This 术语 提及 to any 混 or 信号 处理 技能 that aims to 增 the richness of a 声 频谱 content A 声波 may be transposed up or down or both and 混 with the 原始/原创 a 过程 which also 通常 包含 careful 均衡 If 多 versions of a 声波 in different 倍频程（八度） registers are 混 together the 术语 倍频程（八度） Stacking is sometimes used The addition of 特定 isolated areas of 频谱 to a mix can also be 描述 as 频谱 增厚 The 术语 could be thought of in a manner analagous to the 创作 in 技术 术语 rather than 语义 of 'composite sounds'