In this article we’ll discuss gain staging and why its important for every musician to know. When I play music and the sound isn’t up to my standards, it bothers me. It bugs me during practice, even more during a gig, and is unacceptable when recording. Likewise, I can’t stand it when I go to a concert or wedding, and the band or DJ sounds terrible. I’m not talking about the choice of music or style of mixing (that is for another article). I mean the music sounds distorted, lacks balance, breaks up, or has lots of hiss and noise.
What is Headroom?
More often than not this is from the DJ, band, or engineer’s lack of knowledge regarding system gain (gain staging). You must set every step of the audio signal chain properly to achieve optimum sound and headroom. Headroom is a term referring to the system’s ability to handle loud program peaks. Distortion occurs when your mix isn’t set properly, resulting in distortion and physical pain in the ears of the audience.
Setting gain structure means properly adjusting each of your devices so that the audio signal is strong throughout the chain. If you hear noise, hiss, or distortion in the speakers, chances are something in your signal path is not setup correctly.
Know the Flow
In a traditional live setup, audio flows from the instrument (or microphone) to the preamp (or preamp inside the mixer) to the mixing console (which has individual channel faders and a master fader), processing equipment, and then the amplifier (or powered speakers which have built-in amplifiers).
Each piece in the chain should be set to Unity Gain, or 0 dB when the input sources are delivering a strong signal. If you look at a mixer, you’ll see a “0” (zero) mark on each channel as well as on the mixer’s output level. Unity, in the context of gain structure, refers to whatever is goes in is the same going out. Unity Gain is the goal of having the same signal entering the device and leaving the device.
This allows for peaks in the signal that may exceed zero to pass through undistorted. When the system or device in the chain can no longer provide an increase in output corresponding to an increase in input, clipping occurs.
How to do it?
Whether you are playing an instrument or DJing, start by making sure your volume is turned up. The instrument should be set to at least 75% of the available volume. This will ensure a strong signal as well as give the musician a bit of room should they need a bit more. Look at the mixer channel’s input meter. You’ll want to make sure your signal is triggering the yellow lights but avoiding the red. Adjust the gain on the mixer until you have the healthy signal. Once your signal is strong, you can lower the volume of the instrument using the channel fader.
If you are a DJ, your DJ mixer is the instrument. Make sure each channel (whether turntables, cd players, or digital channels from DJ software) has a strong signal. Then make sure your DJ mixer’s master outputs are pumping but not clipping. This means the signal can nudge a bit of the red from time to time.
Use this same approach for each step in the chain. If the signals are going through an effects processor, again, carefully look at the input and the output meters. Do the same for the amplifier or speakers. If you follow this approach, you should limit the noise and hiss as well as avoid distortion and clipping.
The Sum is the Means
- Proper gain staging allows for the following:
- Improved signal-to-noise ratio (increasing signal while decreasing noise)
- Elimination of most noticeable hiss
- Avoidance of distortion and clipping
- Improved dynamic range (more headroom)
- Better overall sound quality
Always set up each piece of gear in the order of the signal chain. Remember that if not enough signal is going into the amplification stage, you’ll be amplifying a lot of noise along with your weak audio signal. Gain staging is a way of life and will soon be part of your system setup.
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