Guitar Soundhole Diameter: How It Affects Tone

What is the soundhole diameter?

The soundhole is the round opening in the top of an acoustic guitar, usually located between the bridge and the fretboard. Its diameter is the distance across that opening, measured from edge to edge through the center. While the rosette, the decorative ring around it, can vary in width, the actual hole size is what matters acoustically.

The soundhole is not just a visual detail. It is a critical part of the guitar's air pump system. When you pluck a string, the top vibrates, and the air inside the body moves in and out through the soundhole. That movement projects the sound outward and shapes the tone you hear. The diameter directly affects how easily air can flow through that opening. For more on how body shape interacts with the soundhole, see our guide to acoustic guitar body shapes.

• A larger diameter lets more air move per vibration, which can increase volume and low-end response.
• A smaller diameter restricts airflow, often producing a tighter, more focused sound with less boom.

How soundhole size shapes tone

When the soundhole is larger, the air inside the body is less confined. That generally allows the top to move more freely, which boosts bass frequencies and can make the guitar sound louder and more projective. Many dreadnought and jumbo models use relatively generous soundholes to support their powerful voices. Martin describes these large body shapes as having a 'loud projective tone with strong bass,' and the soundhole is part of that equation. To see a range of full-size guitars with different soundhole designs, check out our best full-size guitars.

A smaller soundhole does the opposite. It slows the air movement and often reduces low-end output while making the midrange and treble more prominent. This is why many parlor and concert guitars, which are already known for balanced and crisp sound, pair well with a more modest opening. The result is a drier, more articulate voice that records well and suits fingerstyle playing.

The effect is subtle, but players who swap between guitars can hear it. If you have ever compared a jumbo to an orchestra model, you already know how body size shifts tone. The soundhole diameter works with the body shape and the top's bracing to define the final character. For a deeper dive into bracing, see our guide to guitar bracing patterns.

Soundhole, body size, and bracing

The soundhole does not act alone. It interacts with the body's depth and width, the top's thickness, and the bracing pattern underneath. A deep-bodied guitar like a dreadnought moves a lot of air, so a large soundhole can reinforce its booming bass. A shallow-bodied guitar, such as a thinline acoustic-electric, may use a smaller hole to keep the sound controlled and avoid muddiness.

Bracing also plays a role. X-bracing patterns, common on steel-string acoustics, support the top while allowing it to vibrate. The soundhole is positioned between the bridge and the neck block, and its size must work with the bracing to avoid weakening the top. A soundhole that is too large for the body can make the top feel floppy and reduce sustain. Each body size typically has a soundhole that complements its design. If you play fingerstyle or in intimate settings, a parlor or concert guitar might be a better match.

When choosing a guitar, consider the whole package, not just the hole. The wood of the top, back, and sides also shapes the sound, as explained in our guide to tonewoods.

Choosing a guitar by soundhole character

If you mostly play with a band or need to be heard without amplification, a guitar with a larger soundhole and a big body will give you the volume and bass you want. These are common in bluegrass, country, and flatpicking. For fingerstyle or home recording, a smaller soundhole often delivers a clearer, more controlled tone that sits well in a mix.

Players who rely on the guitar's natural acoustic sound should prioritize the soundhole size that matches their touch. A heavy strummer might find a large-hole guitar too boomy, while a light fingerpicker can make a smaller-hole guitar sound tiny. The best approach is to play different body sizes and pay attention to how each one responds to your attack. To compare options, browse our best rock and pop acoustic guitars for strumming-friendly models or best travel guitars for compact alternatives.

For travel and practice guitars, where portability is key, the body is often smaller and the soundhole is scaled down as well. These guitars rarely project as much as full-size models, but they still offer a usable voice. If you need a guitar for travel, check models designed specifically for that purpose and compare their tone.

Other factors that work with the soundhole

While the soundhole is important, it is just one element. The wood of the top, back, and sides shapes the overall timbre. Martin's wood guide notes that 'the top, or soundboard, plays one of the biggest roles in an acoustic guitar's voice.' A spruce top with a large soundhole will sound different from a mahogany top with the same opening. The strings also matter: different materials and gauges change brightness and volume, and the soundhole transmits all of that.

If you are adding electronics later, remember that many acoustic-electric guitars use undersaddle pickups or soundhole pickups. A larger soundhole gives more room for a soundhole pickup, but it also may make feedback more likely in loud settings. The guitar's natural voice and the pickup system must work together. For models with built-in electronics, see our best acoustic-electric guitars.

Before you buy, spend time with each candidate guitar unplugged. Play it fingerstyle and with a flatpick, at low and high volume. That will tell you more about how the soundhole and the rest of the top respond than any spec sheet could.

What to pick for your use

Questions

Does a bigger soundhole always make a guitar louder?

Not always. Loudness depends on the entire top and body system. A larger soundhole can increase volume when paired with a body that can move enough air, but it can also reduce efficiency if the top is too flexible. The overall design matters more than the hole alone.

Can I change the soundhole diameter on my existing guitar?

No. Modifying the soundhole size is a structural alteration that requires professional luthier work and can seriously damage the top. If you want a different sound, consider a different guitar model rather than modifying the one you own.

Do classical guitars have a different soundhole diameter than steel-string guitars?

Classical guitars often have a slightly smaller soundhole relative to their body because the nylon strings produce less energy and the top is built differently. The result is a softer, warmer sound with less projection than many steel-string acoustics. For more on classical vs. steel-string, see our comparison.

How does the soundhole affect feedback in an acoustic-electric guitar?

A larger soundhole lets more sound escape, which can increase the chance of feedback when the guitar is amplified. Smaller soundholes are often less prone to feedback because they trap more sound inside. Some acoustic-electric models use a smaller hole or a feedback-reducing design.

Do soundhole pickups depend on the diameter?

Yes. Soundhole pickups are designed to fit inside the opening, so a larger diameter can accommodate larger pickups. If you plan to install a soundhole pickup, you need to match its size to your guitar's soundhole, which is another reason to consider the diameter when buying.