1. Field of Invention
The present invention relates generally to stringed musical instruments. Specifically, the present invention relates to providing a transducer saddle system for a stringed instrument.
2. Background of Invention and Related Art
Acoustic stringed instruments typically comprise a hollow body portion coupled to a neck portion extending longitudinally from a side wall of the hollow body portion. Steel, nylon, or other materials are used to make strings that are stretched from the distal end of the neck portion to a point on the top surface of the body portion. At each end, the strings rest on raised bars made of a hard material such as hard plastic or ivory. In guitars, this raised bar is typically called a nut at the neck, and a saddle at the bridge. Each string on a stringed instrument, such as a guitar, is set to a fixed length and tension, the length being fixed between the nut and the bridge. The bridge is a device on the top surface of the body that receives the string and maintains the tension of the string. The bridge further interfaces the strings with body and transfers string vibrations to the guitar top, maintains proper height clearance of strings over the fretted neck, establishes scale length of vibrating string.
Acoustic stringed instruments can be amplified in several ways. A microphone may be placed in front of a sound hole formed on the top surface of the instrument. When plucked, the string vibrates in virtually all axes of direction in the plane perpendicular to the direction of the string. These vibrations are transmitted to the body via the bridge, resonate within the hollow body, and are emitted via the sound hole. The problem with using microphones is that the microphone picks up not only the sound of the vibrating string, but every other sound caused by playing the instrument such as string noise, bumps and taps, as well as ambient noise from other instruments etc. The microphone can further cause feedback by picking up noise from the instruments' vibrating top, which is further amplified by the surrounding speakers/amplifiers.
Also a microphone has a very limited volume range and is ineffective when competing with other amplified instruments.
Another technique involves the use of guitar pickups, in the form of electromagnetic coils, or and piezo-electric transducers. Typically, mechanically coupled acoustic guitar pickup designs employ various types of compressively sensitive transducer materials which are sandwiched between the guitar saddle and the surface of the instrument's bridge or bridge plate. Compressively mounted transducers beneath the saddle tend to have a characteristic pinched and compressed quality of sound. This approach yields little directional biasing or selectivity in the vibratory information that is picked up and amplified. Consequently on an acoustic instrument much micro-phonic noise is collected and amplified along with the desired “musical information”. Micro-phonic noise occurs when a pickup systems axis of sensitivity is mechanically coupled to the instruments resonant top. This coupling sensitizes the entire resonant surface of the instrument through the transducer system, causing every bump or knock on the instrument to be amplified. Micro-phonic sensitivity also increases feedback sensitivity because certain resonant frequency sensitivities in the instrument top become magnified, causing an uncontrollable feedback loop when the amplified signal excites the instruments top and strings through sympathetic resonances. Micro-phonic sensitivity also tends to yield an amplified sound which is “unfocused and boomy,” this occurs when sensitive resonant frequencies in an instrument overpower the rest of the spectrum.
What is needed is an amplification apparatus for a multi-stringed musical instrument that provides uni-directional sensitivity to vertical string vibrations. Additionally, what is needed is a pickup apparatus for a multi-stringed musical instrument which does not microphonocally sensitize the instruments resonant top so as to eliminate micro-phonic noise from the body of the instrument while remaining mechanically responsive to vertical string motion. Also, what is needed is a pickup apparatus for a multi-stringed musical instrument that senses each strings vibrational outputs individually with a high degree of isolation from adjacent strings. This to enable the balancing of the individual strings outputs relative to each other, and to perform this passively through the electro-mechanical calibration of the pickup structure, without relying on a multi channel, active circuit to balance the string output signals.
The purpose of this invention is to provide a highly efficient means of coupling to sensors, vibrations from plucked musical instruments strings. The present invention mechanically conveys vertical aspects of string vibrations to transducers by way of cavities within a saddle body beneath a string saddle crown that establish vertically compliant areas within the saddle. The vertically compliant areas beneath each string are mechanically responsive to vertical string motion. These areas couple the strings to transducers mounted within said cavities, and are selectively sensitive only to vertical string vibrations from the top of the saddle, beneath the string. The uni-directional sensitivity does not respond to vibratory information from beneath the saddle and is only sensitive from its top or positive Z axis direction. This eliminates the introduction of micro-phonic noise from the body of the instrument in the amplified signal. Isolating the vertical component of the string vibration further maximizes fidelity, clarity of sound and responsiveness. The cavities housing the transducers are arranged in alternating phase circuit relationships to avoid phase cancellation effects between the adjacent transducers.
