The worst words for a sound tech to hear are, "we have a strict volume limit." These spoken words usually indicate a volume limit far below what most techs see as standard mixing volumes. The good news is volume limits can easily be met by building your mix in a different way. And it starts with the lead vocalist.
The standard method of mixing music is usually explained as making a multi-layered cake. The bottom layer, where you start, is the low-end instruments like the drums and the bass. Mix the next layer of electric guitars, going up layer-by-layer in frequency range and ending with the vocalist on top. This way, you've established a firm foundation and guarantee the vocals are out front. Using this method, you never really address a volume limit. When mixing with volume restrictions, you must invert the cake.
Inverting a cake isn't easy so let's put the cake aside and talk about a new form of mix layering.
1. Vocals First
The lead vocalist must be in the front of your mix. They are leading the congregation. It's the voice the congregation leans on to follow the melody, especially with a new song. That's why you should start this mix with the vocals (and a sound meter). Bring in the lead rhythm instrument to help the worship leader sing in time and on pitch. Don't push the vocal volume to hit the dB limit. Use a compression ratio of around 2.5:1 and leave yourself a few decibels of headroom. Bring in the backing vocalists at this point.
A tip on mixing lead vocals: Engage the HPF (high-pass filter) around the 200 Hz point for clearing up a tough vocal mix.
2. Bring on the Guitars
It's time to bring in the guitars. Bring in the rhythm guitar and follow it with the lead guitar. Work out the two instruments by carving out frequencies for each so they sound distinct while supporting the arrangement. In the case of the electric guitar, apply a HPF in the 400 Hz range so you are making room for the bass and drums. By carving out space ahead of time, you'll find the layering process easier.
It will sound rougher than your initial bottom-up mix. That's to be expected.
A tip on mixing acoustic guitars: Boost in the 1 kHz to 2 kHz to increase the guitar's presence.
3. Piano and Keyboards
It's hard to give a generic mix strategy because each song is different. For example, if the piano was the lead instrument in a particular song, I would have mixed the piano in before the guitars because it's the instrument that's directly supporting the singers.
A tip on keyboard mixing: cut what you don't need as the keys can take up a lot of un-necessary frequency space and muddy your mix.
4. The Bass
It's time to bring in the bass. You've got some low-end from your guitars and you're about to layer in the drums. Pull in the bass and EQ it so it gives a nice supportive vibe to the guitars but will stand out from the kick drum. Take comfort in the fact that mixing isn't finished the first time you set all of your channels.
A tip on bass mixing: Give the bass some solid attack by working in the 120 Hz to 4,200 Hz range.
5. Drums
At last, the drums! Start with the kick drum and mix your way up through the drum kit as normal.
A tip on drum mixing: Get the kick to cut through the mix by boosting in the 40 Hz to 80 Hz range or focusing on the beater head hitting the drumhead around the 2 kHz to 6 kHz range.
Mix Review and Adjustment
It's time to listen to your full mix. It will sound rougher than your initial bottom-up mix. That's to be expected. What's important is you've built a mix while keeping the vocals out front and respecting the volume constraints.
Keeping your vocal level set and an eye on your sound meter, re-adjust the volume levels of all your channels as necessary. Don't forget to have your compressors engaged. At this point, you have a good basic mix and you can spend your time working out the best EQ/effects settings.
I didn't mention percussion in the above layering because I like to use it for highlighting in my mix. If you have a percussion-heavy arrangement, layer them in after the bass.
You might wonder why you can't build a standard bottom-up mix and then lower the house fader. You could, but as frequencies are perceived at different volume levels, as soon as you lower the overall mix volume enough, your mix will fall apart.
In summary, working in a room with a strict volume limit that impacts the standard bottom-up mix building process, turn your focus to the lead singer and layer everything underneath.
