A Primer on Microphones
If you can’t hear the Word clearly, how can you worship effectively? If the worship sound is distracting, how can we join with others in worship?
While how microphones are used doesn’t affect the spiritual quality of worship, it makes a great difference in its technical quality and, if done poorly, can impede worship. To have the most technically excellent worship service, one must understand how microphones work and how to use them effectively.
Microphones pick up sound waves and turn them into electrical impulses. There are three main microphone designs: dynamic, condenser, and ribbon. Churches mainly use dynamic and condenser microphones.
- Dynamic microphones capture sound with a voice coil attached to the back of a diaphragm. When sound waves hit the coil, it moves a magnet inside of the coil to create an electrical impulse. These are rugged general-purpose microphones.
- Condenser microphones capture sound with a metalized diaphragm that vibrates near an electrical plate, creating an electrical impulse. These microphones are more fragile, but they reproduce a more natural sound. These microphones also require phantom power to pre-amplify the sound coming from them.
There is a lot of electrical engineering that goes into microphone design. If this interests you, there are many great resources on the internet. If not, at least know which type of microphone you have and what its main purposes are.
The main purpose of any microphone is to pick up sound waves, convert them to electrical impulses, and transmit them to a sound system. Microphones cannot discriminate among sound sources; they are designed to pick up all sound within range of the microphone. Therefore, manufacturers design microphones with different patterns of sound pickup. Once you understand these different patterns, you can set microphones to optimize their different characteristics. There are five main patterns of sound pickup, called polar patterns.
- The omnidirectional polar pattern picks up sound in all directions equally well: left-right, front-back, and above-below. Typical omnidirectional microphones include headsets and lapel microphones used by preachers.
- The cardioid polar pattern picks up sound directly in front of the microphone through about 131 degrees. It rejects sound at 180 degrees. This means it doesn’t pick up sound beyond the microphone, where the cord enters. This is probably the most common type of microphone polar pattern. These microphones can be used as handheld singing microphones or as a microphone for a choir, piano, or other instruments.
- Other polar patterns include supercardioid and hypercardioid, with uses similar to the cardioid but with a tighter pattern of sound pickup.
- One other pattern is the bidirectional polar pattern. This microphone picks up sound from both the front and back of itself, but not in between.
People often get confused between the type of microphone and the type of polar pattern. Both dynamic and condenser microphones can be purchased in any of the polar patterns.
How do we use microphones to achieve optimal performance? Different needs will determine what type of microphone to choose and how to place it.
- Usually preachers and other speakers will wear a wireless microphone on their body. The two main placements are a clipped-on lavalier or a headset worn over the ear.
- The better option from a sound operator’s standpoint is a headset. This puts the microphone closer to the sound source, gives more consistent sound quality, and minimizes clothing placement issues.
- These are usually a mini dynamic microphone with an omnidirectional polar pattern.
- Most of the time a handheld microphone is used in these situations.
- These microphones can be either wired or wireless.
- These are usually dynamic microphones with a cardioid polar pattern.
- These will be a church’s most-used microphones, so choose and spend wisely.
- A piano is one of the most difficult items to amplify.
- General-purpose dynamic cardioid mics can be used quite effectively. Place one or two in the body of the piano, but remember that cardioid microphones pick up sound in three dimensions at about 130 degrees. Placement matters.
- A couple of dedicated small-diaphragm condenser microphones with a tighter polar pattern such as supercardioid or hypercardioid might be better. These microphones will replicate a truer piano sound, and extraneous sound can be eliminated. Place them behind and above the hammers—one above the bass strings and one above the treble strings.
Many churches struggle with drum set volume. Some attempts to solve this issue include:
- Electric drum sets
- Drum shields or cages
- Sound-deadening materials
- The best solution is to have a drummer cognizant of acoustic needs.
