WHY THIS DESIGN the IBS System (introduction)
Traditionally a lot of attention has been given to the selection of timber, for guitar building using the tap tone selection method; in the hope of producing an exceptional sounding acoustic guitar. This process is explained in the Introduction of Tech Info. But all too often the guitar that is produced, is lacking in the tonal qualities first sought after by the tap tone selection process. While a lot of consideration is also given to the sizing and placement of braces within the X-braced soundboard, very little consideration is given to the stress placed onto the soundboard.
As you may well imagine the load tension of steel strings' placed onto the bridge of a very thin (2.5 mm) wooden soundboard without support, would be destructive. In fact some 730 Newtons (an equivalent weighted mass of about 74 kg) are in effect. Surprisingly enough soundboards are not directly supported against this string load tension; they are simply braced underneath to stop them from buckling up, to much. The X-braced guitar has such a guitar bracing system and it is the industry standard, for an acoustic steel string guitar. The reason for such a simple design with due disregard of the string load tension, is to gain high sound volume levels, from the soundboard of the guitars . But this comes at the expense of a lack of sustained string vibration -- where the sound fades away quickly -- and all to often demonstrates dead notes, when trying to play a slow melody. Further the resulting shorter lived louder sound demonstrates untrue harmonics and tonal loss!
Sustained string vibration does not only give a prolonged sound; it also provides many other feature qualities in the production of a musical sound. A full rich tone comes from a sustained vibrating string; the rich tonal sound is made by providing extra and truer audible harmonic content, with depth. A wooden soundboard is only going to reproduce sound by its own limits to do so and from the vibration that affects it. For a full description of the benefits of a sustained vibrating string length, a short list of the benefits is set out below. A more comprehensive list is also provided, in the points of discussion found within the first pages of Tech Info.
Indirect Bracing Structure (IBS) System Soundboard
Looking at Fig 1 shows a basic drawing of the central area of my Indirect Bracing Structure (IBS) System. This system which indirectly supports the string load tension has enabled me to resolve the short comings and compromises, that has been evident in the x-brace guitar (as discussed in the OVERVIEW and above).
Two blocks 3 & 4 are positioned each with one of their sides located under the bridge. From these sides, the static string load tension is upheld and redirected to points (A), found on braces 1 & 2. The static load tension of the strings is divided in two parts; supported by the treble block 3 and bass block 4. An important feature of this system, is the way the static string load tension has been taken at an acute angle (ω); as indicated by the dashed lines seen in Fig 1. When one or more strings are set to vibrate, the transmitted string vibrations travel within the directional pre-loaded path of the dashed lines; towards the reflection point(s) (A). Due to the location of reflection points (A), outside of the string line area, string vibrations are efficiently redirected and are then able to reflect at an angle (other than 90 deg) throughout the soundboard.
Further to the central bracing system, soundboard transmitting braces are placed in favourable calculated positions, and there by evenly distribute the reflected string vibrations throughout the soundboard of the IBS System. The IBS System is not only structured to support the static string load tension, but in itself is dynamic. The dynamics involving the functional blocks and braces, to support, reflect and or to transmit the motion of vibration, share many combined features. Such as their altogether locations and work ability. The angles that are taken, sizing and dimensionality are all mathematically interrelated and balanced, using known scientific principles.
The X-brace in comparison
The Indirect Bracing structure (IBS) System can comfortably withstand the split load of ~74kg, each side of the soundboard. The sound board is so well supported, that if you were to remove the back from this guitar with the strings fully tuned up, the guitar body sides and soundboard would not buckle up and break... In fact you would still be able to play it! If you were to try and do this with a conventional industry standard x-braced guitar, you could very well imagine the consequences; the soundboard, x-brace and sides of the body would all buckle up and break.
The IBS System guitar soundboard is so well relieved from stress, that its rise as seen just behind the bridge area is near flat, showing a rise of only about 0.5 mm. In comparison, take a good side on look at the surface area of the soundboard of an X-braced industry standard guitar, they usually have a 3 mm + rise behind the bridge area.
The above discussion shows that the IBS System Soundboard, is left in its original natural state; free of stress and most importantly pre-tension and therefore, is able to vibrate uniformly. Vibrations travelling along the plane area of the soundboard do not encounter any pre-stressed resistance, areas. The soundboard is thus able to vibrate the air inside the guitar body where reverberation of airwaves takes place uniformly. Air waves moving in and out of the sound hole are the sound sauce, for the projection of soundwaves through the air. The beam of soundwave projection, from the sound hole of the IBS system, is uniformly straighter and so travels efficiently further.
In contrast, a soundboard like the x-braced soundboard wavers with vibration more so longitudinally (in the string line direction), than it does transversely or perpendicular to its face. Air waves projecting from its sound hole become scattered and therefore, form into a defused cloud of sound, around the player.
Traditionally a lot of attention has been given to the selection of timber, for guitar building using the tap tone selection method; in the hope of producing an exceptional sounding acoustic guitar. This process is explained in the Introduction of Tech Info. But all too often the guitar that is produced, is lacking in the tonal qualities first sought after by the tap tone selection process. While a lot of consideration is also given to the sizing and placement of braces within the X-braced soundboard, very little consideration is given to the stress placed onto the soundboard.