In one embodiment, the present invention is a string saddle system for a multi-stringed instrument, comprising a top saddle crown portion spanning all tensioned strings of said multi-stringed instrument to support the tensioned strings and to receive vibratory energy there from, a body portion beneath said top saddle crown portion having opposing surfaces, said body portion having a plurality of integral cavities, each integral cavity formed in correspondence with a respective string to define a plurality of vertically compliant areas of sensitivity, each vertically compliant area of sensitivity extending vertically from said top portion to said cavity structure and extending horizontally as defined by a length of said integral cavity, each integral cavity including a flexurally responsive transducer element mounted therein for converting vibratory energy from said respective string to an electric signal, said vertically compliant area conveying a vertical component of said vibratory energy to said transducer element via a flexible coupling device.
The system further comprises a first conductor formed on said top surface and each opposing surface of said body, said first conductor having portions connecting a bottom surface location of said transducer device inside of first alternate integral cavity structures, and having portions extending from said top surface for connecting a top surface location of said transducer device inside of second alternate integral cavity structures to form a first conducting path, a second conductor embedded within said body portion having portion for connecting a first [top] surface location of said transducer device inside of said first alternate integral cavity structures, and portion for connecting a second [bottom] surface location of said transducer device inside of said second alternate integral cavity structures to form a second conducting path, wherein said first conducting path and second conducting path conduct electric signals from said transducer devices such that said transducer devices of adjacent integral cavities couple electrical signals of alternating phase relationships to thereby avoid phase cancellation effects between adjacent transducer devices via said first and second conductive paths. The first conductor formed on said top surface and each opposing surface of said body forms a ground plane, the formed ground plane shielding the embedded second conductor.
In another embodiment, the present invention is a string saddle kit for a multi-stringed instrument, comprising a plurality of individual string saddles, each saddle in correspondence with a respective string of said multi-stringed instrument to receive vibratory energy there from, each individual string saddle having a saddle top portion and a saddle body portion beneath said saddle top portion, each saddle body portion of an individual string saddle having opposing surfaces and a top surface, and having an integral internal cavity to define a vertically compliant area of sensitivity for receiving said vibratory energy, each integral cavity including a transducer mounted therein for converting vibratory energy from a respective string to an electric signal, said vertically compliant area of sensitivity providing a sensitized area beneath the string for collection and conveyance of vertical string vibratory energy to said transducer element.
Each saddle body portion of first alternate arranged individual string saddles of said plurality has a first conductor formed on said top surface and each opposing surface of said body, said first conductor having portions connecting a bottom surface location of said transducer inside of a corresponding integral cavity structure, and, a second conductor embedded within said saddle body portion having portion for connecting a first top surface location of said transducer element inside of a corresponding integral cavity structure, and wherein each saddle body portion of second alternate arranged individual string saddles of said plurality having portions of said first conductor extending from said top surface for connecting a top surface location of said transducer element inside of said corresponding integral cavity structure, and portions of said second conductor embedded within said body portion having for connecting a bottom surface location of said transducer element inside of said corresponding integral cavity structure.
Each saddle body portion further has a means interconnecting said first conductive portions of each said individual string saddle of said kit to form a first conducting path, and a means interconnecting said second conductive portions of each said individual string saddle of said kit to form a second conducting path, wherein said first conducting path and second conducting path conduct electric signals from said transducer structures such that said transducer structures of adjacent individual string saddles couple electrical signals of alternating phase relationships to thereby avoid phase cancellation effects between adjacently disposed transducer elements.
