Signal flow is one of the most essential concepts to the success of the recording experience. Understanding and planning out the signal flow for a recording session will help in keeping a session stress-free and focused on the music. Yet if (and when) problems do arise between your source(s) and output (recording medium), a strong understanding of signal flow will help expedite the troubleshooting process, saving you and your musicians valuable time in a service-based industry where issues of money and creativity play a critical role in the outcome of the session.
Signal flow begins at the sound source, with a transduction stage. Transduction is the process of converting one type of energy into another form of energy. Within our diagram, the microphone(s) take the sound waves from the sound source and convert the sound waves into an electric current (through the process of transduction).
Once the audio signal is converted into an electric signal, the electric signal is sent to the console preamps. The preamps are used to change the impedance and amplify the signal to line level – the optimal operation level for most professional gear.
From the console preamps, the signal flows to the Analog to Digital Audio Interface (A/D), which converts the analog signal to a digital signal. In order for the DAW (Digital Audio Workstation) to read and process the information. Once we’ve processed the data within the DAW, we convert the signal back to analog (D/A), send it back to the console faders (not the preamps), and from there, the signal is sent to the power amps, which power the speakers.
A home studio deals with less complexity in comparison to a professional studio. A home studio generally has only a few microphones, no console, and a basic audio interface like a Mbox (for Pro Tools) or an Apogee Duet (for Logic). Although it’s simplified, all the processes that occur in a big studio still occur within the smaller interfaces that help power a smaller studio.
For instance, even though a small Mbox is not a console, it still contains a preamp, an A/D, a D/A, a power amp, and a headphone amp. So, even without the high-end gear of a professional studio, your signal flow still behaves predominantly in the same way in your home. Consequently, it is important to think of it and approach it in the same exact manner.