The best tone is acheived with a solid, non-veneered soundboard made from the finest coniferous woods such as cedar and spruce.
Engelmann Spruce - Rocky Mountains of British Columbia. This spruce is a popular soundboard wood for North American stringed instrument makers, and has a tone similar to high-altitude European Alpine White Spruce. It has a light, creamy colour, and is harder and stiffer than cedar.
The tone it produces is round, open & full with a good, clear treble and is more or less evenly balanced between the treble and bass. Spruce can sometimes take up to a year to develop it full tone.
Port Orford White Cedar - Coastal Oregon, USA. This variety of cedar is white in colour and almost looks like spruce. This species of cedar is not well known outside the Pacific Northwest, but I think that it deserves increased use.
Cedar is known for its increased volume, warmth, wealth of harmonics (overtones) and 'bass-iness'. What is most characteristic of cedar is that it takes only a short time for the voice to mature, and can even sound 'played-in' when new.