One will notice that traditional acoustic guitars have a rounded hole in the middle called soundhole. Soundhole is the part of the guitar where the air pressure (both inside and outside of the cavity of the guitar) will equalize when the top vibrated by the strings. The sound produced will be muffled when the guitar cavity is a close system.
The size of the soundhole should be big enough to match the air displacement of the guitar volume when it is played. The size of the instrument should be directly proportional to the opening of the sound hole.
Does soundhole needs to be round all the time? The round shape is often chosen for the soundhole because it is an easy design to work with, it allows for easy repair when needed (such as loosed brace or installing a pickup system). If the soundhole is not at the center of the guitar and not rounded, expect the repair bill to be high. Often times, the repair need to remove the hand string entirely to have the full access to the interior of the instrument.
Double Sound Hole
The famous double sound hole was made around 1920 by Francisco Simplicio. He had proved the disadvantage of the traditional sound hole position have weakened the acoustic guitar’s top and the sound it produced. By applying the two sound holes on both sides, the fingerboards will be extended by two octaves and there will be an improved bass range sound.
Repositioning the sound hole on both sides of the fingerboard has an impact on the sound it produced. It can enlarge the vibrating top part of the guitar. With the proportion of the width or length and thickness of the top, the sound may become:
- In some level, You’ll notice the flexibility of the top part just like a traditional guitar. Although you can also notice to obtain a high mass of the top surface, thus giving you a way to maintain without loosing the approach and responsiveness.
- It can also increase the volume and responsiveness with control on the sound.
- With this design the Helmholtz frequency can be adjusted in a lower level which can give an impact with regards to the instrument’s tonal character.
Expert Luthiers on Alternative Soundholes
Decades ago, everyone saw the changes on famous design guitar builders like Lloyd Loar, D.F. Martin and more. But you can observe that most people require the centered round sound hole of the top, on the flattop guitars and an f-hole on either side of the bridge on the arch-top guitars.
But this doesn’t stop the experienced and respected Luthiers to continue to gaining experiment with the different soundholes locations of the instruments they are creating. Several manufacturers are embracing these concepts, to give acoustic guitars and basses unique sound holes.
Multple smaller soundhole are often combined with the complex arch-top guitar body can produce a bright and clear sound.
The “Paisley” soundhole, developed by Tacoma Guitars. They put the soundhole on the left side of the higher part of their “Wing Series” guitars, thus requiring less bracing to be able to support the hole design.
Soundpots are the holes placed on the top of the acoustic guitars facing the upward playing position. They support the main soundhole and this will help the players monitor the sound they produce.