The Science Behind Tonewoods: Unravelling the Secrets of Guitar Sound

Do you think, when it comes to the construction of guitars, that the choice of tonewood plays a role in shaping the instrument’s sound and character?

Can the same player, playing the same song with the same strings, but on guitars of two different woods, sound dramatically different?

The answer is an unequivocal YES!

In this article we’ll take a look at the tonewoods most commonly used in guitar making, We’ll explore their characteristics and find out how they contribute to the instrument’s sonic palette.

Hey, Jerry – What are Tonewoods?

I’m glad you asked. Tonewoods are the varieties of wood that have been found to produce the best, most musical sounds, based on their density, stiffness, and ability to resonate. It’s these factors that give the wood its unique tonal characteristic, and ultimately shape the guitar’s voice.

Let’s explore some popular tonewoods, their key characteristics, and the guitarists who love them.

Spruce

Spruce is THE most widely used tonewood for guitar tops. Its high stiffness-to-weight ratio (it’s very stiff but very light – a wonderful combination for guitars), coupled with its elasticity, contributes to its bright but not over-bright sound and impressive projection.

Spruce top guitars provide a balanced tonal response with a clear and defined articulation of individual notes.

Guitarist:

JERRY!

Mahogany

Mahogany is renowned for its warm, rich, and focused sound. I tend to think of it as ‘dark’.

It’s a relatively low density wood, making it suitable for back and sides although it’s becoming more common as a top as well. Mahogany tends to emphasise the midrange, offering a smooth and even response with a touch of warmth. It is favoured by players who need supreme definition and clarity in the midrange frequencies.

Guitarist:

Nick Drake, the tragic English singer-songwriter, was known for playing guitars with mahogany bodies. One of his most recognizable guitars was a Guild M20 guitar, which featured a mahogany body and a rosewood bridge and fingerboard.

While Nick played other guitars through his short career, his association with the mahogany-bodied Guild has become iconic due to its inclusion on the front cover of his Bryter Layter album.

Rosewood

Rosewood tends to feature pronounced overtones with a deep bass response, and complex harmonics. Although rosewood top guitars have been built, rosewood is rarely used as a top wood, because its lack of resonance makes it too quiet.  But it adds a subtle richness when used as a back and / or side wood. And it looks beautiful!

So while its dense and heavy nature doesn’t make it a good top wood, rosewood contributes to a full-bodied and rich tonal quality when mixed with something more resonant like spruce. Indeed, spruce and rosewood is perhaps the most iconic combination of tonewoods and we can find it in some of the worlds best acoustic guitars, like the Martin D28 and the Taylor 814.

Guitarist:

Neil Young’s Martin D28 is a legendary guitar for a legendary musician.

The guitar has become synonymous with Neil’s distinctive sound and playing style. He has used it extensively in his recordings and live performances, showcasing its ability to cut through the mix. The D28’s resonant rosewood back and sides contribute to the overall richness and complexity of the sound, making it a very special instrument for both Neil and his fans. And it has quite a history. It was owned by Hank Williams Sr!

Maple

Maple has a bright and clear sound, which gives guitars with maple tops a vibrant tonal character.

For some, (and I include myself), that brightness can be just a touch too much, but in the right hands it can be a sound of shimmering brilliance.

The tight grain and high density of maple contribute to its precise note articulation, making it an great choice for achieving definition and clarity. Maple bodies can add a distinct snap and tightness to the overall tone of an acoustic guitar.

Guitarist:

Check out Emmylou Harris playing her all maple J-200 for a perfect example of the crisp and bright tone of maple, and how great it can sound in the hands of someone born to play it.

Cedar

You might think of cedar as the opposite of maple.

Cedar is valued for its warm and responsive qualities. It’s often used as a top wood on acoustic guitars where it offers a more delicate and nuanced tonal response compared to spruce, with a greater emphasis on the midrange.

Cedar tops produce a rich, intimate sound with a quick attack and excellent dynamic range.

But a word of warning. It’s not for heavy strumming without a good pick guard. Cedar is a soft wood that will scratch quickly under heavy assault.

Guitarist:

Richard Thompson, one of the greatest guitarists of our time, plays a cedar-top Lowden guitar.

His signature model features a cedar top combined with East Indian rosewood back and sides. Although he tends to plug in for concerts, this guitar played acoustically sounds amazing, demonstrating the true richness of the cedar top.

Tonewood, of course, isn’t the only important factor in a guitar’s sound. Size, body shape, bracing and other factors all play a part.
But the choice of tonewood does affect several key aspects of a guitar’s sound.

Density and stiffness will influence the volume, sustain, and resonance, while the wood’s ability to absorb or reflect certain frequencies will contribute to tonal balance and projection.

And each wood has its own distinctive colour.

Try a few guitars built from different woods and see what you think.

And be sure to share your thoughts with us here.