Recording Speech Using Lavalier Microphones
Lavalier microphones or lapel mics are small clip-on mics that are extremely useful for recording interviews and speeches. Because of their size, they’re easy to handle (and hide) and deliver great sound quality.
Here’s a simple guide to help you choose the best one for your recordings –
Types of Lavalier Microphones
There are 2 basic types of lavalier microphones available:
1. Omnidirectional Lavalier Microphones
These are the standard lavalier microphones used for indoor recordings. They have a spherical field of vision, which means they capture sounds from all directions (giving priority to the closest sound source).
This is useful if the person wearing the microphone turns their head while speaking. In unidirectional microphones head-turns cause a dip in volume, but an omnidirectional microphones there’s no such problem.
Omnidirectioanl lavalier mics are smaller in size compared to unidirectional lavaliers and produce better sound quality in general.
2. Unidirectional Lavalier Microphones (a.k.a Cardioid)
These are unidirectional lavalier microphones that are useful in noisy surroundings. They have a narrow field of vision (generous in front, limited on the sides and almost zero at the rear) because of which they only capture sounds directly in front of the diaphragm.
This is great to cut out surrounding noise and makes them good for outdoor recordings but it also makes them sensitive to head-turns.
Both omnidirectional and unidirectional lavalier microphones come in wired and wireless models.
Wired lavaliers are economical, give great sound quality and are ideal for audio recordings. Some say that the lowest cost wired microphones sound better than the most expensive wireless microphone system. That may be an overstatement, but you get the picture.
The wireless microphones are comparatively expensive but look neater on videos and allow more flexibility of movement.
Placement of Lavalier Microphones
Lavalier microphones are called lapel microphones because they are placed on the person of the speaker, close to the throat and usually hidden under folds of clothing (when making videos).
If you’re using a wired microphone, remember that any movement of the wire will be captured by the mic. To minimize this noise, secure the wire with clips before starting a recording.
The trick is to find the right spot where the microphone is adequately secured yet the diaphragm isn’t masked by clothing.
The placement is particularly important in unidirectional lavalier microphones. Because of their narrow field of vision, if a unidirectional lavalier microphone is placed too close to the throat, the variation in volume can be quite high with head-turns. Placed too low, the voice can be too thin.
The ideal distance is 5-7 inches below the chin. This is good for omnidirectional lavaliers as well. Ideally, you should test your microphone at varying positions and figure out the ideal ‘spot’ for your device.
Windscreens are necessary for lavalier microphones to avoid distortion in the recording due to plosives (wind blasts due to the speaker’s breath). They are also necessary in outdoor recordings for protection from wind.
Many people use omnidirectional lavalier microphones upside-down to avoid plosives. This doesn’t work too well in outdoor recordings though, and it’s definitely not advisable for unidirectional microphones.
You can put the mic under the speaker’s clothing (under a collar, behind a tie, taped under a T-shirt etc.) to create a windshield.
If the wind is not too strong and the speaker is not a heavy breather, you can use a simple foam cover for the microphone. For high-wind locations, use a fuzzy/furry cover.
Wired lavalier mics work on phantom power; the microphone capsule is attached to a small tubular power supply that terminates in a three-pin XLR connection. Wireless lavalier mics, on the other hand, need internal batteries that may last anywhere from 2-7 hours.
If you’re recording a sit-down speech or interview, you don’t necessarily need a wireless microphone, but if you do, remember to check the manufacturers specs and keep at least one set of extra batteries handy.
Wired lavalier microphones are available for $20.00 onward, the wireless versions are more expensive – starting at around $200.00.
You can get an Audio-Technica ATR3350 Lavalier Microphone or a Radio Shack Lavalier between $30-$90.00. A Sony ECM 55B Lavalier is expensive (around $300.00) but is worth the money for the high quality sound and sturdiness. This video will help you understand the difference in audio quality of the different types of lavalier microphones (the prices are a little out of date).
The next time you record a speech or an interview, do try using a lapel/lavalier microphone. It will immensely improve the quality of your recordings and consequently increase the accuracy of your transcripts.
P.S. Are you planning to record an interview using an iPhone? Here’s how you can use a lavalier with your iPhone Lavaliere Microphone for iPhone 4