GB2038069A - Stringed musical instrument - Google Patents

Abstract

The body 1 of the instrument, eg a double bass, is of narrow elongate shape and is divided into two resonating chambers 13, 14 of unequal size by a sound-beam 11 extending across the whole width of the body 1. The chambers 13, 14 are connected by at least one hole 15 extending through the sound- beam 11. The bridge 9 is supported on the frontplate 2 at the position of the sound-beam 11 and is in contact with an electrical pick- up 20. The volume ratio of the two chambers 13, 14 is preferably between 1:2 and 1:3, eg 2:5 for a double bass, with the chamber 13 nearer the neck being the larger. <IMAGE>

Description

SPECIFICATION Stringed musical instrument The invention relates to a stringed musical instrument, in particular (but not solely) a double bass, of the type comprising a resonating body formed by a frontplate, backplate and side ribs, a neck secured to the body, a bridge supported on the front-plate, and strings extending along the body and neck and stretched across the bridge. More particularly, the invention relates to such a stringed musical instrument having an electrical pickup element mounted between the bridge and a part of the body for connection to an electrical amplifier and loudspeaker system.

The use of an electrical pick-up element in a stringed musical instrument having a body or resonating box of conventional form and design leads in many cases not to a satisfactory result because certain overtones and parasitic vibrations are unequally amplified. This is particularly the case in a double bass, which instrument often has a strong tendency to produce certain relatively weak or relatively strong notes, which cases an unbalanced sound and may lead to reaction coupling effects.

An object of the invention is the provision of an improved stringed musical instrument of the above-described type which at least substantially obviates these draw-backs and, apart from this, presents further advantages as mentioned below. The invention is applicable to stringed musical instruments in general, such as violins, cellos, and guitars, but has been found to be particularly advantageous in the case of a double bass.

The invention provides a stringed musical instrument which has a body of narrow elongate shape and comprises a transverse soundbeam arranged in the body dividing the latter into two separate resonating chambers of unequal size which sound-beam extends across the whole width of the body between the side ribs thereof and fittingly engages the inner sides of the frontplate and backplate of the body, said sound-beam having at least one hole formed therein extending in the longitudinal direction of the body to connect said two resonating chambers, the bridge being supported on the front-plate at said sound-beam.

It has been shown that a stringed musical instrument having a body of the above-described structure makes it possible to realize balanced amplification of all notes within the complete range of the instrument, allowing notes of exactly the right pitch and the desired strength to be produced without the occurrence of any reaction coupling effects.

The instrument reacts readily, even in the higher ranges of the low strings, as is particularly important for a double bass since conventional instruments of this type often show a dead spot in this range. Another great advantage is that because of the simple shape of the body the instrument can be easily handled and transported, which again is of particular important for a double bass, while furthermore the design of the body allows a relatively sturdy construction whereby the instrument is less vulnerable to shocks and also less sensitive to weather influences.

The ratio between the volumes of the two resonating chambers may lie generally between 1:2 and 1:3, depending on the shape of the body and the type of the instrument; within these limits the best location of the transverse sound-beam can be determined by experiment. For a double bass this ratio is preferably approximately 2: 5.

Preferably, the resonating chamber adjacent the neck of the instrument has a larger volume than the resonating chamber remote from the neck.

The frontplate of the body may be left unperforated in the areas thereof covering the two resonating chambers, whereby the strength of the box is improved. However, it may be required to drill a small hole in one or more locations of the frontplate, to be determined by experiments, if this should appear desirable to improve the sound of certain notes.

According to a preferred embodiment of the invention, the pick-up element is mounted with its upper end against the lower side of the bridge in the middle thereof, the pick-up element extending from the upper end downwardly through a bore formed in the frontplate and in the sound-beam perpendicularly to the frontplate and opening into the connecting hole in the sound-beam, the lower end of the pick-up element finding support in this hole. The pick-up element thus receives vibrations from two sides, that is from the bridge and from the sound-beam arranged between the two resonating chambers. Preferably, a vibration plate is mounted in the sound-beam and extends across the hole therein, the lower end of the pick-up element being supported on the vibration plate.

