Acoustic guitars are mainly made of wood. Sounds from acoustic guitars made of different wood are also different. The wood determine the sound and price of an acoustic guitar. Some wood sound bright while others sound warm. The rarity of some types of wood will increase the cost of guitars made of them. Some cheap guitars are made of laminate not solid wood. Laminates are consider don’t have the sound characteristics of solid wood. Although some acoustic guitar featured all wood guitars, most guitar makers think the material of top contribute most to an acoustic guitar tone. For affordable beginner guitars, the combination of solid top with laminate back and side is a good option.
Spruce is a standard acoustic guitar top material. There are different kinds of spruce and Sitka is most commonly used. It is strong and light weighted. The guitars made of Sitka usually have good clarity and sustain even when played heavily.
Cedar is a kind of soft wood. It has good balanced warm sound and response quickly to light playing like finger-picking styles. Most nylon string classical guitars use cedar as top sometimes as back and side.
Mahogany is mostly used in for backs and sides. When used as top, mahogany makes sound focus on upper end of sound spectrum which is better for country blues music style.
The real tone of an acoustic guitar is also determined by design, the brands and other factors.