What is Gain Staging and Headroom?
Gain Staging and Headroom are often two concepts that are commonly mistaken for one another. Being extremely important to the recording process, understanding the difference between gain staging and headroom will not only lead you to better quality recordings but advance your knowledge of the recording process in the right direction.
What is Gain Staging:
The amount of signal sent to your DAW provided by your preamp
Gain staging simply put is the amount of signal you give your sound source before it is sent to your DAW or multitrack recorder. Think of it like this. Your microphone on its own needs gain to record a signal into to it. This often comes in the form of the gain knob. Gain is the amount of signal you want to capture from a sound source.
Finding a healthy level of gain per instrument when recording is part of becoming a veteran recording engineer. Too much gain will result in oversaturation and peaking while to little gain will result in a degradation of sound with a very high signal to noise ratio. Pushing too much gain into your DAW will lead to little headroom to work with.
Do not get gain confused with volume. Volume is simply how much of the signal you want to be heard, not what is being transmitted into the mic by the preamp. Many inexperienced sound engineers will get these two confused when they first start out. They may notice that the audio signal is to low and boost the volume when in reality they needed to boost the gain to get more of a signal sent to the channel.
What is Headroom?
The amount of decibels left to work with in your meter before clipping occurs
When working in a DAW, headroom is basically the space that is left after the gain staging has been made. If you look at a digital channel meter it is the space left above the highest peak of the signal. Why is this important? That space above the meter is called headroom. This headroom is the amount of space you have to work with when you start adding effects and plugins to the signal chain. Most plugins, especially compressors, will add their own internal gain boosting the signal more than a few decibels. If you did not leave enough headroom within the channel you then begin to experience clipping.
Clipping is that nasty, distortion filled sound we get when there is too much signal within the channel being created. Remember that in the digital world, clipping begins at 0 dbfs. It is very easy to reach this level when you have oversupplied your DAW with the signal from the preamp. It gets even worse when you begin to add plugins that further amplify your sound.
Healthy Amount of signal
Remember that there really is no reason to be sending oversaturated signals to your DAW anymore. Back in the analogue days where everyone recorded to tape this may have been the case, but those days are honestly over. Most music production is done on computers. You don’t need be pushing your meter so high when you are gain staging your microphones. The signal to noise ratio is just really not there anymore. If your signal sounds clean and clear with a healthy amount of gain, use it. This will not only lead to better recordings but will leave you with enough headroom to work with within your DAW.
You should always be trying to avoid the red peak levels in your DAW. Digital Audio Workstation don’t work like large analogue multitrack consoles. Overloading your signal will not result in harmonic coloration like the old days. In the digital world always try to be precise when it comes to your levels within your DAW and watch out for clipping.