Further features, aspects and advantages of the apparatus and methods of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:
The present invention provides a stringed musical instrument pickup comprising a plurality of electromechanical structures that are integrated with a saddle or saddle segments. The saddle or saddle segments comprise articulated cavities beneath each individual string. A top saddle strip supports tensioned strings over a vertically compliant area of the cavity. The articulated cavities are part of a body portion beneath top saddle portion. The body portion has opposing surfaces. Each cavity includes a flexurally responsive transducer element suspended between two mounting points, or suspended at one end from one mounting point. Each transducer element is mechanically and electrically coupled at coupling points via conductive elastomer pads or using a conductive mounting agent such as a conductive epoxy. In alternate embodiments, the transducer element is mechanically coupled at separate mechanical coupling points with electric coupling provided at separate electrical coupling points. The vertically compliant area of the cavity provides a vertically biased area of sensitivity within the saddle/saddle segment corresponding to each string. Vertical displacement of this area of sensitivity below the saddle is transmitted to the horizontally suspended transducer via the pad. The transducer converts this displacement from vibratory energy to an electric signal for each respective string, and is driven by the relative differential in mechanical input between the coupling to the area of sensitivity via the elastomer pad, and the rigid mounting ledges. In one embodiment, the saddle is of a laminated construction and contains four layers of circuit paths. Positive (embedded layer) circuit paths and negative (outside surface layer) circuit paths index to precise points in the body structures corresponding to the mounting and conducting points, and determining the phasing arrangement of the transducers.
The sensitivity of the vertically compliant roof area of the cavity can be increased or attenuated via the thickness of the roof section of each cavity. In addition, sensitivity is adjusted by the thickness (rigidity) of the top saddle strip. Moreover, as shown in
Each cavity structure 120 further includes a flexurally responsive transducer element 124, which is suspended in a beamlike fashion between mounting points 126 formed within a lower surface of each cavity. In example embodiments, the flexural transducers include bender, or bimorph type transducer elements which are a laminate of two piezo ceramic plates with a metal center vane sandwiched between them. Bender or bimorph type transducers are designed to be excited flexurally as opposed to by compression (which is what is typically used for plucked stringed instrument pickups). A unimorph type transducer could also be employed, which is one piezo plate laminated onto one side of a piece of brass. Basically any type of rigid, flexurally responsive transducer element which can be mounted in a beam or cantilever fashion, with exposed, polarized conductive electrodes on its opposing surfaces, could be employed in this structure.
As shown in
The top saddle strip 101 is the load bearing part of the structure that supports a tensioned string of an instrument. The saddle 101 thus transmits vibrations induced in the string of the instrument to the respective vertically compliant area 122 of the saddle body portion immediately below. The vibrations may be induced by plucking the string, bowing, or any other means. The cavity 120 in the body portion 110 is in essence an elongated slot. The physical dimensions of this slot 120 are dictated by the size of the saddle, depending upon the type of stringed instrument in which it is installed. Generally, the more elongated the cavity 120, the more sensitized the vertically compliant area 122. In other words, string to string output balances may be calibrated mechanically by elongating the individual articulated cavities 120 horizontally. This increases the degree of vibratory compliance of the individual vertically compliant area and thus increases the amount of vibratory energy conveyed to the associated transducer 124. The result is louder output for that particular string. The optimal size is a balance between sensitivity and structural integrity (to protect the delicate transducer element within) and will be evident to one skilled in the art, depending on the appropriate application.
