US 3542936 A
Description (OCR text may contain errors)
Nov. 24, 1970 R. c. BABlcKY 3542,936
VIBRAHARP RESONATORS WITH ELECTRO-MECHANCAL PICKUP MEANS Filed June 1'7, 1968 Mam/470p I 38 4 26' III *x 28 34 38 324030 Raymond C. Babia/cy INVIL'N'I'UK.
United States Patent U.s. cl. 84-1.06 12 claizs ABSTRACT OF THE DISCLOSURE A microphone is shock-mounted in the lower end portion of each tubular resonator to amplify the sound when the coordinating tone bar is struck with the usual vibraharp mallets. A sgnificant objective is to generate amplification at the locale where the tone Waves are known to be true and resonant. 'By employing a full range of enclosed shock-proof microphones and wiring the same to a system-matched amplifier, the desired high fidelity output is achieved. Each baffle-supported microphone (or cartridge) can be tuned to its companion resonator. A fixed resistor is located in between each resonator. The lead wires are protectively encased in diagonal channel bar supported on the resonating tubes.
This invention relates to certain new and useful sound pickup and amplification means functionally and structurally such that it is uniquely adapted for use in conjunction with mallet-type percussion instruments such as, for example, vibraharps, vibraphones, marimbas, xylophones and the like and pertans, more particularly, to balanced amplification of sound expressly engineered to enable each performer to achieve tonal dimension in sound of astounding quality but which is controllable at will by reason of the fact that each sound detecting and pickup means, microphone, cartridge, or audiosensor) is confined for individual response in the sound wave column of each tone bar resonator.
As is known to persons conversant with mallet instruments, when a wooden or metal tone bar is struck with a mallet it vibrates at the frequency to which that tone bar has been tuned. Each tone bar is provided with a tube of prescribed length and cross section which constitutes and provides a compam'on resonator or mechanical amplifier and yields the amplitude desired for its basic or primary tone. The sound Waves are set into motion by strikng a given tone bar and they pass downwardly into the air column (one which is proportional and tuned to the tone baris frequency) and then ascend to produce the amplified sound effect desired. The hardness or softness of the mallet and intensity of the blow determines largely the relative dominance of the fundamental as well as partials in tonal response attained. As is also known, whatever the dynamic tonal output of a tone bar, the timbre and quality is best attained at or near the bottom of the resonator where projection begins. It follows, as will be hereinafter clarified, that an essential or key theme of the instant concept is to generate amplification at the bottom or locale where the tone Waves are rchly resonant and truest.
Briefiy, each resonator is equipped with a highly sensitive shock mounted pickup or microphone which is individually balanced to the harmonic content and dynamic range of the tone bar which it serves. This innovation results in a significantly unique quality system which amplifies the pure tone of the oriented tone bar with clarity and tonal fidelity minus distortion of the ever important primary tones emanating from the tone bars. Individually tuned resonator tubes transmit the primary tonal output of the tone bars to the pickups of microphones via the soundwave air columns. By using a full keyboard range of microphones which are shockproof and are also isolated from the underlying seating and mounting means therefor and the encompassing walls of the resonating tubes, strong, clear tones emanating from a remote controlled high fidelity speakeramplified unit can be and are had.
In carrying out the principles of the present invention each resonator and its Companion self-contained pickup is provided with a complemental resistor Wired to a common input conductor leading to a speaker-amplifier unit with the result that each resonator of the over-all assembly constitutes and provides a critically balanced component of a reliably desirable sound detecting component or system much to the liking of the performer and approval of members of the listening audience.
Novelty is predicated on a structural arrangement and combination of the above briefly described Character and also wherein a simple and practical channel bar is provided and exteriorly diagonally supported from the tubular resonators or in some other convenient manner with the closed channel thereof arranged to accommodate and shieldingly protect the resistors and wiring leading to a conveniently controllable switch having a cable which in practice is operatively connectable, not shown, with an appropriately balanced and constructed portable amplifier.
These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:
FIG. 1 is a view in perspective of a mallet type musical instrument, a portable vibraharp, for example, showing the customary tone bars and resonators, illustrating the control switch at the upper right-hand corner, the conductor or Wire which is adapted to lead to a systemmatched amplifier unit (not shown) and the diagonally arranged channel-Shape member or bar in which the impedance resistors and wires leading from the pickups in the resonators to the switch are contained (not detailed).
PIG. 2 is an enlarged fragmentary view in section and elevation showing the construction of the lower or bottom portion of a typical resonator with its selfcontained microphone taken approximately on the plane of the Vertical section line 2-2 of FIG. 1.
PIG. 3 is a horizontal section taken on the plane of the section line 3-3 of FIG. 2.
