Musical instruments are mostly made of wood. Woods are chosen for their acoustic properties, durability, and aesthetic appeal. So what about carbon fiber? It has the same traits as wood but has better strength-to-weight ratios than anything natural can create.
As such, would musical instruments made out of carbon fiber be just as good or even replace wood in the future?
The answer is a resounding no, not anytime soon. Carbon fiber is great from an engineering perspective, but it lacks the tuning and resonance abilities needed for musical instruments, especially stringed ones.
Carbon Fiber vs. Wood: Strength-to-Weight Ratio
One of the main reasons carbon fiber is used for high-end bikes and cars is because its strength-to-weight ratio is off the charts. It’s about five times stronger than steel but half as heavy. It means a car made out of carbon fiber would be extremely light and fast while being strong enough to protect occupants from crashes.
Carbon fiber has the same strength-to-weight ratio in the longitudinal direction, allowing engineers to make very thin sheets that are still strong. However, if you take a piece of wood or metal and bend it to the same degree, it’ll likely snap. To compensate for this lack of flexibility, carbon fiber composites use many layers stacked on top of each other.
With carbon fibre string instruments, they would be extremely light and comfortable to hold or wear around. But the same flexibility issue is present, so the resonating properties of the soundboard would significantly suffer.
Carbon Fiber vs. Wood: Resonance Properties
Resonance properties are what make instruments sound good. An instrument’s body will vibrate just like any physical object if you strike it. When you strike a guitar, these vibrations will reach your ears and make your brain interpret the sound like music. The wood’s properties and the instrument’s shape affect these vibrations.
For example, some guitars have holes cut into them to reduce weight by cutting down on the material needed. However, this also reduces resonance because it’s harder for sound waves to bounce through a solid piece of wood than one with several open spaces throughout the body.
The most critical resonance factors for musical instruments are:
- The volume of the instrument’s air chamber (typically the hollowed-out body)
It is one of the most effective ways to change the sound quality. A larger chamber resonates longer than a small one and produces a lower pitch, while a smaller chamber resonates faster and produces a higher pitch.
- The body’s shape
It is discussed in the next section, but specific designs focus on maximizing resonance or minimizing it for a particular type of sound. For example, violin bodies have a perfect parabolic curve to amplify lower frequencies while minimizing high ones because violins primarily produce mid-tone sounds.
- The material the body is made from
Different types of wood have different densities and natural resonation properties, so a bass guitar will sound noticeably different if it has a solid mahogany top compared to a spruce top.
Carbon fiber and wood have similar strength-to-weight properties, but that’s about where the similarities end. As you just read, resonance makes instruments sound good, and carbon fiber cannot replicate those properties necessary to make them sound as good as they should.