The upper pad 128 of the two small, conductive elastomer pads mechanically couples a point on the underside of the vertically compliant area 122, to a point on the suspended transducer 124 below. In one embodiment, the pad 128 is nested and compressed into the vertically compliant area of the saddle. In another embodiment, the pad 128 is compressed between a ramped roof area on the underside of the vertically compliant area of the saddle. The upper pad thus mechanically couples the vertical area of sensitivity 122 to the horizontally suspended, flexurally responsive transducer element 124. The upper pad additionally provides electric coupling of the top surface of the transducer element to a positive (or negative circuit path depending on the phasing of the adjacent transducers), as shown in
The lower of conductive elastomer pad 129 also makes an electrical connection between the bottom face of the transducer and the ground/negative plane or to the positive circuit path depending on the phasing of the transducer 124. The lower pad is only an electrical coupling in the optimal embodiment. The lower pad does not have to mechanically couple the transducer to any vibratory input. In an alternate embodiment, as shown in
The transducer elements 124 receive vibratory energy from the vertically compliant area of sensitivity via the mechanical coupling provided by the upper elastomer pad 128, and convert the vibratory energy to electrical energy. The transducer is driven by vibrations from the vertically compliant area via the coupling pads. The transducer is essentially responding to the relative differential in mechanical input between the coupling to the area of sensitivity via the elastomer pad, and the rigid mounting ledges in one embodiment. In one embodiment, shown in
In
In
The saddle system, by way of its internal cavity structures is directionally sensitive to vertical string vibrations conveyed along a single axis, e.g., on its positive Z axis. It is highly desensitized to vibrations from below, or negative Z axis direction. There is also very little sensitivity on the X and Y axis because the rebated areas in the saddle, on both sides of each vertically compliant area isolate the sensitized vertically compliant areas from the walls of the saddle slot, and the sensitized, receptive area of the suspended transducer is coupled only to the isolated vertical compliant area. So only vertical vibrations are sensed. This directional sensitivity decouples the pickup system from the top surface of the body of the instrument, thus providing a non micro-phonic relationship to the resonant instrument top. The lack of micro-phonic sensitivity reduces feedback and eliminates the amplification of spurious body noise from handling of the instrument. This yields a very clear, and focused sounding audio signal from each string.
In addition, the front and back face of each vertically compliant area are free to vibrate by way of clearance pockets on the front and back face of the saddle corresponding to the areas of sensitivity. These rebated areas prevent the sensitized areas of the structure of the cavity from contacting the sides of the slot in the saddle plate in which the saddle is mounted, as shown in
Body portions 210a,b further comprise a plurality of cavities, two of which are represented by 220. The cavities, by way of their structure, define and form a vertically compliant area of sensitivity 222 for each respective string. Transducer elements 224 are mounted within the cavities, held in place by mounting points in a beamlike fashion, and are electrically and mechanically coupled to the top and bottom surfaces of the cavity. Additionally the transducers may be glued or epoxied in place at one or both ends to the mounting points, i.e., cavity bottom inner surface ledges. In one embodiment, the mounting points are located at ledge portions formed along the horizontally elongated cavity. The top surface of a transducer element 224 is mechanically coupled to the bottom surface of the vertically compliant area 222 of the cavity housing the transducer element via conductive elastomer pads including bottom pad 228 and top pad 229. In one embodiment, the pads are fitted into respective bisected holes or mounts 239 and/or arch shaped (e.g., concave) nest 238, located and formed as part of the lower bottom inner cavity surface (pad 239) and upper inner cavity surface (pad 238). However, as described in greater detail herein with respect to
That is, in each of the embodiments described in connection with
Preferably, each top ramped roof portion is coated with a conductive paint to increase the conductive surface area between the embedded circuit (at the electrical contact point) and the conductive pad.
As shown in
More particularly, in accordance with the present invention, as shown in the exploded view of
The positive and negative circuit paths index to precise electrical coupling points in each cavity structure which correspond to the locations of the coupling pads for electrically coupling (and/or mounting) the transducer element in the cavities and determine the phasing arrangement of the transducers. Referring to a first cavity 221, as shown in
Conversely, it will be observed that the immediately adjacent (neighboring) cavity 220 has a negative circuit path contact 234′ in contact with the bisected hole (conductive pad nest structure) for an upper conductive pad coupled to the respective transducer element at a first (top) transducer location. Negative circuit contact 234′ is in contact with ground plane 231 (and outside surface ground plane 230, since all ground planes are at the same potential). Further, it will also be noticed that embedded positive circuit path 232 includes positive circuit connection 233″ that is in contact with the bisected hole (conductive pad nest structure) corresponding to the lower conductive pad 229 coupled to the respective transducer element at a second (bottom) transducer location. In other words, transducer element 224 in cavity 220 has its top surface grounded and its bottom surface coupled to the positive circuit path. Note that at this cavity, the outer ground plane 230 includes a rebated pocket 249 to prevent the lower conductive pad 229 from shorting the outside conductor (e.g., negative ground plane). This configuration is similar for alternative cavities 220 shown in
With respect to the rebated pocket, in order to prevent a short circuit, the bottom conductive pads electrically coupling the transducer to the positive (embedded) circuit path (e.g., pad 229a shown in
In general, referring back to
Moreover, as transducer and other pickups are generally sensitive to magnetic fields generated by transformers, fluorescent lamps, and other sources of interference, pickup hum and noise generated from these sources are eliminated. That is, according to the invention, the transducers in the present embodiment are electrically shielded (such as by a Faraday shield formed by the ground conductors on outer body portion surfaces and on surface top), signals (i.e. signals such as hum) are eliminated. Furthermore, since only vertical components of string vibrations are detected along the Z-axis by the vertically compliant areas, other vibrations from the body of the instrument or string noise are not picked up.