- Larger churches and those recording their services often will need to use microphones with an acoustic drum set—one to pick up the bass drum and a second above the set to pick up the cymbals, toms, and snare. More microphones can be used, but it becomes difficult to isolate adjacent sounds due to polar patterns.
- Many churches struggle with drum set volume. Some attempts to solve this issue include:
Other musical instruments
- Electric guitar
- Electric guitar players like using their own amplifiers, but sound technicians need to have control of all of the sound on the stage. A good compromise is to place the amp in front of the player, facing the back of the stage, and to put a microphone in front of the amp to feed to the sound system. A general-purpose dynamic microphone works well for this.
- Bass guitar
- Similar setup to that of the electric guitar.
Acoustic Instruments such as guitar, strings, banjo, flute, trumpet, conga, djembe, or cajon
- A condenser microphone placed near the sound source can do a fine job of capturing the instruments’ sound.
- Many churches that record services like to have congregational singing and ambient sound on their recordings. It is also important to have microphones for the room’s sound if in-ear monitors are being used.
- Usually two condenser microphones are used. They should be placed close to the stage and pointed toward the congregation.
- Used for any group of musicians.
- Small-diaphragm condenser microphones mounted on boom stands are the standard choice for groups. Using as few microphones as possible is best—usually one for every fifteen people. Using more microphones than this can cause all sorts of interference among adjacent microphones.
- Place microphones at least three times further from adjacent microphones as to the closest person. Also, place the microphones above the tallest person in the back row. This allows most people to be equidistant from the microphones.
- Microphones can be flown from the ceiling above where they will be needed, but this limits their flexibility.
Microphone Design: Going Deeper
Basic Microphone Tool Box
Use these whenever possible. They are a great value, have fewer components that can fail during a service, and can be used in a variety of applications. The cost estimates provided in brackets are from 2016 and in U.S. dollars.
Shure SM58 ($100)
- Probably the most ubiquitous vocal microphone used in churches
- Dynamic cardioid microphone
- Used mainly for vocals, but can be used elsewhere
Shure SM57 ($100)
- Condenser cardioid microphone
- Use with acoustic instruments, hand drums, snare drum, guitar amps
Shure SM81 ($350)
- Small-diaphragm cardioid condenser microphone
- Use with choirs, groups of musicians, cymbals, acoustic instruments
Use in situations where a wired microphone would be inconvenient. A wireless microphone system has three main components: a receiver mounted near the mixer board, a transmitter located on or near the person, and a microphone. Early wireless systems were analog, but more current systems are digital. In the United States, frequencies in which digital systems operate are licensed by the Federal Communications Commission and are constantly changing. Be aware of this before purchasing digital systems.
Shure QLXD24/SM58 ($1,000)
- Wireless version of the SM58
- Used for singers and speakers in church
Shure QLXD24/83 ($1,000)
- Omnidirectional condenser lavalier microphone
- Used for preachers and worship leaders
- Also can be used for hands-free vocals or as an instrument microphone with additional clips
Countryman headsets ($400)
- Models for speaking and singing
- Come in different skin tones
(Shure microphones are used as examples because they are a great place to start with comparisons. There are many other great microphones from other companies, but there are also a lot of bad microphones. There are also good microphones used poorly.)
- Take a microphone survey in your church. Create a document, including photos, noting brands and models, microphone type, polar pattern, intended use, and replacement costs.
When purchasing new microphones:
Spend some time comparing and using them before you purchase them.
- Borrow from other churches.
- Rent from a reputable audiovisual company.
- Spend a Saturday trying different microphones in different placements. Create an event where multiple participants in a worship service can experiment in a non-stressful atmosphere. Include musicians and tech people. For example, mike a piano with different microphones in multiple setups. Then have a couple of different pianists play and listen while the tech person fades the different setups. Come to a consensus about which setup is most pleasing to the ear.
- Spend some time comparing and using them before you purchase them.
Last, remember that microphones are a tool for worship, there to help us glorify God and enjoy him forever.