Round sound holes centered near the waist of acoustic guitars have been the standard since before Torres. The main alternative we’re all familiar with are the f holes of archtop guitars, borrowed by Gibson from the design of orchestral stringed instruments. But why have holes at all? Do we need them for the sound to get out? Not exactly. Most of the sound comes from the top of the guitar. If you block the sound hole, there is only a slight change in the sound.
The answer is complex and involves physics. Physics is not my area of expertise but my layman’s understanding is essentially that the air movement inside the guitar can either deaden or reinforce the vibrations of the top. The size, shape and placement of the sound hold can thus effect wolf tones, clarity and balance. Larger sized holes can increase mid tones. But perhaps the most important things to remember is this is a complex topic; luthiers experiment more by instinct or trial and error than by physics; and in the end the results are subjective. Do you like the sound?
I think the physics of guitars is interesting but for the most part, I’m going to just review some of the variations in sound hole design that are being used today. A good review of sound hole alternatives was published in Acoustic Guitar in 1999 is reproduced at thatauthors website.
Standard round holes
The size and shape and location of the guitar sound hole has been fairly constant for hundreds of years. The classical guitar shown here is typical of classical and steel string acoustic guitars.
Larger than standard sized holes
Enlarging the sound hole can reduce the wolf tones and make for a better recording guitar Tony Rice is one of the artists who endorses this concept. Martin has made a “D” sized guitar with this feature. It’s designation is the HD-16R LSH. The “LSH” stands for “Large Sound Hole”.
F holes
Gibson invented the archtop guitar and soon after that added f holes to that design. You can still buy archtop hollow body guitars with f holes but if you want a purely acoustic instrument there are fewer choices. Godin, The Loar and others make affordable, non-cutaway f hole guitars but all acoustic f hole models (no pick ups) are rarer now days. The image below is the Gibson ES-150 also known as the Charlie Christian model.
Oval holes
There are two popular variations of the guitars favored for Gypsy jazz guitar. Among the most noticeable differences are the shape of the sound hole. The guitar pictured below has a small length-wise oriented oval sound hole. This is referred to as thePetite Bouche or “small mouth”. This design was originally made by the Selmer company and made famous as the guitar played by Django Reinhardt.
D holes
The famous guitar designed byMaccaferrifor Selmer is sometimes called the “grande bouche” or big mouth. The guitar has a large “D” shaped sound hole.
Triangular holes
I remember Pete Segar played a guitar with an odd, almost triangular sound hole. Gretsch has made several acoustic guitars with a similar sound hole. Below is one of their Rancher models which is still available.
Offset holes
Ovation was one of the first guitar makers to experiment with offset sound holes. These originally appeared in their Adamas carbon fiber topped line. Ovation (now owned by Fender) still has guitars and mandolins with epaulets over multiple sound holes.
Side ports
Sound holes in the side of the guitar instead of, or more likely in addition to holes in the top are another feature that is gaining popularity. Luthier Alan Curruth has experimented with side ports. It is unclear if the sound heard by an audience is improved or not with side ports, but the clear advantage of side ports in acoustic instruments is they serve as a personal monitor allowing the instrument player to better hear what they play.
I couldn’t find any big online retailers selling acoustic guitars with side ports but these are also seen on ukuleles from Riptide (and other more expensive makes). Riptide is made by Boulder Creek who also makes guitars with side ports – too bad the online merchants don’t carry their guitars.
More Examples of Sound Hole and Port Design can be found on my Pinterest Board “Sound Holes and Ports“.
FAQs
Sound emanates from the surface area of the sounding boards, with sound holes providing an opening into the resonant chamber formed by the body, letting the sounding boards vibrate more freely, and letting vibrating air inside the instrument travel outside the instrument.
What does a sound port do? ›
It helps get the sound from the strings more directly to your ear.
How do the holes affect the sound of a flute? ›
Opening tone holes
If you open the tone holes, starting from the far end, you make the pressure node move closer up the pipe - it's rather like making the pipe shorter. On the Boehm flute, each opened tone hole raises the pitch by a semitone.
What is the function of the sound hole on a guitar? ›
The sound hole enhances the radiation of sound by vibrating the volume of air inside as well as near its opening.
How does sound do work? ›
Sound is a type of energy made by vibrations. When an object vibrates, it causes movement in surrounding air molecules. These molecules bump into the molecules close to them, causing them to vibrate as well.
Do sound hole covers work? ›
However, with the soundhole sealed up, the internal air spring restricts the top and back's free movement. This is why soundhole plugs help reduce feedback—they harness the captive air inside the guitar as a tool to reduce the top's ability to vibrate.
What does audio out port do? ›
The motherboard of a machine has an audio port. This port is used to connect audio devices like speakers, microphones, and home theater systems. The audio port is only functional when a device is connected through an electrical connection or cable. Audio port are required when using Bluetooth technology.
What is the sound port called? ›
The intended application for a phone connector has also resulted in names such as audio jack, headphone jack, stereo plug, microphone jack, aux input, etc. Among audio engineers, the connector may often simply be called a quarter-inch to distinguish it from XLR, another frequently-used audio connector.
What port is used for audio? ›
The port is a 3.5mm stereo jack socket suitable for use with the most standard audio leads and connection to the 'headphone' output socket of most audio systems.
How do tone holes work? ›
Simple Explanation:
Tone holes work by effectively shortening the vibrating length of the tube. If you recall from Pipe Lengths, the longer the pipe, the lower the pitch. And the shorter the pipe, the higher the pitch.
Open-hole flutes, sometimes called French-model, have holes in the keys which are covered by the flutists' fingers. This allows for a greater range of fingerings and playing techniques, as well as an improved tone. However, it also means that the player must be more precise with their finger placement.
How do the holes on a recorder work? ›
The holes are not in a straight line because they are positioned so as to be easier to cover with the fingers. In fact, providing they are positioned at the same height in the bore, the same pitch of sound will be produced irrespective of where they are placed on a circumference of the bore at that height.
What do sound holes do? ›
Sound-hole, an essential component of stringed musical instruments, enhances the sound radiation in the lower octave by introducing a natural vibration mode called air resonance.
What is the best soundhole shape? ›
A study by acoustic engineers from MIT revealed that an f-shaped hole increases the power of sound and enhances the tone a lot more than other types of sound holes.
What is the f-hole on a guitar for? ›
The real purpose of the f-hole on a Thinline Telecaster
“On hollow instruments with an f-hole, the motion of the bridge is driving the top, and the f-hole's size and shape affects the resonance and overall tone of the instrument,” he explains.
How do black holes affect sound? ›
The sound required a lot of “bumping up.” The “note” emitted by the black hole was increased by 57 octaves in order to make it audible to the human ear. “For reference, the A in the middle of the piano is 440 cycles per second, and this [sound] is one cycle per 10 million years,” Blazek says.
What does the hole in a speaker do? ›
As with most things engineering the hole has specific qualities to tune what comes out of the hole and what sound the speaker produces. If done properly, the pressure exhausting the port both adds to the bass as well as enables the woofer to breathe a bit easier.
Do f-holes make a difference? ›
The sound on guitars with F-holes is clearer. Notes sound slightly more separated and distinguished when compared to a round hole guitar. The position and shape of the sound hole seem to have a reducing effect on the resonance, which leads to a decreased overlap of notes, adding to the clarity of the sound.
What is the purpose of an f-hole? ›
The openings on both sides of the body of the violin that are shaped like a lowercase "f" are appropriately called f-holes, and these serve to transmit to the outside air the vibrations within the body caused by the body's resonance, ringing out with a rich tone.