In one embodiment, the body portions 210a,b can be constructed from a lamination of copper clad printed circuit board (PCB) material or any other suitable substrate material upon which a conductive layer or skin is attached to the surfaces. The ground/negatively coupled layer is clad on both outside surfaces with copper or an equivalent conductive layer, and the positively coupled lamination layer is clad the inside surfaces of body portions 210. The body portions are then laminated together with an adhesive, with the positive circuit paths sandwiched inside, while the ground planes on the top, outer sides and (optionally) bottom surfaces provide Electromagnetic Interference (EMI) shielding of the embedded positive circuitry. The laminated body portions may be indexed together with pins. Particularly, as shown in
In one exemplary embodiment, as further shown in
The top saddle strip 201 is adhered onto the body structure with glue, i.e., a conductive epoxy. The electric connection between the conductive epoxy ground plane and the side ground planes on the main body occurs at the non rebated areas where the side ground planes on the main body meet the underside of the top saddle strip that has the conductive epoxy adhesive layer. The conductive adhesive ground plane layer under the saddle strip also connects the side ground planes on the body structure to embedded negative contact points 234, 234′ for the conductive elastomer pads beneath the saddle strip.
In one embodiment, as described, bisected holes in the transducer support ledges clasp conductive elastomer pads. Conductive paint is applied to the insides of the holes to increase the conductive surface contact area. In the case of the bottom negative connections the conductive paint extends the negative outside ground planes circuit path into the inner surface of the bottom negative containment structures. In the case of said second electrical coupling points inside of said second alternate integral cavity structures, the conductive paint extends within the electrically indexed containment structure to contact the first conductor on opposing body surfaces.
The conductive elastomer pad, contacting a conductive surface coating, is clasped in the holes within each cavity and makes electrical contact with the internal (positive) and external (negative) circuit paths. The conductive pads are situated transverse with respect to the length of the body portion, and extend slightly out of the top of the supporting structure (nest or ledge) and beyond the surface of the ledge. The transducer rests upon the ledge where the clasped elastomer pads are exposed, thereby making the appropriately phased electrical contacts to the electrode surfaces of the transducer. In the embodiments depicted in
As further shown in
For the above-described embodiments, the top of the saddle may be shaped as desired to accommodate the strings. For instance, classical guitars do not have a radius in the saddle, and the saddle is flat with no arc. The figures show a top saddle strip that is horizontally aligned along an axis, with the integrated cavities being in corresponding horizontal alignment. However, the top saddle structure may be arcuate shaped, to correspond to the radius of the fretboard of the stringed instrument with the integrated cavities being aligned according to said arcuate shape. Further, the height of the entire structure of the multi transducer saddle may be shimmed from beneath to adjust the overall height. Alternatively, a height-adjusting means may be provided in the form of adjustment screws, or equivalent. This adjustment means may be incorporated into a saddle plate for holding the saddle, the saddle plate being represented in
As a further modification to the embodiment of
In a further alternative embodiment, the entire string saddle and body is divided into mechanically and electrically discrete individual saddle body segments, a separate and discrete segment supporting each string. Each discrete saddle/body segment containing all the described elements for transducer mounting, circuitry and electrical and mechanical coupling of a suspended transducer and supporting an individual tensioned string over each separate corresponding top and body portion segment. This embodiment, referred to as a string saddle “kit”, comprises a plurality of individual string saddle segments, each saddle segment in correspondence with a respective string of an instrument to receive vibratory energy there from. The benefits of such an arrangement are many, including the ability to individually alter the total length of each string (also known as intonation), individual string height adjustment, as well as the flexibility to install multiple string saddles and wire them individually to an output or processor for flexible signal processing. Moreover, this second embodiment allows for additional flexibility as the discrete individual saddle body segments of the kit are replaceable, and the individual saddle segments could be customized by a luthier for different intonation setups as needed.
