One of the major advantages of recording in the digital realm over the analog realm is the fact that signal processing is done by software, much of which is included within your DAW, rather than with expensive outboard gear. Digital signal processing, or DSP, is cheaper, easier to use, and has continued to become more accurate, more sophisticated and more innovative. In fact, DSP is so easy to use, and there are so many different types of third party processors available for your DAW, that instead of barely being able to scrape together the basics a big danger for the producer is using too much signal processing.

Today we will be talking about some simple but important knowledge regarding the classifications of the effects that processors apply to the signal. These effects are the same in both the digital and analog realms, because these effects relate to the basic building blocks of sound and are not exclusive to either domain.

Effects can be divided into three major categories that are applied to the three major physical characteristics of sound. First there are the dynamic effects. Dynamic effects control amplitude, which is the strength of the compression and rarification of sound waves as they move through the air. To the listener these effects affect the volume of the sound. Dynamic effects include compressors, limiters, expanders, and noise gates. We will talk about each of these effects and their applications later in the course.

Second, we have delay effects, which control the quality of the propagation of sound waves. Propagation is the measure of sound waves as they move through time and space. To the listener delay effects make certain parts of sounds appear to be three dimensional or happen at a different time than the rest of the sound. Delay effects include, reverbs, delays, phasers, flangers, and choruses. Once again, we will examine these effects individually later .

Finally we have Filter effects, which control the timbre. This is the measure of the relative balance between the amplitude and frequencies of a sound. This balancing produces the quality we often call tone in the ear of the listener. Filters are able to amplify or attenuate particular frequencies to produce the vast variety of tones we distinguish in our minds, apart from pitch or volume, that influence how we perceive sound. Filter effects include, high pass filters, low pass filters, band filters, parametric equalization and Graphic equalization.

Each of these effects are major tools available to the producer to shape and fine tune the quality of the sounds that comprise the final mix. Knowing which effects relate to which qualities of sound can tell us what effects processors to use when, where to place them in the signal path, and which tracks to group together to apply a particular effect to all of them at once. The application of each individual effect is an important piece of knowledge for the producer.