When I first began working in the world of worship, audio subwoofers were not very common in a typical church sound system. However, that was two decades ago. and a lot has changed in worship music. For that matter, a lot has changed in how we all listen to live music in general. The bottom line is that we have more bass frequencies in our music than ever before. Or, perhaps, we just have speakers that will reproduce bass more efficiently and pleasantly.
Personally, I like nicely tuned and well-controlled bass speakers. They add punch and more fullness to the low-end of just about any worship music. I don’t want to get into a physics lesson here, but keep in mind that those nice punchy low tones will require more energy (watts) to reproduce than higher treble frequencies. This fact is why we have speakers that are solely dedicated to reproducing bass frequencies. These speakers are called subwoofers or subs or bass bins or bass boxes, etc.
The Right Speaker for the Job
Subs can come in a variety of cabinet sizes and designs, but the raw speakers themselves are almost always 12-inch, 15-inch or 18-inch. Anything smaller than 12 inches just won’t do the job for your congregation. Although there are manufacturers that design and build bass speakers larger than18 inches, they just are not needed in the worship music world. Besides the variety of sizes, you can get your subwoofers self-powered (with built-in amplifiers) or non-powered. Personally, I would go with self-powered subs.
Even if you have a pair of non-powered speakers for your mains, you can add a powered sub without a lot of drama. Of course, this may depend on your mixing console. If you have a mixer with left and right outs plus a mono out, you can use the mono out for a sub send. I actually like to drive my subs with a separate out. It just gives me more control of the overall bass output.
So, let’s look at your sound system. You are either adding bass bins to an existing system or designing a new one with subwoofers in it. Two things to consider when designing a new sound system — or improving an older one — are, first, what type of music is played during the worship? Secondly, how many people does the church seat?
Some Different Examples
Let’s say you have a 1,000-seat church and every Sunday you have a full rock band playing worship music. In this worship house (along with the main speakers) I would use two bass bins — each one loaded with an 18-inch subwoofer and powered by 800 to 1,000 watts per bin. As noted, it takes more watts to push bass frequencies than mid or high frequencies, so a 1,000 watt sub is not crazy or over-the-top in terms of power. It would be just about how much power you will need.
As for my preference for self-powered subs, I see the fact that you will not need a crossover — a piece of outboard gear that is used to divide frequencies in low and high or low, mid and high — as a big advantage. Many self-powered bass bins have crossovers built into the onboard electronics. That makes adding subs to your existing system or designing a new system with subs a little easier.
Subs generally reproduce frequencies from about 40 Hz to 125 Hz. Their job is to just give that low-end some punch and separation. Back to the worship room scenarios, my home church seats about 250 people, and we have a rockin’ worship band. Along with a pair of mains speaker and a pair of close-in near-field speakers, we have one 15-inch non-powered sub which is driver by an 800 watt amp. Of course, the signal gets to the amp via an outboard crossover. The system actually works very well for the space. One of the reasons is the acoustics of the room itself. Of course, acoustics affect every worship room. But we will cover that subject at another time.
Another Scenario
Let’s look at a different example. In this case, you have a 500-seat church and you usually have a choir, keyboards and acoustic guitar every Sunday. I would use a single 18-inch or one or two 15-inch bass bin boxes. If you don’t have a band with drums and a bass player, you don’t really need a lot of low-end power. That said, I do like the way a good subwoofer rounds out the sound of a keyboard or piano. Personally, I am leaning toward the two 15-inch bass bins, mainly because I like bass and I like to spread my bass around.
In actuality, low-end frequencies are not very directional. They will get to just about everywhere in your worship room. That means you don’t have to have your subs in any particular area. I personally like them on the same side of the room as the main speakers but I have installed subs in other location in a sanctuary with very good results. If I haven’t described your church situation, don’t worry, subwoofers can find a home in just about any audio installation.
I have installed systems as small a pair of 8-inch two-way mains and one 12-inch bass bin. That system was perfect for the sanctuary in which it was installed, and it sounded awesome. The key takeaway here is that if you just add subs to your current audio system indiscriminately, you will not improve the sound quality as much as if you deliberately and methodically enhance the low end. If you’re new to all this, I would recommend bringing a professional out to evaluate your current system and decide what path to take from there.
