Different woods for different sounds
There are some predictable characteristics in the combination of various woods used in the making of an ukulele, listed below. Do note that every instrument sounds slightly different, even when they are made of the same woods.
Mahogany top, back, and sides (all Mahogany): A traditional combination used for many years by famous makers such C.F. Martin Company for guitars and ukuleles. The sound is sweet, and mellow. Bass tones are sufficient and trebles are somewhat soft and muted. In time, this combination ages to produce the classic sweet ukulele sound.
Koa top, back, and sides (all Koa): One of the most common and preferred wood choices throughout the history of ukulele building. Koa produces a predominately bright treble response with less volume than spruce, but the slight loss in volume is overshadowed by the extreme beauty of the grain.
Mahogany sides and back with Spruce top: Has all the characteristics of all Mahogany but with a wider tonal range and greater volume projection.
Mahogany sides and back with Cedar or Redwood top: Like the Mahogany/Spruce combination, but with a softer treble tone and slightly less projection.
Koa with Spruce, Cedar, or Redwood: Similar to the Mahogany/Cedar combination, but has a brighter treble response.
Kula Wood (Gold Shower, Prima Vera) with Spruce: Produces excellent tone and visually stunning.
Maple sides and back with Spruce top: Bright tone, strong projection, most Maple wood especially curly Flame Maple is visually beautiful.
Maple sides and back with Cedar or Redwood: Similar to Maple/Spruce but more warmth of tone, and less projection.
Rosewood sides and back with Spruce top: Traditional combination for volume and deep tone.
Rosewood sides and back with Cedar top: Enhanced depth and bass, Cedar produces a more "matured" tone.
Macassar Ebony back and sides with Spruce or Sequoia Ebony top: Using Spruce will create more projection and enhanced treble and bass clarity. However, Sequoia Redwood, with similar properties also produces a beautiful tone. The decision to either use Spruce or Redwood is also determined by visual preference, namely a creamy white top, or dark brown top, again, both are beautiful.