The pick-up element itself can be of any suitable known design and may comprise a piezo-electric transducer. Because of the sturdy construction of the body of the instrument it is possible to detachably secure the neck of the instrument to the body if this is considered desirable.

In order to allow a double bass according to the invention with its narrow elongate body to be supported against the body of the player, a bow member may be secured to one side of the body of the instrument, which bow member is preferably detachable.

The invention will be further explained, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a front elevation of a double bass; Figure 2 is a side view of the double bass; Figure 3 is an enlarged.cross-section on the line Ill-Ill of Fig. 1; and Figure 4 is, on the same scale as Fig. 3, a longitudinal section at the location of the bridge and the sound-beam.

In the drawings there is shown a double bass having a wooden body 1 comprising a frontplate 2, a backplate 3, and side walls or ribs 4. The body 1 has a narrow elongate shape with longitudinally extending curved ribs, as seen in the front elevation of Fig. 1, the body 1 having its greatest width approximately midway along its iengths and the ribs 4 converging from there towards the upper and lower end of the body. As seen in the side-elevation of Fig. 2, the frontplate 2 and the backplate 3 are slightly curved, the body having the smallest depth at its lower end and the plates 2 and 3 slightly diverging upwardly from that end.As can be seen in Fig. 3, the plates 2 and 3 are straight in cross-section and the ribs 4 extend obliquely downwardly and inwardly from the frontplate 2 to the backplate 3, the body thus having in crosssection the shape of a symmetrical trapezium.

Except for an opening 1 6 as mentioned below, the frontplate 2, like the backplate 3, presents a closed surface. However, it is possible to provide the frontplate 2 with one or more drilled holes (not shown) in suitable locations if this appear to be desirable for improving the quality of certain notes.

A metal support 5 of conventional design is secured to the lower end of the body 1 and a neck 6 likewise of conventional design is secured to the upper end of the body, which parts 5 and 6 may be detachable if so desired for eas of transportation. The strings 7 of the instrument are arranged and attached in the conventional manner and extend along a finger-board 8 secured to the neck 6. The strings 7 are stretched across a bridge 9 having two leg portions 10 which support the bridge 9 on the frontplate 2 of the body 5.

A wooden sound-beam 11 is arranged transversely inside the closed hollow body 1 at the position where the legs 10 of the bridge 9 are resting on the frontplate 2 and where the body 1 has approximately its greatest width. The sound-beam 11 extends across the whole width of the body 1 closely fitting between the opposite side-ribs 4 and between the frontplate 2 and the backplate 3, as shown in Fig. 3. The beam 11 can be secured to these ribs 4 and plates 2 and 3 by fluing.

As seen in the longitudinal direction of the body 1, the thickness of the sound-beam 11 is several times greater than the thickness of the bridge legs 10 (Fig. 4).

The sound-beam 11 thus divides the body 1 into two separate resonating chambers 1 3 and 14, the chamber 1 3 having a greater volume than the chamber 14. For the depicted double bass the ratio between the volumes of the two chambers 1 3 and 14 is approximately 5:2 in which the chamber 1 3 of greater volume is situated at the upper end of the body 1 adjacent the neck 6.

About midway of its length the sound-beam 11 is provided with a hole 1 5 extending in the longitudinal direction of the body 1 and acoustically connecting the two resonating chambers 1 3 and 14.

An opening 1 6 of oval shape has been cut out in the frontplate 2 between the legs 10 of the bridge 9 and the sound-beam 11 has a bore 1 7 in continuation of the opening 1 6.

