Mic Check: Options For Live Sound
There is no one microphone that fits every application. Understanding the trade offs between different types of microphones is the first step in choosing the best option for your event. So ask the following questions whenever considering which microphone(s) to use.
Is there a lot of environmental or ambient noise?
Will the microphone be stationery?
Does the user need both hands to be free?
Will the microphone be passed to other people?
Would a microphone cable create a tripping hazard?
Is it okay if the microphone is visible and present in pictures or video?
There are a number of different microphone styles and technologies out there, but this article will focus on the three most commonly used microphone systems in live sound applications; lavalier, wireless handheld and wired handheld microphones. Below is a quick comparison of these three types of microphones against five criteria.
Lavalier
Often called lapel mics as they are usually attached to suit jacket lapels during use, lavalier microphones have become increasingly popular at wedding ceremonies and interactive presentations for their discrete profile and hands-free operation. Lavalier microphone systems are comprised of three components:
Lavalier microphone - contains a small microphone, clip and cable that connects to the wireless transmitter. The microphone is clipped to the user's clothing close enough to their mouth that their voice can be picked up clearly.
Wireless transmitter - also known as a bodypack, this device takes the signal from the lavalier mic and sends to the wireless receiver. Can be easily concealed in a pocket and most come with a belt clip that allows it to be worn at the waist.
Wireless receiver - picks up the audio signal from the transmitter and allows for it to be sent to a mixer or speakers.
Since the microphones typically used in lavalier systems are omnidirectional in nature, because the user is not speaking directly into the microphone, these systems are best suited for indoor events or events that have little to no environmental and ambient noise. The user wants both of their hands to be free and they may wish to walk around. These are also the microphone of choice when discrete equipment optics are a priority. Lavalier mics look the best in pictures too because they are barely noticeable.
Pros
User has both hands available
Barely visible to guests and in photographs
Minimal training required
Great for nervous or fidgety speakers
Cons
Body and clothing friction sounds picked up by mic
More sensitive to environmental and ambient noise
Mic cannot be easily passed to multiple speakers
Requires more extensive live sound monitoring
Risk of wireless signal interference
Wireless Handheld
Similar to a lavalier microphone system, a wireless handheld system contains only two components with the microphone and wireless transmitter combined together in the same device.
These microphones are the most versatile and strike a nice balance between performance and convenience. They can be used equally well both inside and outside and manage a lot of environmental and ambient noise as the microphones typically used are directional in nature. The user doesn't have to deal with any wires anywhere; not on the ground that people may trip over nor running down their shirt to the bodypack in their pocket. One thing I love about the wireless handheld microphone is that I can easily place it somewhere in advance of when it needs to be used. This helps make seamless transitions throughout a timeline if anyone is giving remarks after an introduction. If the user is okay with the microphone in pictures and the user can spare to hold the mic in hand or be by a mic stand, this is the most convenient choice.
Pros
Allows easy transition between multiple speakers
No cables anywhere
Can be hidden or staged when not in use
Less susceptible to environmental and ambient noise
Cons
Requires a hand or a stand to use
Will be visibly present in pictures when in use
Requires proper mic placement by speaker for best sound
Nervous or fidgety speakers may accidentally mute or turn off mic
Risk of wireless signal interference
Wired Handheld
Since 1965, every US President has addressed the world with a wired microphone; specifically, the Shure SM57 dynamic microphone. Shure's Director of Corporate History, Michael Petterson, shared the White House Communications Agency's requirements:
"The President will speak in a variety of situations, both indoors and outdoors. Weather conditions will vary from very cold to very hot; very dry to very humid; no wind to high wind. Failure of the microphone in any of these situations is unacceptable. In addition, the microphone must endure physical abuse as it is packed and shipped throughout the world."
The SM57's older sister, the SM58, a wired handheld dynamic microphone with metal grill, has been world's most popular live music microphone for over 50 years. This was the microphone of choice for The Who, Paul McCartney, Buddy Guy, Led Zeppelin, AC/DC, Bruce Springsteen, Run-DMC and dozens of other multi-platinum artists. Musicians and sound engineers alike choose wired handheld microphones because they are so simple to use and a lot less can go wrong. There are no batteries to charge or replace, no risk of wireless frequency interference and little to no user training required. Wired handheld mics are the best choice for stationary applications where the user is not moving around. These could be a guitarist sitting down during a performance with the mic on a stand or someone sharing a speech or reading. The drawback of course is that you have a long cable and microphone visible in videos and pictures which can be a deal breaker when optics and event aesthetics are a high priority.
Pros
Easiest to control and monitor
Extremely rugged and reliable
No need to swap out batteries
No risk of wireless signal interference
Less susceptible to environmental and ambient noise
Cons
Requires a hand or stand to use
Both microphone and cable will be visible in photos
Less easy transition between multiple speakers
Microphone cable can be a tripping hazard
Sound Your Best
Even with the best microphone systems and environmental conditions at play, sound output might still be awful if someone inexperienced is using or monitoring the live sound. The following three tips can be applied to every event and you don't need to be a professional live sound engineer with tons of gear either to work out most of the kinks when using microphones.
Soundcheck
Every venue is different. Even the same venue setup with different floor plans or under different weather conditions can cause varying acoustics. Before each event, it is imperative to conduct a proper soundcheck. This entails a test of the sound systems full capabilities including microphone usage. During this check, walk around talking into the microphone to discover locations that cause feedback spikes. Generally, these are the areas directly in front of the speakers. Sometimes though, sound can gather in corners or parts of the room you least expect. An easy way to identify these spike locations is to mark them on the floor with tape. Conversely, you can mark sweet spots where the microphone sounds best and the user should stick around during use.
User Training
Before death and being forever alone, public speaking is consistently listed as people's number one fear. Naturally, people get nervous and may shake or move their hands frequently. To help ease the anxiety, it's important to go over proper microphone usage before showtime. When using a handheld microphone, keep it close to the mouth. When using a lapel mic, ensure that it has been applied properly to clothing which means the mic is neither too high nor too low. The further away from the user's mouth, input gain must be increased and risks producing mic feedback. Finally, the user should enunciate clearly and never stand directly in front of speakers.
High Pass Filter (Low Cut)
Most live sound mixers feature high pass filter, or low cut, buttons that trim off signal below a prescribed frequency. When enabled, only frequencies above the threshold are passed to the main mix. So for example, if the high pass filter is set to 75hz, signal below 75hz is removed and signal above 75hz remains. While the average adult male voice can go as low as 85hz, a decent microphone is also picking up frequencies as low as 50hz. By cutting out low-end frequencies outside the spectrum of most spoken word, you eliminate a lot of troublesome environmental and ambient noise that causes muddiness and feedback.
In closing, it's important to pick the right microphone for your event and sometimes that means asking the user what they prefer. Personal preference can trump the trade offs between microphone types, but when indecision presents you now understand the options.
-DJ ARIA