may facilitate increasing the compliance of the suspension element in directions parallel to the address axis, which may provide a decrease in the resonant frequency of the suspension element. This may result in an improved isolation of the microphone received by the isolation mount from non-sonic vibrations. It is further contemplated that formation of the suspension element into a ribbon may result in the strength of the suspension element- and ability to support stably a mounted microphone—to be maintained or even improved.
It is further contemplated that a ribbon-type suspension element may be configured to absorb non-sonic vibrations (or a vector component thereof) that are substantially parallel to the address axis through rolling flexion. For instance, a first end and a second end of a suspension element may move in directions parallel to one another, without their perpendicular separation distance appreciably changing. With this rolling motion, the radius of the arc may not appreciably change. Rather, the suspension element may roll as it curls and uncurls in equal proportion due to parallel movement of the first and second ends. As a result, ribbon-type suspension elements, such as those shown in
It is further contemplated that non-sonic vibrations (or a vector component thereof) which are perpendicular to the address axis and normal to a surface of the ribbon are absorbed through contractive/expansive flexion of the suspension element. This may allow for a first end and a second end of the suspension element moving closer together (or further apart) relative to each other, such that the suspension element may be considered to close or open, respectively. As a result, the radius of the formed arc of the rolling spring may change as the suspension element flexes open or closed. Further, the suspension element will be more resilient to such an action, and so the isolation mount will have a lesser degree of freedom of movement in these directions. The suspension element may therefore have a lower compliance in these directions, and so may be less able to isolate the mounted microphone from non-sonic vibrations along this axis. In at least one embodiment, such a configuration is contemplated to provide the high degree of compliance along the address axis—being the most desired axis for high compliance—without sacrificing the structural stability of the isolation mount.
It is further contemplated that non-sonic vibrations (or a vector component thereof) in a direction perpendicular to both directions disclosed above are absorbed through torsion of the suspension element, whereby the suspension element twists along its length. The suspension element may have the highest resilience against movement along this axis and may be configured to strongly resist torsion, and so the isolation mount will have minimal degree of freedom of movement in this direction. As a result, the isolation mount may have minimal, lowered or almost negligible ability to absorb and subsequently dissipate non-sonic vibrations in these directions. In at least one embodiment, such a configuration is contemplated as this particular direction may be aligned with the vertical axis—and therefore, the isolation mount needs a high degree of strength and stiffness to support the weight of the microphone.
Long Ribbon Structure
In addition to the advantages detailed above for ribbon-type suspension elements,
Long ribbon suspension elements may be made from a stiffer injection mold resin (e.g., plastic) to, for example, balance (support and isolate) a wide range of microphones. The stiffness of resin may range. For instance, a flexural modulus may range from about 200 MPa to about 1500 MPa, and preferably about 550 MPa to about 1150 MPa. Although other resin stiffness is contemplated, a long ribbon structure with stiffer resins may eliminate the need to add a damper element. In other words, the resins viscous properties of long ribbon suspension elements may be configured to absorb energy, which may then be converted to heat.
The height of long ribbon suspension elements may range between about thirty millimeters to about sixty millimeters, and preferably between about forty millimeters and about fifty millimeters. In one embodiment, long ribbon suspension elements may have an approximate height of about forty-five millimeters.
The width of long ribbon suspension elements may range between about five millimeters to about twenty millimeters, and preferably between about eight millimeters and about twelve millimeters. In one embodiment, long ribbon suspension elements may have an approximate width of about ten millimeters.
The thickness of long ribbon suspension elements may range between about a quarter of a millimeter to about two millimeters, and preferably between about half of a millimeter and about one and a half millimeters.
The depth of long ribbon suspension elements may range between about five millimeters to about twenty millimeters, and preferably between about ten millimeters and about fifteen millimeters. In one embodiment, long ribbon suspension elements may have an approximate depth of about fourteen millimeters.
Referring now to
Mounting assembly 1604 may be structured to allow a user to access easily buttons on a microphone. In particular, mounting assembly 1604 may include C-clips 1614 to, for example, receive a microphone having a diameter ranging from about fifteen millimeters to about thirty millimeters, and preferably between about twenty-two millimeters to about twenty-three millimeters.
The height of isolation mount 1600 may range between about forty millimeters to about fifty millimeters. In one embodiment, isolation mount 1600 may have an approximate height of about forty-six millimeters. The length of isolation mount 1600 may range between about fifty millimeters to about seventy millimeters. In one embodiment, isolation mount 1600 may have an approximate length of about sixty-eight millimeters.
The width of isolation mount 1600 may range between about forty millimeters to about seventy millimeters, and preferably between about fifty millimeters and about sixty millimeters. In one embodiment, isolation mount 1600 may have an approximate width of about fifty-eight millimeters.