As you may well imagine the load tension of steel strings' placed onto the bridge of a very thin (2.5 mm) wooden soundboard without support, would be destructive. In fact some 730 Newtons (an equivalent weighted mass of about 74 kg) are in effect. Surprisingly enough soundboards are not directly supported against this string load tension; they are simply braced underneath to stop them from buckling up, to much. The X-braced guitar has such a guitar bracing system and it is the industry standard, for an acoustic steel string guitar. The reason for such a simple design with due disregard of the string load tension, is to gain high sound volume levels, from the soundboard of the guitars . But this comes at the expense of a lack of sustained string vibration -- where the sound fades away quickly -- and all to often demonstrates dead notes, when trying to play a slow melody. Further the resulting shorter lived louder sound demonstrates untrue harmonics and tonal loss!
Sustained string vibration does not only give a prolonged sound; it also provides many other feature qualities in the production of a musical sound. A full rich tone comes from a sustained vibrating string; the rich tonal sound is made by providing extra and truer audible harmonic content, with depth. A wooden soundboard is only going to reproduce sound by its own limits to do so and from the vibration that affects it. For a full description of the benefits of a sustained vibrating string length, a short list of the benefits is set out below. A more comprehensive list is also provided, in the points of discussion found within the first pages of Tech Info.
Indirect Bracing Structure (IBS) System Soundboard
Looking at Fig 1 shows a basic drawing of the central area of my Indirect Bracing Structure (IBS) System. This system which indirectly supports the string load tension has enabled me to resolve the short comings and compromises, that has been evident in the x-brace guitar (as discussed in the OVERVIEW and above). Two blocks 3 & 4 are positioned each with one of their sides located under the bridge. From these sides, the static string load tension is upheld and redirected to points (A), found on braces 1 & 2. The static load tension of the strings is divided in two parts; supported by the treble block 3 and bass block 4. An important feature of this system, is the way the static string load tension has been taken at an acute angle (ω); as indicated by the dashed lines seen in Fig 1. When one or more strings are set to vibrate, the transmitted string vibrations travel within the directional pre-loaded path of the dashed lines; towards the reflection point(s) (A). Due to the location of reflection points (A), outside of the string line area, string vibrations are efficiently redirected and are then able to reflect at an angle (other than 90 deg) throughout the soundboard.
Further to the central bracing system, soundboard transmitting braces are placed in favourable calculated positions, and there by evenly distribute the reflected string vibrations throughout the soundboard of the IBS System. The IBS System is not only structured to support the static string load tension, but in itself is dynamic. The dynamics involving the functional blocks and braces, to support, reflect and or to transmit the motion of vibration, share many combined features. Such as their altogether locations and work ability. The angles that are taken, sizing and dimensionality are all mathematically interrelated and balanced, using known scientific principles.
The X-brace in comparison
The Indirect Bracing structure (IBS) System can comfortably withstand the split load of ~74kg, each side of the soundboard. The sound board is so well supported, that if you were to remove the back from this guitar with the strings fully tuned up, the guitar body sides and soundboard would not buckle up and break... In fact you would still be able to play it! If you were to try and do this with a conventional industry standard x-braced guitar, you could very well imagine the consequences; the soundboard, x-brace and sides of the body would all buckle up and break.
The IBS System guitar soundboard is so well relieved from stress, that its rise as seen just behind the bridge area is near flat, showing a rise of only about 0.5 mm. In comparison, take a good side on look at the surface area of the soundboard of an X-braced industry standard guitar, they usually have a 3 mm + rise behind the bridge area.
The above discussion shows that the IBS System Soundboard, is left in its original natural state; free of stress and most importantly pre-tension and therefore, is able to vibrate uniformly. Vibrations travelling along the plane area of the soundboard do not encounter any pre-stressed resistance, areas. The soundboard is thus able to vibrate the air inside the guitar body where reverberation of airwaves takes place uniformly. Air waves moving in and out of the sound hole are the sound sauce, for the projection of soundwaves through the air. The beam of soundwave projection, from the sound hole of the IBS system, is uniformly straighter and so travels efficiently further.
In contrast, a soundboard like the x-braced soundboard wavers with vibration more so longitudinally (in the string line direction), than it does transversely or perpendicular to its face. Air waves projecting from its sound hole become scattered and therefore, form into a defused cloud of sound, around the player.
A more in depth technical discussion with diagrams, about all these subjects may be found in Tech Info.
The performance of the IBS System Guitar is clearly illustrated in the Specifications link found at the bottom of this page.
The performance of the IBS System Guitar is clearly illustrated in the Specifications link found at the bottom of this page.
BENEFITS of the IBS SYSTEM
The Indirect Bracing Structure IBS System is able to reproduce a full rich musical sound. From the strings that efficiently vibrate the soundboard, through to the body that projects the soundwaves. With true tonal sustain of combined sinewaves, the benefits are as follows:
The Indirect Bracing Structure IBS System is able to reproduce a full rich musical sound. From the strings that efficiently vibrate the soundboard, through to the body that projects the soundwaves. With true tonal sustain of combined sinewaves, the benefits are as follows:
- Normal sound volume levels, with lasting clean crisp notes; enables a slow melody to be audible;
- Tonal sustain, with true overtones relative to the fundamental, having higher amplitudes more closely related to a fixed-fixed string length;
- Extra audible harmonic content is included in the complex musical tone, producing a rich full musical sound;
- a well balanced string range, extending all the way up the neck;
- an appreciable reduction in sympathetic string vibration, due to the built-in buffing action;
- A 3 x simultaneous string note mixing action smoothes out and combines the overall sound, of chord structures.
See the Tech Info pages for an in-depth discussion on harmonics and my IBS System.
SPECIFICATIONS: IBS System vs X-brace: dB graphs compare both systems over a period of time, to show Sound-Intensity-Levels.