Patent Application
20240233686
The present disclosure relates to devices that enhance the tone of musical instruments and, more specifically, to a device that reduces unwanted overtones and reverberation caused by reflected sound inside the tone chamber of an open back banjo or resonator banjo pot.
Open back banjos are used primarily to play old-time music and are configured differently from resonator banjos, used primarily to play bluegrass music. Whereas a resonator banjo will most often be set up with a high head tension, open back banjos generally use lower head tension to mellow the tone and enhance the instrument's bass response—often referred to as a “plunky” sound.
The banjo's circular tone chamber creates enhanced opportunities for reflected sound inside the banjo's pot. In this context, reflected sound is referred to as sound produced as a by-product of the fundamental sound created by the transference of energy from a vibrating string through the bridge and on to the banjo head. Reflected sound is most often perceived as undesirable overtones and/or reverberation which has the effect of muddying the banjo's tone, reducing note clarity and articulation.
It is common practice for many old-time banjo players to “stuff” their banjo pot by placing a soft, flexible object between the banjo head and the dowel stick or coordinator rod(s). The object exerts direct pressure on the banjo head, dampening the head's vibrations in an effort to attenuate unwanted overtones/reverberation. Some example materials used are foam rubber, rolled towels, rolled rags, socks, felt pads and even small stuffed toys. Unfortunately, these methods have the unwanted side effects of reducing both the banjo's bass and treble response as well as a noticeable reduction in volume, resulting in an overly compressed and flattened sound.
The present invention solves these problems by providing a dampener formed as a cylindrical shell that is filled with polyester fibers and dimensioned to match the inner art of the banjo rim and be positioned therein. The dampener attenuates unwanted overtones/reverberation while preserving the all-important fundamental sound with minimal reduction in bass, treble and volume. By treating the banjo's tone chamber as an acoustic space and focusing on dampening reflected sound, the present invention functions as a sound absorber, designed specifically to remove unwanted sonic energy from the sound chamber caused by reflected sound. The present invention is further designed to allow the user to easily adjust the amount of overtone/reverberation attenuation needed by how the device is positioned inside the banjo, thus providing a wide range of control and customization over their desired tone. The present invention is also designed to be easily inserted and removed from the banjo, as needed, and does not require any alteration to the instrument.
The present invention will be more fully understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which:
Referring to the figures, wherein like numerals refer to like parts throughout, there is seen in
Referring to
Cotton poplin fabric was selected for the outer shell based on its sonic properties as well as its ability to adapt to the shape of the banjo rim and hold the invention's desired configuration while positioned inside the banjo. See Table 1 below for a comparison of different fabrics considered for use in the design of this invention. Table 1 shows a comparison of different fabric and fill types and their effect on volume attenuation, bass attenuation, treble attenuation, overtone attenuation, the adjustability of the invention's position when placed inside the banjo rim, and how well the invention holds its shape after being placed.
Polyester fill was selected based on its sonic properties as well as its ability to adapt to the shape of the banjo rim and hold the invention's desired configuration while positioned inside the banjo. See Table 1 above for a comparison of different fill types explored in the design of this invention.
The amount of polyester fill used is 1.9 grams per inch of length. Alternative amounts were explored in the design of this invention and 1.9 grams per inch was determined to be optimum. Different diameters were also explored in the design of this invention and a size of two inches was selected based on its sonic properties as well as allowing the invention's placement to be easily adjusted while accommodating a wide variety of banjo rim depths.
The present invention is designed to be placed in either the lower or upper, inner arc of the banjo pot, with each end contacting the dowel stick or coordinator rod(s) perpendicularly. The length of the present invention will follow the curve of the banjo rim and make gentle contact with the underside of the banjo head, as seen in
For banjos with Dobson tone rings, or other tone rings that prevent simultaneous direct contact of the present invention with both the banjo rim and head, the invention will be placed on the inner curve of the tone ring and rest against it instead of the rim.
The present invention is designed to be easily adjusted to achieve the desired amount of overtone/reverberation attenuation. This is determined by how much of the present invention contacts the underside of the banjo head and by how much pressure is applied to the head. The present invention is flexible and can be adjusted so that all or none of its length contacts the banjo head. The least amount of overtone/reverberation removal is achieved when there is no contact with the head. In contrast, maximum overtone/reverberation removal is achieved when the entire length of the present invention contacts the banjo head and maximum pressure is applied by pushing the present invention against the head when it is placed inside the banjo. In addition to these two extremes, the present invention can be shaped so that only a portion contacts the banjo head or that most of the present invention contacts the banjo head and only a portion does not. This flexibility allows the user to achieve their own unique tone and maximize the sonic potential of their specific instrument.
This adjustability is also of importance to banjo players who perform in outdoor venues, especially those using hide heads. Temperature and humidity changes can adversely affect the sound of the banjo, making it challenging to achieve the desired tone while playing outdoors. The adjustability of the present invention makes it possible to quickly increase or decrease overtone/reverberation attenuation to efficiently adapt to the musician's playing environment.
The present invention is designed to stay inside the banjo as long as the user desires. Due to the cotton poplin outer shell and precise amount of fill used, it will gently hold its position until manually readjusted or removed. The soft cotton poplin outer shell along with the soft polyester fill assures that the invention will not scratch or damage the banjo in any way.
Table 2 below shows a direct comparison between the present invention and a common form of conventional banjo stuffing—foam rubber. The foam rubber used was 3″×1.5″ and was placed between the dowel stick/coordinator rod(s) and the banjo head, at the neck end of the banjo. The foam rubber size and placement location were found to yield the optimum results.
From this testing, it may be concluded that foam rubber is not as effective as the present invention in attenuating overtones/reverberation. When foam rubber was used there was a noticeable loss of volume, bass response and treble response as compared to the present invention, resulting in an overly compressed and flattened sound. In addition, foam rubber must always contact the banjo head in order to hold its position. As a result, foam rubber does not offer the wide range of adjustability and control over the desired tone as this invention. Further testing was performed using a wide variety of common stuffing materials (as described in the Background of this Invention section) and the results were nearly identical to foam rubber.
In addition to placing the present invention in an inner arc of a banjo rim, a shorter length version measuring between seven and nine inches may be placed between the coordinator rods of the banjo. When using this configuration, the invention will not contact the banjo head or rim and is designed specifically for resonator banjos but may also be used in open back banjos that are equipped with dual coordinator rods.
| Number | Date | Country | |
|---|---|---|---|
| 63479367 | Jan 2023 | US |