As shown in
In addition, suspension elements 1606, 1608 may have varying stiffness, such as flexible, medium and/or stiff. In one example, front suspension element 1606 may be less stiff as compared to rear suspension elements 1608. If stiffness of front and rear suspension elements 1606, 1608 is matched to a given microphone and its center of gravity/mass, excitation vertically and also to the side, centered around a certain key frequency range, may result in a neutral zone where motion/deflection is reduced. Deflection to the extremities of the microphone may be high but the neutral zone, where the sensitive capsule diaphragm (pick-up) element is located remains fairly stable as mechanical induced noise and/or vibration may be reduced.
The height of isolation mount 1700 may range between about forty millimeters to about fifty millimeters. In one embodiment, isolation mount 1700 may have an approximate height of about forty-six millimeters. The width of isolation mount 1700 may range between about forty millimeters to about seventy millimeters, and preferably between about fifty millimeters and about sixty millimeters. In one embodiment, isolation mount 1700 may have an approximate width of about fifty-eight millimeters.
The length of isolation mount 1700 may be adjustable depending on, for example, where base assemblies 1702, 1704 are coupled to a block 1703. For instance, the length of isolation mount 1700 may range between about fifty millimeters to about seventy millimeters. In one embodiment, isolation mount 1700 may have an approximate length of about sixty-eight millimeters.
As shown in
Suspension elements 1706, 1708 may have varying levels of stiffness, such as flexible, medium and/or stiff. It is further contemplated that each pair of long ribbon suspension elements 1706, 1708 may have the same thickness. Alternatively, long ribbon suspension elements 1706, 1708 may have a different thickness. For instance, front suspension elements 1706 may have a thickness of about one millimeter and rear suspension elements 1708, may have a thickness of about one and four tenths millimeters. Other thicknesses are contemplated.
The height of isolation mount 1800 may range between about fifty millimeters to about sixty millimeters, and preferably between about fifty-two millimeters and about fifty-five millimeters. The width of isolation mount 1800 may range between about forty millimeters to about seventy millimeters, and preferably between about fifty millimeters and about sixty millimeters. In one embodiment, isolation mount 1800 may have an approximate width of about fifty-eight millimeters.
Similar to isolation mount 1700 of
As shown in
Further, front and rear long ribbon suspension elements 1810, 1812 of isolation mount 1800 may be separated for tooling purposes and for allowing a user to visualize graphics and access buttons on the microphone. As shown, each pair of long ribbon suspension elements 1810, 1812 may include two rolling springs 1818, 1820. Rolling springs 1818, 1820 may be angled and/or opposing one another.
Suspension elements 1806, 1808 may have varying levels of stiffness, such as flexible, medium and/or stiff. It is further contemplated that each pair of long ribbon suspension elements 1806, 1808 may have the same thickness. Alternatively, long ribbon suspension elements 1806, 1808 may have a different thickness. For instance, front suspension elements 1806 may have a thickness of about one millimeter and rear suspension elements 1808, may have a thickness of about one and four tenths millimeters. Other thicknesses are contemplated.
The height of isolation mount 1900 may range between about thirty millimeters to about fifty millimeters, and preferably between about forty millimeters and about forty-five millimeters. The length of isolation mount 1900 may range between about thirty millimeters to about sixty millimeters, and preferably between about thirty-five millimeters and about fifty-five millimeters. The width of isolation mount 1900 may range between about forty millimeters to about sixty millimeters, and preferably between about forty-five millimeters and about fifty-five millimeters. In one embodiment, isolation mount 1900 may have an approximate width of about fifty millimeters.
As shown in
When used in the context of ‘substantially parallel’ or ‘substantially perpendicular’, the term substantially should be regarded as permitting an angular deviation from the stated alignment, insofar as the working of the invention is still enabled, without departing from the scope of the invention.
While the invention has been described with reference to preferred embodiments above, it will be appreciated by those skilled in the art that it is not limited to those embodiments, but may be embodied in many other forms, variations and modifications other than those specifically described. The invention includes all such variation and modifications. The invention also includes all of the steps, features, components and/or devices referred to or indicated in the specification, individually or collectively and any and all combinations or any two or more of the steps or features.
In this specification, unless the context clearly indicates otherwise, the word “comprising” is not intended to have the exclusive meaning of the word such as “consisting only of”, but rather has the non-exclusive meaning, in the sense of “including at least”. The same applies, with corresponding grammatical changes, to other forms of the word such as “comprise”, etc.
Other definitions for selected terms used herein may be found within the detailed description of the invention and apply throughout. Unless otherwise defined, all other scientific and technical terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which the invention belongs.
Further modifications and alternative embodiments of various aspects of the invention will be apparent to those skilled in the art in view of this description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the general manner of carrying out the invention. It is to be understood that the forms of the invention shown and described in the application are to be taken as examples of embodiments. Components may be substituted for those illustrated and described in the application, parts and processes may be reversed, and certain features of the invention may be utilized independently, all as would be apparent to one skilled in the art after having the benefit of this description of the invention. Changes may be made in the elements described in the application without departing from the spirit and scope of the invention as described in the following claims.