Loudspeakers and amplification
Subwoofer vs No Subwoofer for a Church
Quick answer
Add a subwoofer if a bass guitar or a kick drum is in the service, because those sources live below 100 Hz where a 12 inch main produces almost nothing. Skip it for organ, piano, choir and spoken word, where a subwoofer adds room boom and no benefit.
Electro-Voice ELX200-18SP 18" 1200W Powered Subwoofer
$1,099.00 Specs and sizingAn 18 inch powered subwoofer with cardioid presets and fly points, at roughly half the price of the flagship options.
Best for: The first subwoofer a growing contemporary church buys
Check price on Amazon
JBL Professional EON715 Powered PA Speaker, 15 inch, 1300 Watt
$559.99 Specs and sizingA 15 inch full range main that carries a light band on its own, which is the honest alternative when no subwoofer line will be approved.
Best for: Contemporary worship in a mid-size room that has no budget line for subwoofers yet
Check price on AmazonThe test is content, not room size. If your service includes an electric bass or a kick drum, a subwoofer is the single most effective loudspeaker purchase you can make, because those instruments put most of their energy below 100 Hz and a 12 inch main produces very little down there. If your service is organ, piano, choir and preaching, a subwoofer will add nothing but boom.
This is also not a small-church against large-church question. A 120 seat church with a full band benefits more from a subwoofer than a 600 seat church with a pipe organ does. Run your service style and room through the subwoofer sizing calculator to get a count rather than a guess.
A subwoofer and a full range alternative
| Model | Price | Powered | Peak power | Woofer | Onboard DSP | Fly points | Coverage pattern |
|---|---|---|---|---|---|---|---|
| Electro-Voice ELX200-18SP 18" 1200W Powered Subwoofer | $1,099.00 | Yes | 1,200 W | 18 in | Yes | Yes | - |
| JBL Professional EON715 Powered PA Speaker, 15 inch, 1300 Watt | $559.99 | Yes | 1,300 W | 15 in | Yes | Yes | 100 by 60 degrees |
What lives below 100 Hz
Look at where your actual sources put their energy. That is the whole argument, and it takes one table.
A five string bass guitar reaches down to about 31 Hz and a kick drum to around 50 Hz, which is well below what a 12 inch main loudspeaker reproduces usefully.
| Source | Lowest fundamental | Needs a subwoofer? | Notes |
|---|---|---|---|
| Five string bass guitar | About 31 Hz | Yes | Low B is the reason |
| Four string bass guitar | About 41 Hz | Yes | Sounds thin without one |
| Kick drum | About 50 Hz | Yes | Impact is felt, not heard |
| Pipe organ, 16 foot stops | About 32 Hz | Sometimes | Often the pipes do it themselves |
| Grand piano | About 27 Hz | Rarely | Low notes are rarely used loud |
| Male speaking voice | About 85 Hz | No | High-pass it around 100 Hz |
| Choir | About 65 Hz | No | Nothing useful below that |
| Acoustic guitar | About 82 Hz | No | Low end is mostly boom |
Fundamental frequency is not the whole story, since harmonics carry much of what we identify as pitch. But energy below 100 Hz is what a subwoofer exists to reproduce, and only some sources have it.
Add a subwoofer if there is a band
Two things happen when a subwoofer joins a system, and the second is the one people do not expect. First, bass guitar and kick drum arrive with weight instead of as a click. Second, and more importantly, you can high-pass the mains around 100 Hz, which frees their amplifiers from the hardest work they do. The mains then sound noticeably cleaner at the same level, and vocals sit better. That improvement to the mains is often more audible than the low end itself.
Placement decides how well it works. Low frequency energy that gets onto the platform arrives in every open microphone and makes the whole mix muddy, which is why cardioid subwoofer modes exist. A cardioid-capable subwoofer keeps energy off the platform, and in a church that is worth more than raw output. See reducing stage volume.
One subwoofer is usually enough for a room up to about 300 seats; beyond that the sizing calculator will suggest two and a placement.
Skip the subwoofer for traditional and speech-led services
An organ, a piano, a choir and a lectern microphone have essentially nothing useful below 80 Hz that the congregation needs from the loudspeakers, and a pipe organ generates its own low frequencies acoustically far better than any subwoofer will. Adding one to that service does two harmful things: it excites room modes that make the sanctuary boomy, and it gives a volunteer a control that will eventually get turned up.
The money is better spent elsewhere. In a traditional church, the same budget put into acoustic treatment, better choir microphones or a delay fill for the back third of the room will do far more for what the congregation actually hears.
If the service is blended and a subwoofer feels like overkill, a 15 inch main is the middle answer: enough weight for a light band, no extra box, no crossover to manage.
Sources
- Electro-Voice published ELX200 series specifications
- Instrument fundamental frequency ranges from published musical acoustics references
Frequently asked questions
Will a subwoofer make our church too loud?
Not by itself. A subwoofer reproduces frequencies the mains could not produce, so it adds weight rather than level in the speech range. What it does do is make a loud mix feel more comfortable, which can tempt an operator to push the whole system. Set a level target and measure against it rather than mixing by feel.
Where should a subwoofer go in a sanctuary?
On the floor, near the platform, ideally centred rather than split into a stereo pair, since low frequencies are not directional and a centre position avoids cancellation between two boxes. Keep it off a hollow stage deck, which will resonate. If the platform booms, a cardioid mode is worth the extra money.
How many subwoofers does a church need?
Usually one up to about 300 seats with a band, and two beyond that or where the room is wide. More than two is rare outside large contemporary rooms. The sizing calculator works it from your room volume and service style, and it will also tell you when cardioid placement is worth doing.
Can I use a passive subwoofer with my existing amplifier?
Only if the amplifier has a spare channel with enough power and you have a crossover to feed it. A passive 18 rated 350 watts continuous wants roughly 700 watts per channel, which is more than a typical main amplifier has spare. Often a powered subwoofer is the cheaper route once the extra amplifier is counted.
What crossover frequency should I set?
Around 80 to 100 Hz for 12 inch mains is the usual starting point. Set the high-pass on the mains and the low-pass on the subwoofer to the same frequency, then check by walking the room. If there is a hollow or boomy spot near the crossover, moving the subwoofer usually helps more than changing the frequency.
Researched, not professional advice. This page is compiled from published manufacturer specifications, operator manuals, FCC rules, published standards and owner-review consensus, not hands-on testing. Sound system design, rigging loudspeakers overhead, and any electrical work are jobs for a qualified professional: have flown loudspeakers and their attachment points signed off by a structural engineer or a certified rigger, and have all wiring done by a licensed electrician to your local code. Wireless microphone rules change, so confirm the current FCC position before buying. As an Amazon Associate we earn from qualifying purchases.