FIG. 4 is a view in perspective of one of the aforementioned audosensors, more particularly, a conventional or shock mounted microphone, the seating or supporting baflie therefor, the associated impedance resistor, and adapter grommet therefor.
As will be doubtless clear from the description thus far given, the present concept has to do, broadly speaking, with musical instruments which have come to be known in a general way as mallet instruments, particularly those having mechanical amplifiers to audibly strengthen primary tones and which are referred to as vibraharps, vibraphones, marimbas and xylophones. In these instruments the sound Waves from the tone struck bar or bell are directed and passed downwardly into a tubular air column which is properly proportioned as to bar frequency and which defines a resonator. With reference to FIG. 1, the yibraharp there shown is denoted, generally speaking, by the numeral 6 and comprises a stand having a horizontal top frame structure 8 supported by Vertical legs or equivalent uprights 10 and 11. There is a suitable brace 12 between the lower portions of the uprights and the uprights are provided with rollers, casters or the like for portability as denoted at 14. The tone bars are arranged in rows and are parallel to each other and in a common plane as usual. Those at the rear or top A in FIG. 1 are denoted by the numeral 16 and those at the front or bottom are denoted by numeral 18. In practice, each tone bar is provided therebeneath and in alignment therewith with a resonating tube. When a suspended tone bar (not detailed) is struck with a mallet the tone bar vibrates at a frequency to which it is carefully tuned. The response consists of a fundamental tone and a partal series which collectively determine the individual tone color and pitch of the given tone. In the present disclosure and for simplicity only one resonator is detailed. It should be understood, however, that each resonator is the same in construction, that is, the same as the one detailed in FIGS. 2 and 3. With respect to FIGS. 2 and 3 in particular it will be noted that the tubular resonator is denoted by the numeral and all of the others (which are to be correspondingly constructed in actual practice) are distinguished, merely for convenience, by the numeral 22. These resonators decrease progressively in length from left to right in FIG. l. It is well settled that whatever the dynamic tonal output of a selected tone bar, the output is amplified and developed at the bottom 24 (FIG. 2) of the resonating tube or alternatively, the air column 26- therein.
It is at this point that the electro-mechanical amplification means is introduced. Broadly, the means utilized to attain the end result desired comprises a microphone customarily referred to as a pickup 28 (but also referred to in the trade as an under-bar detecting audiosensor). This pickup 28 can be adjustably supported in the lower column area 24 preferably by way of an adjustably mounted shock minimizing bafile 30. This baffie comprises a suitably dished plate or disk 32 having a marginal dependent flange 34 fitted frictionally but adjustably into the interior of the resonating tube. Each microphone is provided on its bottom with a suitably attached insulating shock absorbng pad 36 and likewise with a similar cushioning pad 38 at the top. The thus constructed microphone is isolated with requisite nicety from the mounting baffle 30 and also the encompassing wall portion of the resonating tube 20. Wires 40 and 42 are operatively wired to the pickup 28. These wires are properly and electrically connected with a companion and complemental resistor 44 which serves to provide the desired prescribed but variable impedance required for each pickup. A grommet 46 is mounted in an opening in the wall of the tube 20 and allows for exit of the wires and the placement or location thereof in channel portion 48 (FIG. 3) of an elongated upwardly angled channel bar 50. This bar 50 has its flanges suitably joined to the exterior bottom portions of the respective resonating tubes. It extends diagonally from left to right (as shown in FIG. 1) where it is then appropriately cooperable with a control switch 52 suitably mounted on the frame and having a conductor 54 connected thereto which in practice leads to a suitable amplifier-speaker unit (not shown).
Each shock mounted pickup is individually balanced to the harmonic content and dynamic range of the resonator bar which it serves. The resonators are individually tuned to each bar and utilized as acoustic filters in transmitting the primary total output of the bars to the enclosed shock mounted pickups. The pickups are Wired through grommets or other suitably lined openings in the resonators in order to provide a critically balanced structure wherein each tone bar 18, associated resonator 20, shock mounted pickup 28 and interconnected resistor 26 constitutesa simple sound detecting system.
In practice the resonator herein shown and described is one of thirty-seven used on a conventional-type vibraharp. 011 other mallet instruments the number of resonators and tone bars varies but is of no patentable significance insofar as the essence of the concept is concerned. The placement of the crystal cartridge or pickup is important in that each is tuned to the resonator and in between each resonator there is an impedance resistor so that actually there are thirty-seven resonators each with a pickup therein and each having a coordinating resistor. Lead wires are encased in the channel and no wires are seen inasmuch as a common conductor (not detailed) is also housed in the channel bar. The bafile itself becomes a tuning baflle in that the length of the air column can be shortened or lengthened to achieve the best tone and sound results.
It is submitted that careful consideration of the specification in conjunction with the views of the drawing will enable the reader to obtain a clear and comprehensive understanding of the invention and therefore, a more eX- tended description is regarded as unnecessary.
