How do you learn to mix? In my experience, it’s difficult without some one-on-one instruction and a lot of hands on. It can be a bit like learning to ride a bike, so make sure you’re wearing your protective gear and expect to take a tumble now and again.
In the spirit of adventure and maybe with a couple cuts and bruises, here are the key techniques that can have an immediate impact on your mixes. Some of this may seem obvious, but trust me, most mistakes stem from ignoring these fundamental steps.
Note: Before the kick drum and guitar are going to sound good, the PA system needs to be tonally balanced for the venue. If not, none of what follows here will produce the desired result. In fact, a poorly tuned PA can actually impede the mixing process considerably.
I concede that mix engineers don’t always have access to the tools needed to put a system back into balance if it wasn’t set up well in the first place, but if you’re able to make adjustments, or suggest positive helpful fixes to the technical staff at the church, please do so. That said, let’s move along to the actual mix.
1) Lay the groundwork with solid gain structure. Achieving an optimal gain structure from inputs to outputs within the console is extremely important. It’s a fundamental technique, but if overlooked can eventually lead to unsavory results. Most mix engineers differ on this issue. There isn’t an absolute right and wrong, so find a signal flow process that works best for you while keeping best practices in mind. Here are some tips to achieve good gain structure.
• Select a channel and set its preamp for a nominal meter reading with medium intensity input – let’s say 0 dB (analog) or -18 dB or so (digital). (See the sidebar for more about console metering levels.) Leave some room for peaks of +6 dB or so from the nominal level, and also be sure really quiet stuff doesn’t read too low on the meter.
• Slowly bring up the channel’s fader to the 0 dB mark. If the PA system is way too loud or quiet with a good preamp gain setting and the fader at zero, there’s some work to do on the output side. If the system is a little too loud at this point, bring the left/right master fader down slightly (-5 or -6) and carry on.
• Rinse and repeat this process for each individual channel. Ensuring the preamp gain isn’t too hot and the faders are comfortable at the 0 dB mark should lead to a relatively good balance on the inputs. As the inputs combine, you may need to bring the master fader down from 0 to -5/-6 dB because all the inputs are summing together and adding level at the master.
2) Use high-pass filters (HPF) to clean things up and then EQ to create space. This is an extremely important technique. Engage the input channel HPF to remove unwanted low-frequency (LF) content from the instruments. Remember, if the PA is tonally balanced (without a lot of LF build up), there shouldn’t be the need to roll up the HPF frequencies as high. Vocal mics may only be high-passed at 80 or 100 Hz as opposed to 200 to 250 Hz.
The point is that carefully applying HPF to input channels helps clean up the overall low-frequency and low-mid-frequency build-up in the mix in addition to providing the space to hear each instrument with more clarity and definition.