ABSTRACT
Audio sequencers let us mix inside-the-box. That is, they provide everything that is needed to complete a mix without external hardware (with the obvious exception of speakers). They can also be fully integrated with outboard gear and consoles when required. The software mixer provides the same core functionality as the mixing console: summing, processing and routing. For routing, each software mixer offers a generous number of internal buses, used mainly as group and auxiliary buses. In audio-sequencers jargon these are simply called buses. All audio sequencers ship with processors and effects, either integrated into the software mixer or in the form of plugins that can be loaded dynamically. Third-party plugins extend the selection and can offer additional features and quality. All of the processing is done in the digital domain, with calculation carried out on the host CPU. Both summing and routing are relatively lightweight tasks; processors and effects are the main consumers of processing power, and the CPU speed essentially determines how many plugins can be used simultaneously in the mix. DSP expansions – either internal cards or external units – offer their own plugins that use dedicated hardware processors instead of the computer CPU. Avid’s HD platform, Universal Audio’s UAD and Focusrite’s Liquid Mix are just a few examples.