Similarly, saddle system 400B comprises body portions 410B that have their outer surfaces laminated with ground plane 430B. Unlike saddle system 400A, however, one or both body portions 410B have an inside surface portion provided (e.g., laminated) with a top conductive portion that connects with negative circuit path 434 via a top ground plane. Further, the inside surface of at least one body portion is laminated with positive circuit path 432 that is situated for contacting a bottom surface of transducer element within the cavity in a manner as described with respect to cavity 220 of
Referring still to
A plurality of individual saddle systems 400A and 400B may be arranged on a stringed instrument in an alternating manner. The individual transducer signal paths would thus couple electrical signals of alternating phase relationships to avoid phase cancellation effects between the adjacently disposed transducer elements as in the unitary saddle design.
The individual, single cavity saddle systems each have their own cable with a positive and negative lead. For example, for each individual saddle segment, a single shielded connector cable may provide isolated signal output from each respective string saddle segment. The shielded connector cable including a positive polarity output cable connection for soldered connection to the embedded second conductor at an internal connecting point, and, a ground output cable connection for soldered connection to an external circuit soldering point on the external ground plane of an outside body surface of the saddle segment. The solder attach positions are at the bottom of the back face of each saddle. The individual saddle cables can all be either wired together externally or each saddle output can be run individually to a separate channel in a multi channel pre amp, wherein a separate preamplifier enables individual processing of a respective string's discrete output. This would provide additional flexibility in adjusting individual volumes for each string as well as polyphonic output for applications such as MIDI interface to a polyphonic synthesizer module. The individual cables' respective contact points may be incorporated into the body portion of the musical instrument, in the form of a notched slot or like recess for receiving a plurality of dual-polarity output connector to transmit the signal via an instrument cable adapted to receive signals from the plurality of saddle systems.
Saddle Plate
While the invention has been particularly shown and described with respect to illustrative and preformed embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention which should be limited only by the scope of the appended claims.
Number | Name | Date | Kind |
---|---|---|---|
4860625 | Mathews | Aug 1989 | A |
4867027 | Barbera | Sep 1989 | A |
5078041 | Schmued | Jan 1992 | A |
5218159 | McClish | Jun 1993 | A |
5410101 | Sakurai | Apr 1995 | A |
5817966 | Fishman | Oct 1998 | A |
6255568 | Dunwoodie | Jul 2001 | B1 |
6822156 | Lazarus et al. | Nov 2004 | B1 |
7230174 | Wilson | Jun 2007 | B1 |
7394015 | Takabayashi | Jul 2008 | B2 |
20020157523 | Takabayashi | Oct 2002 | A1 |
20040105560 | Naniki | Jun 2004 | A1 |
20040134330 | Braun et al. | Jul 2004 | A1 |
20060219093 | Urbanski | Oct 2006 | A1 |
20070131082 | Feiten et al. | Jun 2007 | A1 |
20080011146 | Dunwoodie | Jan 2008 | A1 |
20090038461 | Dunwoodie | Feb 2009 | A1 |
20100116123 | Barbera | May 2010 | A1 |
Number | Date | Country |
---|---|---|
1 717 795 | Nov 2006 | EP |
10-0578076 | May 2006 | KR |
Number | Date | Country | |
---|---|---|---|
20100116123 A1 | May 2010 | US |