It’s also compatible with virtually every DAW. It’s a truly deep, accurate and useful metering plugin, which is refreshing considering that it’s free. The interface is simple, clear, and even somewhat customizable. It provides spectral analysis, correlation metering and clipping detection, as well as displaying RMS and max crest factor. Voxengo SPANĪs I cover in the course, Metering is absolutely essential to mastering, and SPAN is a versatile and free utility plugin. Here are some completely free plugins that you can work into your in the box mastering workflow … 1. Although nothing can replace an experienced engineer, working in an expertly designed room, on high-end equipment, there are some fantastic free tools available online that will aid engineers working on projects with limited budgets. As I cover in my new course Mastering in the Box, there are some incredible plugins available for anyone interested in computer-based mastering.