Timbre model of software musical instrument based on sine interpolation

This paper presents a model to adjust timbre of software musical instrument by changing timbre parameters. The model is based on sine interpolation. It includes two sub models, vibration and amplitude envelope. To reflect the frequency spectrum, the model provides several parameters: offset coefficient, amplitude coefficient and frequency coefficient. The corresponding frequency spectrum of each parameter combination is obtained using DCT in VC++ environment. The relationship between parameters and timbres is found, by analyzing how parameters affect frequency spectrums. The results show that increasing offset coefficient and amplitude coefficient or reducing frequency coefficient can enhance the high frequency sections; thus instrument timbre is bright while contrarily timbre is faint. Compared with the technology of hardware-oriented timbre composition, this software method is flexible, revisable, and its cost is low.