One might wonder, is there a difference between mixing audio for a secular live event, to mixing for a worship service?
As sound technicians and engineers, we have a responsibility to use our experience and the tools within the sound system at our disposal.
The audio components are the same, as are the basic fundamentals of mixing any live event: signal flow, equalization, dynamic processing, gain structure.
Many houses of worship today are equipped with the same sound system components that one would find are required as part of any given professional artist’s technical rider.
Nonetheless, it is important that the live sound engineer in the worship setting employs the same best practices as professional touring sound engineers.
For this piece, when speaking about dynamic control (equalizers and compressors), it should be understood that those components are typically a built-in feature of a digital console, while when using an analog console, outboard gear is required. However, you can also interface outboard gear to a digital console.
Tip #1: The objective of any successful live mix should be speech intelligibility and musical clarity.
In a worship environment, the audience is in place to hear what the pastor, minister, or speaker is saying.
As sound technicians and engineers, we have a responsibility to use our experience and the tools within the sound system at our disposal, to ensure that the congregants clearly understand the spoken word.
All sound systems should have at least one equalizer in the signal flow, between the microphone and the loudspeakers. There should be an equalizer on the channel strip of any reputable mixing console, but additionally, the mixing console should have an equalizer inserted on the main bus.
While the main bus equalizer serves to control total balance of the entire sound system, the equalizer of the channel strip, which is usually a parametric equalizer, is used to fine tune the tone of the voice (or musical instrument) being mixed.
Since every voice has its own unique characteristics relating to tone and strength, the audio engineer has the task of controlling those characteristics for each person that speaks into a microphone.
The importance of understanding equalization and how to apply it, cannot be overstated. This applies to equalization of instruments and vocals. Moreover, to properly apply equalization, a sound engineer must have a firm grasp of the musical audio frequency spectrum, and the frequency range produced by each individual instrument, including the human vocal chords.
Tip #2: The human voice has an intelligibility range between 900 Hz and 8 kHz.
Slightly boosting frequencies between 3 kHz and 6 kHz will give you more clarity. To remove some of the nasal tones, try decreasing frequencies between 800 Hz and 1 kHz. You will notice there is some overlap in the frequencies mentioned above.
Tweak and fine tune your equalization to the voice of the person behind the microphone, understanding that male and female voices differ in their vocal qualities and characteristics.
EQing vocals often require a surgical approach.
Sound engineers mix with the goal of delivering music with the punch and clarity that the musicians intend to deliver from stage, balanced with vocals. Mixing vocals with worship music is a delicate balance because, while you want the music to be impactful and have clarity, it is important that the vocals are adequately heard, to deliver the message of the lyrics.
Understanding how to apply equalization to vocals to achieve speech intelligibility, couples with understanding the frequency spectrum of musical instruments typically used in worship music. For example, EQing bass and the kick drum correctly is the foundation of achieving a good overall musical mix.
Tip #3: If you’ve decided to emphasize the kick drum at 80 Hz, you should be careful to avoid pushing the bass at the same frequency.
Try emphasizing 40 Hz and 120 Hz. That’s a good starting point, but that might also change, as you introduce other instruments into the mix.
BUSSING: Sub Groups, VCAs and DCAs
Voltage Controlled Amplifiers, or VCAs, and Digitally Controlled Amplifiers, or DCAs, each when using groups, can control multiple channels, as if they are one.
Sub Groups (or simply, Groups)
If your mixing console is equipped with a group section, it’s probably a good idea to make good use of it. Using the group bus section of the audio console is one way of streamlining your mix workflow. As an example, while you will always have control over each individual drum in the drum kit, it’s good practice to combine all the drums in a group. The same can be done for all your keyboards, if you have a main keyboard player and an auxiliary keyboard player.
Tip #4: If you have a group to spare, try grouping the overhead cymbals in the ride cymbal. This gives you additional control, if and when the cymbals become overbearing in the overall mix, but you want to keep the drum mix constant.
The practice of using groups for your instruments and vocals, also allows you to add additional dynamic control, such as compression, to the group bus.
Tip #5: Try grouping background vocals. Although you can compress every individual background vocalist channel, you can also compress the vocal group to keep the background vocals under control.
Additionally, try compressing the backing vocals at a ratio of 3:1, until you get anywhere between 5 to 10 dB of gain reduction. That might seem like hard compression, and it is to a degree, but you can also make it up on the make-up gain stage of the compressor. This practice helps to keep any stray voices under control and helps balance the background vocal mix.
It’s important to note that when raising or lowering the group, the volume levels of the signal being sent to other locations, such as a post fader mix, like a reverb unit, stays the same. So, if you lower the vocal group fader, you will still hear those channels through your reverb unit.
VCAs and DCAs
Using the example above, the benefit of the VCA/DCA group is that when you lower the volume on the VCA channel, it’s lowering the output of each channel. Therefore, any post fader mixes, like the reverb units mentioned, are equally affected.
VCAs are found on analog mixing consoles, and work by attenuating or increasing the audio signal going back to the channel(s) being controlled, increasing or decreasing the volume out of that individual channel.
DCAs (found on digital mixing consoles) do the same thing, except instead of using voltage to alter the signal, the signal is digitally processed to achieve the same result.
The Mix Approach
Tip #6: Remember to employ the “less is more” approach.
Professional sound engineers understand how to employ the less is more approach to a musical mix. This approach is best explained when an element of a mix isn’t quite cutting through to your satisfaction, as the sound engineer. The easy remedy would appear to be to simply push the fader, increase the gain stage on the compressor or use the equalizer to increase the frequency or the volume of whichever instrument or vocal is lacking within the mix.
Conversely, applying the less is more approach requires that you also find something within the mix that you can afford to decrease the level. For example, if you need more guitar in the mix, is it possible that pulling the volume (fader) down on any other given instrument would afford space for the guitar?
More often than not, you may find that the vocals are the culprit in a mix that seems to have ‘gotten away from you.’ I would encourage you to try pulling the vocals back into the mix a bit, before attempting to increase the volume on any given element of your mix.
Tools of the Trade
Tip #7: Part of the arsenal of a sound engineer should be a measurement mic and sound system acoustic analysis and measurement analyzing software, such as Rational Acoustics' SMAART.
The best mixing techniques can only take you so far, if the sound system you’re mixing on isn’t properly time aligned (between the mains, subs and front fills, for example) as well as equalized.
Knowing how to identify (by ear and in real-time) harsh and offending frequencies while mixing, will help you to pull those frequencies under control, but using your measurement microphone connected to SMAART is a powerful visual aid to contour the sound system to the worship space.
Once the house of worship is ‘dialed in,’ I would encourage worship facilities’ technical directors and audio directors to intently focus on the loudness levels that make up the audio mix.
To that end, another tool of the trade that I’ve recently found useful in keeping my mix under control, as it relates to sound pressure levels (SPLs), is TREND software. There are OSHA standards that all live mix engineers should be aware of, to remain in compliance. TREND helps keep us in line with those standards.
The TREND kit comes with a calibrated microphone/meter that accurately measures SPLs. As an accountability tool, TREND has a feature that logs and emails a report to whomever you designate within the software, when the SPLs reach 100 db.
My hope is that you all enjoy a robust balanced mix, while keeping it safely under control, and that some of the tips detailed in this article prove useful.