Digital Dynamic Range Compressor Design— A Tutorial and Analysis

Dynamic range compression, despite being one of the most widely used audio effects, is still poorly understood, and there is little formal knowledge and analysis of compressor design techniques. In this tutorial we describe several different approaches to digital dynamic range compressor design. Digital implementations of several classic analog approaches are given, as well as designs from recent literature, and new approaches that address possible issues. Several design techniques are analyzed and compared, including RMS and peak–based approaches, feedforward and feedback designs, and linear and log domain level detection. We explain what makes the designs sound different and provide metrics to analyze their quality. Finally, we provide recommendations for high performance compressor design.