While EQ (equalization) is typically the first knob techs grab to dial-in a signal, a better move may be to start with attentive hearing and then follow by adjusting dynamics control parameters. After proper mic placement, correct gain staging, and appropriate high-pass filter engagement, it is beneficial to just listen to the channel in question before turning any knobs. If the channel sits well in the mix and has no tonal vices, let it be. If it needs some help in the low-mids, reduce those and listen again. The next step is usually to “box it in” through compression, limiting, gating and downward expansion. Let’s look at some ways these tools can help define a sound and deliver a better mix.
- Use gates only where they make sense. Digital consoles typically have a gate available on every channel, but in most instances only a few need a gate’s services. The most common application for a gate is rack and floor toms on a trap kit, and tympani mics in an orchestra. A gate essentially operates as an open-and-shut device for a signal with the set threshold serving as the voltage point between when a gate is open or closed. The mic is either on or off, with the only thing in between considered undesirable “chatter”. Gates on vocals are distracting unless there is a reason for creating that particular sound.
- Downward expanders are more useful than gates for most needs. Think of a downward expander as a gate with loose hinges. It can swing partially open or closed. Instead of yes or no, it is all the maybe in between. Expanders are great on B3 mics since they can keep out most of the rotary motor noises but still allow soft musical passages to come through. They are also perfect for a choir loft where ambient noise from HVAC is an issue.
- Compression is the primary tool to use on vocals. Every compressor has four parameters to adjust: Threshold (when), Ratio (how much), Attack (the grab) and Release (the let-go). On a digital console, it is important to prevent the signal from exceeding Full Scale level (0). Analog distorts nicely; digital does not. To that end, for typical worship vocals, set the Threshold so the compression begins several dB below 0, say around -10. Then set the ratio at 3:1 for gentle voices and 5:1 for strong voices. The attack can be set around 50ms, and the release about half a second. These are general settings, so adjust to suit the need. There may also be a Make-Up Gain on the backside. It can be left off except in cases where the compressed signal gets lost in the mix; but be aware: it is gain and it will bite.
- Use limiting only when the signal is absolutely uncontrollable – i.e., all youth room channels! Limiting is a brick-wall signal stop to prevent damage to equipment and ears.
- Be aware of how dynamics control alters the original sound. It is at the heart of all modern drum sounds. It is common practice to parallel process drums with compression and then merge the two variants back together into a massive sounding rig. While not natural, it is the sound people now expect. Phil Collins came up with gated reverb in the ‘80s and it is now enjoying a renaissance. So, put “In the Air Tonight” on and listen to how it was done originally. Compression has a dark side, too. Since (with certain settings) it turns down loud passages and turns up soft passages, applying it to wedge monitors can be dangerous. As the vocalist gets soft, the compressor raises the level and feedback can occur. During soundcheck, over-compress until the feedback happens and then dial it back down to a safe level and note the point of no return (Kansas used compression well).