Monitoring for Choirs

by Vince Lepore
in Sound Sanctuary
Fig. 1 - L-Acoustics X8 coaxial loudspeakers' predicted coverage. Yellow area is the main choir loft listening plane.
Fig. 1 - L-Acoustics X8 coaxial loudspeakers' predicted coverage. Yellow area is the main choir loft listening plane.

One of the most challenging aspects of our traditional worship and special events is monitoring for the choir. Below are some suggestions for getting the most out of your choir monitors. My church has been coasting along on an old and inadequate set of loudspeakers for the past decade and we make it work, so it’s not impossible by any means.

‡‡    Ensuring Proper Coverage
If you’ve read my articles, you know that I often discuss the importance of loudspeaker selection and aiming. It makes all the difference in the world. A great loudspeaker that is poorly aimed will perform poorly, but a great loudspeaker that is aimed for precise coverage and optimal gain before feedback will be much more successful, especially in a monitoring application.
In early 2018, we are upgrading our choir monitoring, and I’ve chosen a pair of L-Acoustics X8 coaxial enclosures to handle the task. Yet when choosing loudspeakers from any manufacturer, make use of their free design and prediction software (Meyer MAPP, L-Acoustics Soundvision, d&B ArrayCalc, etc) to find the ideal loudspeaker for your space. Fig. 1 shows the prediction of our choir loft covered by the pair of X8’s. We found that these provided the ideal balance of proper coverage, frequency response and maximum SPL that suited our needs and budget. Soundvision software helped us predict the ideal orientation, location, height and aiming for the loudspeakers to provide optimal coverage to the choir loft while minimizing spill onto the area in front, which is used for instrumentation.  

‡‡    Monitor Tuning
When I first joined the staff of my church over a decade ago, we had a lot of problems with our choir sound in the house and in the monitors. Someone had decided to hang shotgun mics over the choir. I’m sure they had the best of intentions, hoping to improve gain before feedback by using the tightest polar pattern available, but you can imagine how spotty the pickup of the choir was. We’ve made many incremental improvements over the years that will finally culminate with a completely new sound system in 2018.
One of the big improvements we made was re-tuning the monitor loudspeakers (using SMAART) to have much flatter frequency response. The tuning process took a few hours and cost us nothing other than the labor for myself and one of our audio techs. When I first started, the choir monitors really didn’t have a DSP available to them. Ultimately, when we upgraded from an analog to a digital console, we used parametric EQ plug-ins to tune the monitors and it provided a noticeable increase in stability and gain before feedback. The difference a well-tuned loudspeaker makes never ceases to amaze me.

‡‡    The Choir Mix
There are several mixing techniques we use to get the most out of our choir monitors. The first, and most obvious, is a timeless technique used by monitor engineers the world over, which is not responding to every single request to “turn things up!” Our choir often reaches between 80 and 90 people during the busiest times of year. If we responded to every single request for monitor changes, we’d be mixing choir monitors exclusively. We make some of our own judgments about whether requests to “turn things up” are practical, or if they are going to push us into feedback.
Many times, we find ourselves turning something else down rather than turning something up. For example, if the choir is asking for more of themselves, we’ll listen to the level of the piano and solo vocalists that are accompanying the choir. If the piano is too loud, we’ll turn it down and the choir will be happier with the level of their own mics. Other times the choir is fighting against the level of the pipe organ, which is situated directly behind the choir loft. This is a lose-lose situation for the audio team. We simply cannot compete with the pipe organ, so that’s a battle we don’t even attempt to fight.
A second helpful technique is to cross-pan choir microphones into the opposite monitor. I use this technique not just for monitors but also for FOH. For example, take the furthest stage left choir microphone, and pan it mostly into the furthest stage right monitor. This provides two benefits. First, it helps one side of the choir hear the other side of the choir, allowing the sopranos to better hear the altos, for example. This also improves gain before feedback, because that far stage left mic is now primarily being reinforced by the stage right monitor. This makes it less likely that the dreaded feedback loop is going to occur, just based on the physical difference between the mic and the speaker reinforcing it.  
Third, and this should be fundamental to anyone mixing audio for a choir, is to use the equalization tools available to you. The high-pass filter is such an important tool when mixing choir mics and monitors. Don’t neglect it. I usually run my high-pass filters around 125 Hz except for the mic on the bass section, which I’ll run down to 100 Hz. I’m also a huge fan of the low-pass filter if your console has them available on each input channel. Many consoles unfortunately don’t have low passes on every channel, but they might be available as a plug-in. Use these to your advantage to roll off some of the extreme HF energy above 10k Hz. It may not give you a huge increase in gain before feedback, but used in conjunction with the high-pass, some parametric EQs, the cross-panning technique and properly tuned monitors, you’ll be well on your way to making the choir and the audio team happy.
One final tip, because many people haven’t seen or used these before, is to try out a piano sensor rather than using microphones in the piano. Several companies such as Barcus Berry and Schertler make such products, but the most popular, and the one I’ve used, is from Helpinstill. This is a magnetic pickup that gets installed in the piano. Because it is a pickup and not a microphone, it is drastically less likely to feedback, and it only captures the piano and not any adjacent bleed. This means you can dial piano into your choir monitors without fear of it feeding back. I have experimented with using the Helpinstill sensor by itself and using it in conjunction with mics. I still prefer the microphones for the FOH mix, but a piano sensor can be a lifesaver if the piano needs to overcome a loud choir, pipe organ or other instrumentation nearby.
As with most things in audioworld, there really is no silver bullet that is going to solve all your choir monitoring problems. Careful application of these various techniques, coupled with experience in your own space, will ultimately keep your choir happy.   

Vince Lepore is the technical director at St. Luke’s United Methodist Church in Orlando and teaches live production at Full Sail University.