I mix FOH at my family’s church, and I love it. In the past few years that we’ve been in our new sanctuary, I’ve enjoyed having subs at my disposal. We have a rotation of several FOH mixers, so we’re only pressed into service every few Sundays, and sometimes a month will pass between services I mix. As recently as a few months ago, we mixers have been tapped on the shoulder and asked, “could you back off on the subs a bit?” And I’ve always been happy to oblige the wishes of the folks who make such decisions. And I prefer to have more power than necessary and pull it down to tasteful levels.
But then came the evening when a well-known worship group played in our sanctuary.
This group had a LOT of low-end. And they cranked up to substantially higher SPLs than we normally do, because — you know — it was a big, special evening of worship. Ever since then, we’ve been asked to kick the subs UP a notch on Sunday mornings. Okay, cool! It’s almost as if a major act bringing in their big bass granted us permission to push it a bit louder than we had before. And we are happy about it. Obviously, there is such a thing as Too Much Bass, and we definitely don’t want to venture into that territory. But at the end of the day, it is just nice to have enough bass.
Bump the Thump
Why should we even consider the use of subs in our sanctuaries? I have identified four reasons to consider that possibility. First, people are now accustomed to hearing (and feeling) a lot more low-end than ever before — the result of attending pop and rock concerts, not to mention the massive LF content of today’s blockbuster Hollywood movies. And deep low-end isn’t confined to movie theaters — many homes also feature large, powerful subwoofers in the home theater environment. Second, modern worship music tends to feature more low-end than ever. Worship tracks may feature synth pads with substantial bass, and electric bassists may choose to use five- and six-string basses, which push the lowest note down from around 40 Hz to about 30 Hz. And my church has actually deployed a dedicated bass synth, played by our regular bassists. I’m pretty sure those get even lower than what a five or six-string bass guitar can do.
A third reason to consider the deployment of subwoofers is that rap, hip-hop and EDM have arrived in church. These genres are heavily represented in services for the younger set, and they rely extensively on low-end. A fourth reason to consider adding subs is that old audio principle: we get better fidelity when we divide the audio spectrum over more bands, and — if it’s done properly — adding an additional low-frequency band will make everything sound better. In fact, as congregations expect more low-end, less experienced engineers might try to coax that deep bass from a system that’s not capable of it, which can cause distortion and other problems. If we add the capacity for deep low-end, we don’t have to try to force more bass than the system can handle.
So how do we go about getting subs into our sanctuary? Well — the optimal way is to start from scratch and deploy a brand new system that’s custom-designed from the outset to include subwoofers. Hopefully it’s obvious why it’s preferable to design and deploy the entire system in one fell swoop. Making additional subwoofers work with an existing system in an existing acoustical space will be more challenging than designing a full-range system from the ground up. One obvious drawback to installing a new system is the comparative cost. If the budget allows, it’s better to do so, but in many cases, the budget simply will not allow.
Measure Up!
Whether a completely new system is going in or we’re adding subs to the existing rig, measurement is absolutely critical. We can’t just guess at the acoustical attributes of our space, nor can we guess at the quantity of speakers or amplification power we’ll need. If we’re adding subs to an existing system, we need to ensure they’ll provide at least as much low-end as necessary to match the output of our existing system. It’s OK for it to be a bit overpowered — we can always turn it down — but if it’s underpowered, there’s not much point in doing it to begin with. Bottom line, extensive measurement throughout the process is necessary to make sure it’s going to work as expected. And if it’s supported by the budget, we’ll almost certainly want to call in professionals to oversee and execute these measurements and system deployments. DIY is plausible too, but do your homework and get it right.
Bass Routing
Also, think about bass management. We essentially have two options: let our P.A.’s signal processing system to automatically handle the low-end, or we route all the LF to an aux at the mixer, and allow our FOH engineer to “salt to taste” by tweaking the level of bass. One big advantage of the former modality is that it’s friendly to volunteer mixers — one less thing for them to have to think about. Another positive here is that young volunteers may be too enthusiastic with the low-end. There are benefits to putting the low-end on an aux; one that springs to mind is the capacity for the FOH mixer to adjust low-end to a level that’s appropriate for the moment. At my church, we have such an arrangement, and it resulted from a desire to reduce low-end during our post-sermon response, when parishioners approach the platform for prayer. Our four 15” subs are in caves under the platform, and this placement created a bit of an issue. Before we routed low-end to an aux, we got complaints that the heavy bass made it difficult for parishioners to converse and pray together during the response segment of the service. Now, we just pull the LF fader down 5-10 dB during that segment, and folks can communicate clearly.
Another consideration is the sanctuary’s acoustical isolation. We know low-frequency waves are physically long — tending to penetrate through walls, and it takes a lot of work to corral them and keep them where we want them. Our church discontinued mixing a live stream (we now record, mix and publish a couple of days later). For a while, I was tapped to mix the Sunday live streams, which thrilled me to no end. One thing I did not like was the “isolated” room where I mixed the stream was isolated above around 250 Hz, but below that, the low-end from the sanctuary passed through a couple of rooms and permeated my mix environment. After the fact, listening back to my initial online mixes, I discovered they were bass-light. I realized this was because my mixing environment presented me with both the output of my monitor sub and also the LF coming directly from the sanctuary. In a perfect world, I would have only heard the output of the monitor sub, but as I was also hearing bass through the walls, I tended to pull the bass down in my mix, making my streaming mix a bit imbalanced — not enough bass. One solution would be to move the live stream mix suite to another building to sufficiently isolate it, but this isn’t practical or even possible for a lot of churches. I wouldn’t be surprised to see the mix of the stream relocated to remote locations away from the church building in the years to come. We’re already seeing solutions to facilitate this even right now.
Having the capacity for additional low-end will improve your church’s overall worship experience. It’s worth spending some time, effort and resources to design and deploy a system yielding the additional low-end our parishioners have come to expect.
John McJunkin is the chief engineer and staff producer in the studio at Grand Canyon University.