The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes vwill readily occur to those skilled in the art, it is not desired to limit the invention to the eXact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention as claimed.
What is claimed as new is as follows:
1. A percussion-type musical instrument, a vibraharp for example, comprising, in combination, a portable stand provided With rows of individually graduated parallel coplanar tone bars adapted to be struck, as usual, with a mallet, individual resonators suspended beneath and communicatively oriented with their respectively coordinated tone bars, said resonators being individually tuned to coincide with Companion tone bars and serving as acoustic amplifiers to strengthen the primary tones emanating from 'said tone bars in |keeping 'with the required air column dimensions and tone bar frequencies, a sound wave pickup microphone operatively mounted in at least one resonator, said microphone constituting and providing an audiosensor and said one resonator functioning to direct and transmit the tonal output of the associated tone bar to said audio'sensor and causing the latter to respond.
2. The structure defined in claim 1, and wherein said pickup microphone is precision-made and balanced to coordinate =with the harmonic content and dynamic range of t-he bar and the entrapped air column it is adapted to serve.
3. The structure according to claim 2, and wherein said microphone is shock-mounted and thus isolated from its mounting means and also isolated from the encompassing vibratory wall portions of the coordinated encompassing resonator.
4. The structure defined in claim 3, and, in combination, a resistor cooperatively associated with and wired to `said microphone, said resistor being possessed of the degree of impedance prescribed for said microphone, whereby said resonator and its complemental microphone constitute a critically balanced individual sound detecting system capable of and adapted for connection with an input conductor leading to a remote Controlled sound amplifying speaker unit.
5. The structure defined in claim 4, and wherein the mounting means for said microphone is adjustably mounted in the bottom portion of said one resonator and is susceptible of being manually adjusted to effect and assist in varying and acoustically tuning the effective length of the air column of said resonator.
6. The structure defined in claim 4, and wherein the mounting means for said microphone comprises a disklike baffle atop which the microphone is seated and from which it is isolated by a shock-absorbing pad, said baflle having a depending marginal flange fitting frictionally Lbut adjustably in the bore of said one resonator.
7. For use on a mallet musical instrument such as for example, a vibraharp, vibraphone, marimba, xylophone or the like, a tone amplifying and resonating tube of predetermined length and cross-'section adapted to be suspended below and communicatively associated with a tone bar of a given frequency, a sound wave pickup microphone made and balanced in keeping with the air column dimension required in Said tube, said microphone constituting and defining an audiosensor for the sound Waves which are trapped for acoustic amplification in said tube, and means for removably and adjustably mounting said microphone in said tube.
8. The structure defined in claim 7, and Wherein said pickup microphone is precision-made and balanced to coordinate with the harmonic content and dynamic range of the bar and the entrapped air column it is adapted to serve.
9. The structure as defined in claim 8, and, n combination, a resistor cooperatvely associated 'with and Wired to said microphone, said resistor being possessed of the degree of irnpedance prescribed for said microphone, whereby said resonator and its complemental microphone constitute a critically balanced individual sound detecting system capable of and adapted for connec'tion with an input conductor leading to a remote controlled sound amplifying speaker unit.
10. In a percussive mallet-type musical instrument, a vibraharp, vibraphone, marimba or xylophone for example, a portable stand provided with a plurality of rows of individually graduated parallel coplanar tone bars arranged and adapted to be struck and lset into vibration with a mallet, individual tubular resonators supported and suspended beneath and communicatively oriented with each tone bar, the air column of each resonator being individually tuned to the bar it serves and constituting an acoustic amplifier to strengthen the prirnary tones emanating from the associated bar, a supporting and tuning bafile comprising a dished plate having a marginal fiange frictionally fitted in a lower portion of the cooperable resonating tube, and a shock-proof microphone mounted atop said baflle.
11. The musical instrument defined in and according to claim 10 wherein each resonator is provided with an individual resistor Wired to its coordinated and oriented microphone.
12. The musical instrument defined in and according to claim 11, and, in combination, an elongated channelshaped bar having its open side facing said resonators With its flanges joined to coacting surfaces of said resonators, said channel-shaped bar being inclined diagonally from the resonators at one end to the resonators at the other end, the channel portion constituting a housing and the resistors and wiring being housed and shielded in said channel.
References Cited UNITED STATES PATENTS 2,413,062 i 12/ 1946 Miessner 84 1.15 2,553,927 5/1951 Maas 84 1.14 3,01l,38l 12/1961 Monfelt 84-376 3,229,021 1/1966 Baschet 84-1.l4 3,301,118 1/1967 Keane et al. 84-1 3,454,703 7/1969 Rose 84-1.15
WARREN E. RAY, Primary Examiner U.S. Cl. X.R. 84-114