Our ability to record sound is pretty phenomenal!
We take it for granted that we can tune in to the radio, listen to recorded music and hear recorded sound through phones, PCs, TVs and a whole host of other devices.
To streamline the process of recording sound for use across these devices, the recording studio was built.
The recording studio’s sole purpose is to optimize sound recording and make the whole process more flexible, more powerful and easier.
The Recording Studio
We all know that a studio is created from lots of interlinking audio devices.
These devices are linked through signals which travel along wires in what is known as the signal flow, or signal chain.
Understanding the signal chain will improve your overall knowledge of music production. It’s great to have a functional understanding of where signals go and why.
It will help you make decisions about your own setup and will improve the way you approach music production
…so, without further ado, let’s take an in-depth look at the signal chain!
From Source to Speakers
The sound is formed from physical vibrations which travel through a medium, like the air that surrounds us.
A modern studio’s task is essentially to convert these physical vibrations into a signal which can then be processed from within a computer. Once we’ve processed our signal in our DAW, we can do whatever else we need to do – make a CD, bounce to MP3, press to vinyl, etc.
You are converting physical sound energy into digital data which is then manipulated within a DAW before being converted again into sound energy for playback through speakers and headphones.
That, in short, is the signal chain.
…Back in the Day
Production hasn’t always been like this!
The digital age of audio started in the 1970s and since then, recording studios have developed to take full advantage of the flexibility that digital workstations and equipment have to offer.
Before, the recording studio was formed of analog gear, from microphones through to the tape recorder.
Every sound would be recorded continuously to magnetic recording tape. From there, it could then be transferred to other analog formats, like vinyl or cassette.
The Current Day…
Modern studios use either solely digital gear or a mixture of analog and digital gear.
Analog hardware effects like EQs and compressors are still used for their authentic sound quality but the digital versions of this analog gear, like Waves’ Abbey Road Collection, provide near-identical results from within your DAW.
Even in the biggest studio, the practical fundamentals of the signal flow are the same as in the smallest. The differences lie in the units used and how many there are. A pro level studio will use lots of different units which provide power, flexibility and other favorable audio traits and character.
So, let’s start off by taking a look at a highly complex pro-level signal flow:
Here, you can see that there is a different unit for practically everything! Wiring all of this up would take a fair while, and then there’s the cost ($250,000 +)!!
Most studios are not built like this, and instead, use fewer bits of kit. The following diagram shows a studio setup that may be more familiar to you:
In this setup, so many units displayed in the pro studio are seemingly replaced by just one: the audio interface.
Most modern audio interfaces, like the Focusrite Scarlett range, carry out the same tasks that lots of individual units do in complex studios.
A typical modern interface provides preamps and it also deals with our speaker and headphone outputs. Furthermore, the Analog to Digital or Digital to Analog Converter units shown in the first diagram are also built into the interface.
Modern interfaces pack all of those units into one bit of kit. Amazing!
Hardware FX is replaced by software plugins within our DAW, like the Abbey Road plugin mentioned earlier from manufacturer Waves.
The Fundamental Signal Flow
Now you’ve taken a look at how and why setups look different, you’ll best understand why their signal flow very similar underneath. The fundamental signal flow is the same in every recording studio.
Stage 1: Sound Source: Every recording studio’s signal flow begins at the sound source. Physical vibrations from an instrument, voice or other source are picked up by a microphone which converts sound energy into electrical energy. A microphone converts sound energy to electricity through a process known as transduction, much the same way as our ear converts physical vibrations into electricity that can be understood by brains.
As explained in this article about studio cabling, the electrical signal transmitted through a microphone wire is tiny – it’s way too weak to be detected by most audio gear.
This weak signal travels along a microphone wire and into an input on our interface.
Stage 2: Preamplification: In the interface, preamps amplify the tiny voltage from the microphone by around 1000 times to line level. Line level is the level accepted by most audio gear. It’s essentially a benchmark audio level for easy transmission between audio devices in the signal chain.
Stage 3: Analog to Digital Conversion: The next step is to take that electrical line level signal and convert it into a digital signal so a PC can understand it. This requires the use of an Analog to Digital Converter (A/D). As explained, any modern interface has one of these built-in but some pro-level studios will have a separate unit for this process.
Stage 4: Interface to PC: After our line-level signal has been converted into digital audio, it’s sent as data to our PC, usually through either USB, FireWire or Thunderbolt cables.
Result: Audio is in our DAW: At this stage, our signal has flowed from its origin as a physical sound to a pre-amp and then to an A/D converter which sends the resulting digital audio to our PC.
The next step of the signal flow is similar to the first but in reverse. Instead of getting physical sound into our PC from a microphone, we’re getting it out of our PC to speakers or headphones.
Stage 1: Digital to Analog Conversion: Our processed digital signal is sent from our DAW back along our USB, FireWire or Thunderbolt to our interface and this time, it’s turned back into an analog signal with a Digital to Analog Converter (D/A). Once again, this is built into most modern interfaces but pro-level studios may use a separate unit.
Stage 2: Interface to Speakers: This analog signal then finally flows to our speaker’s amplifiers, which may be either external units or inside the speakers themselves in the case of KRKs or similar. Alternatively, the signal may flow to a headphone amplifier.
Result: Sound! Finally, our mixed and processed sound flows out from our speakers as physical sound energy!
That’s the basic signal flow! Try and imagine the signal flowing around your setup. It’s pretty simple but once you get it, you can really see how audio systems link up into one working whole.