The bore 1 7 opens into the hole 1 5 and extends approximately up to the axis of this hole. The width of the bore 17, as seen in the cross-section of Fig. 3, is greater than the width or diameter of the cylindrical hole 1 5. A pick-up element 20 of known type comprising a piezo-electric transducer is mounted in the opening between the bridge legs 10 and extends into the bore 1 7. The element 20 has two pointed ends, one of which engages the lower side of the bridge 9 midway between the bridge legs 10 and the other of which engages a vibration plate 1 8 which is mounted at the bottom of the bore 1 7 in a position extending across the hole 1 5. Opposite ends of the vibration plate 1 8 are secured in grooves 1 9 formed in the body of the sound-beam 11.

Although the pick-up element 20 is preferably supported on a vibration plate 18.in the above-described manner, it is also possible to support this pick-up element 20 with its lower end directly on the bottom wall of the connection hole 1 5.

It will be understood that within the scope of the invention as defined in the claims, the shape and design of the body 1 of the instrument can be varied: the correct position of the transverse sound-beam 11 and the ratio of the volumes of the two resonating chambers 1 3 and 1 4 should of course be adapted to the shape of the body and can be further determined by experiment. This is also the case for the size of the connection hole 1 5 providing the acoustical.coupling between the two resonating chambers 1 3 and 1 4.

Other stringed musical instruments, such as cellos, violins, and guitars, can be built according to the same principle as above-described for a double bass; obviously the size and design of the instrument body must be chosen accordingly.

As shown in Fig. 1, a metal bow 21 can be secured to one side of the body 1 which bow is preferably detachable. This bow can be used to support the instrument against the body of the player to hold the instrument in the proper position during playing.

Claims (11)

1. A stringed musical instrument compris ing a resonating body formed by a frontplate, a backplate, and side ribs, a neck secured to the body, a bridge supported on the frontplate, strings extending along the body and neck and stretched across the bridge, and an electrical pick-up element mounted between the bridge and a part of the body for connection to an electrical amplifier and loudspeaker system, the body having a narrow elongate shape, a transverse sound-beam arranged in the body dividing the body into two separate resonating chambers of unequal size, which sound-beam extends across the whole width of the body between the side ribs and fittingly engages the insides of the frontplate and the backplate, the sound-beam having at least one hole therein extending in the longitudinal direction of the body to connect the two resonating chambers, the bridge being supported on the frontplate at the position of the soundbeam.

2. An instrument as claimed in claim 1, in which the ratio between the volumes of the two resonating chambers lies between 1 : 2 and 1 :3.

3. An instrument as claimed in claim 2, being a double bass, in which the ratio is approximately 2 : 5.

4. An instrument as claimed in any of claims 1 to 3, in which the resonating chamber adjacent the neck has a larger volume than the resonating chamber remote from the neck.

5. An instrument as claimed in any of claims 1 to 4, in which the frontplate is unperforated in the areas thereof covering the two resonating chambers.

6. An instrument as claimed in any of claims 1 to 4, in which the frontplate has a hole drilled therein at one or more locations.

7. An instrument as claimed in any of claims 1 to 6, in which the body has in crosssection the shape of a trapezium.

8. An instrument as claimed in any of claims 1 to 7, in which the pick-up element is mounted with its upper end against the lower side of the bridge in the middle thereof, the pick-up element extending from the upper end downwardly through a bore formed in the frontpIate and in the sound-beam perpendicularly to the frontplate and opening into the connecting hole in the sound-beam, the lower end of the pick-up element being supported in this hole.

9. An instrument as claimed in claim 8, including a vibration plate mounted in the sound-beam and extending across the hole therein, the lower end of the pick-up element being supported on the vibration plate.

10. An instrument as claimed in any of claims 1 to 9, in which the neck is detachably secured to the body.

11. An instrument, as claimed in any of claims 1 to 10, including a bow member secured to one side of the body.

1 2. An instrument as claimed in claim 11, in which the bow member is detachably secured to the body.

1 3. A stringed musical instrument substantially as described herein with reference to, and as shown in, the accompanying drawings.