If you're new to the ukulele, and looking to upgrade from one of the bargain basement models, then all the combinations of attractive wood can be very tempting. Appearance alone should not be enough, however, since the woods chosen make a big contribution to how an ukulele sounds. Let's look at the most commonly available woods, and their effect on tone. In all stringed instruments, the wood the soundboard is made from has much more effect on the tone than any other part. This is because the vibration of the soundboard is what transmits most of the sound you hear into the air.
Unlike guitars, ukuleles tend to use the same wood for top, back and sides. This is because the most common ukulele topwoods, mahogany and koa, are both hardwoods, and whereas in guitar building, the common practise is to use softwoods like cedar and spruce for the top, and hardwoods for the back and sides, ukuleles, with their smaller soundboards, tend to get better results from hardwood tops. It's important to remember that unless the description of the ukulele specifically mentions solid wood, then it won't be; it'll be laminate, veneered with whatever the wood is being described as. When discussing tone, it's useful to understand the difference between the fundamental tone, or the specific note that's being played, and sympathetic harmonics, the other tones produced by the vibration of the wood which contribute to the tone. The more fundamental there is, the louder and simpler the instrument will sound, whereas the more harmonics there are, the more complex, warm and “blossoming” the sound will be.
Mahogany
Mahogany is the most common sold wood for ukulele construction, and perhaps the most traditional also. A mid brown in colour, with varying amounts of darker figuring, mahogany has a very dark tone, emphasising the mid and low tones, and without a particularly pronounced treble range. On small instruments like ukuleles, particularly sopranos, this results in a pronounced “bark” to the tone which is a key element of the traditional ukulele sound.
Koa
Koa is usually slightly lighter in colour than mahogany, and depending on the grade, varies from similar light figuring to mahogany through to very complex “curly” figuring on the most expensive pieces. It has a lighter, more delicate tone than mahogany, described by British ukulele luthier Pete Howlett as the “Island tone”, displaying a more pronounced, though not overbearing treble, and a slightly warmer and airier harmonics on the mid and lower tones. Koa is generally significantly more expensive than mahogany.
Spruce
Light in colour and generally without any figuring, spruce is the most common topwood for acoustic guitars. Its bright, ringing, trebly tone balances well with the larger size of the guitar, and its lower range. On an ukulele, however, some feel it to be too bright, loud and perhaps overbearing, particularly when combined with a rosewood back and sides. Spruce with a mahogany back and sides should be slightly softer and warmer in tone.
Cedar
A warmer, more orangey hue than spruce, cedar's tone is similarly warmer, with a less pronounced treble, and more blossoming sympathetic harmonics to the midtone. On steel string guitars, cedar can lose some of its tonal integrity when played very loudly, becoming muddy, but the combination of a smaller top and nylon strings on the ukulele tends to minimize this issue.
Laminates
Laminates are made from layers of wood glued together; essentially plywood, and are considerably cheaper than solid woods. They can look dramatically different dependent on the wood used for the final veneer, and since they all sound more or less the same, can be veneered with very dramatically figured woods, even if those woods are of dubious tonal quality when used as solids. Laminates display mostly the fundamental tone, with little in the way of sympathetic harmonics. This means that their tone is very simple, direct and loud, but could be characterised as boring.
Most low cost ukuleles will be made of laminate materials (and some surprisingly expensive ones, veneered in exotic woods), and laminate ukes can sound surprisingly good, compared to laminate guitars for instance. The small size of the ukulele's soundboard, and the generally direct and simple sound particularly of the smaller sizes means that the detrimental effect of the laminate is minimal. This is one of the things that makes the uke so accessible; very affordable instruments can still be pleasant enough to hear, and even very good ukulele players are often able to enjoy themselves playing inexpensive laminate instruments.
