LAVALIERS: AN OVERVIEW

A lavalier is generally defined as being any small microphone designed to be worn on a person's body. The majority of lavaliers are omni directional (they pick up sound in all directions). Most lavaliers are electret condenser designs, which are highly sensitive, full spectrum, and miniature.

	Form floating loop and tape down the leading inches of cable.

An often-misunderstood characteristic of lavaliers is their "reach", or ability to pick up distant sounds. This is a function of self-noise; the quieter ones will reach further. In some instances, such as in noisy environments, this is undesirable.

Lavaliers are usually placed on the performer so they always have a "close up "sound. Some of the problems that may be encountered with lavaliers include the difficulties of hiding them under clothing, the ensuing clothing noise, and wind noise.

Lavaliers may be used as either "hardwire" or "wireless". Hardwire means that the actors are physically connected via an audio cable to the mixing panel or recorder. Wireless refers to connecting the lavalier to a small transmitter and transmitting the signal back to a receiver, which, in turn, feeds an audio signal into the mixing panel or recorder.

Regardless of whether the signal is conveyed by wire or radio, the microphone capsule remains the same. It is only the connectors and power supply that change.

Historical Background:
The first modern lavalier to find acceptance by the professional community was the Sony ECM-50, introduced a generation ago (and since replaced by the ECM-55). The sound quality of the ECM-50 was characterized as very full with strong bass response. Newscasters felt that it gave their voices a rich, mellow quality.

The ECM-50 can be described as a proximity lavalier, as it did tend to favor or isolate voice from background. Also, there is a very pronounced drop-off when the source drifts off-axis (such as turning the head over the shoulder, away from the mic).

The excellent bass response of ECM-50 proved to be a disadvantage when working outside the studio. It was sensitive to wind noise and background rumble. Nevertheless, the ECM-50 was the most popular lav available for its day.

The later years brought a handful of new entries into the field. For instance, the Tram TR-50 astounded the industry with its diminutive size, without sacrificing quality. Sony updated their lavalier line, Sennheiser developed their impressive MKE 2. Professional Sound Corporation designed and built the MilliMic production lavalier, The Sonotrim STR-ML gained favor for use with production wireless and Sanken introduced the COS-11PT. The newcomers in the arena of high quality lavalier mics are the elegant DPA 4060 and the super-miniature Countryman B-6.

So Which Lavalier Should You Own?
Each has its advantages and disadvantages. Every sound mixer has a personal preference based upon experiences, budget, and individual needs. Many professional mixers stock an assortment of lavaliers in their packages. Just like camera lenses, there is no one microphone that is best suited for all situations.

Omni Lavaliers
* The Tram TR-50 sound is more open sounding than many lavaliers and cuts very well with boom mics. The Tram has been the most popular lavalier in feature film work for many years. It comes with an assortment of very useful mounting clips and has proven to be a very reliable tool for sound recordists.

* The Sonotrim STR-ML lav is a variation of the Tram mic with a slightly less severe presence peak. The Sonotrim is very popular for use with the Lectrosonics wireless systems. Many mixers will use Tram mics for their hardwire uses and Sonotrims for when they need to introduce wireless into the shot. The Sonotrims come with the same assortment of mounting clips that are provided with the Tram TR-50.

* The Sanken COS-11 has become the new Lavalier of choice for production sound mixers. The COS-11 is ultra small, ultra high output, and has recently taken the film and video industry by storm. The uniqueness of the Sanken lies in the newly developed unique vertical placement of the diaphragm for greater effective area within a much smaller casing. This mic sounds as close to a shotgun mic as any lavalier we have heard. The COS-11 is often purchased in the "red-dot" version for decreased sensitivity when being used with wireless mics. The LSC service department can also pad non red-dot mics down after the fact if the mic proves to be too "hot" for your wireless.

* The Sennheiser MKE-2 has had great success in the live theatrical market such as Broadway and touring theater applications due to its resistance to moisture (read: Actors sweat). Its overall toughness in harsh environments (read: any stage production) is due, in part, to a metal strand in its cable, which resists the common problem of capsule separation from the cable. Its overall sound quality is superb and its miniature size makes it very easy to conceal. It is also considered to be one of the premier lav mics for "plant mic" use.

* The Danish Pro Audio (DPA) 4060 lav is the priciest lav on the market. DPA has incorporated a unique double vent protection system together with water resistant materials to offer an exceptional level of moisture resistance. This is one of the smallest lavs on the market and yet it retains great sound and sensitivity. Another great feature of this mic is the provided protective caps that can be used to modify the high-end frequency response depending on the placement of the microphone on the body. The DPA line of mics also has a high SPL rating, making it well suited for both film and theatrical applications.

* The PSC MilliMic boasts miniature size, very high output, a low inherent noise floor and exceptional shielding against electromagnetic interference. The soft, flexible and non-reflective matte finish of the MilliMic's cable will also better isolate handling noise and keep the mic unobtrusive on camera. It blends nicely with overhead booms. This mic has also found a very good niche in the Television News market. The MilliMic is moderately priced and packaged with a unique and versatile array of mounting hardware.

* The Countryman EMW series of lavaliers are among the most water resistant mic's on the market. They sound great and are available in an assortment of colors and connector types for your wireless. Countryman's B-6 has also gained popularity due to its incredibly small size and the assortment of included caps, which allow you to tailor the frequency response of the mic capsule.

Directional Lavaliers
What about directional lavaliers such as the Sony ECM-66 and the Sennheiser MKE 104? From a production standpoint, the use of directional lavaliers has not proved practical. Directional lavs have to be pointed precisely in the direction of the sound, and often times that is just not feasible when wiring actors with hidden mics. Also, directional lavalieres stop being directional when their side ports are blocked by clothing and mounting tape, making them difficult to hide under wardrobe.

The most popular application for directional lavalieres has been for public address, where feedback can be a real problem for sensitive, omni directional lavaliers. As long as there are no loudspeaker enclosures directly over the podium area, cardioid lavaliers are very effective in isolating speech from feedback and ambient noise.

In summary, there is no one lavalier that is best for all situations. Your choice of lavaliers should include a wide range of types of patterns, frequency responses and shapes to accommodate the different situations that may arise. An actor with a low, muffled "Bruno Kirby-type" voice may benefit from a lav with a bit of a mid-range peak for clarity. A thinner voice may be enhanced by a bit of a low-end boost. The best mic for the job changes with each job. The right mic for this shot or job may not be right for the next one.

Noise Considerations:
One of the ever-present difficulties of hiding lavaliers under wardrobe is clothing noise. In actuality, there are two different causes of "clothing noise": Contact noise and acoustic noise.

Contact noise is the result of garments rubbing against either the mic capsule itself or the leading few inches of cable (equally sensitive to friction). Contact noise can usually be controlled - if not completely eliminated - by careful positioning and taping down of the mic and cable.

Begin by securing the clothing on both sides of the mic capsule. This can be done by sandwiching the mic between two sticky triangles of cloth, camera, or gaffers tape. Form these triangles by folding a few inches of 1" wide tape corner over corner, similar to folding a flag.

Form sticky triangles to secure mic on both sides.

By immobilizing the mic between both layers of clothing, you have eliminated the possibility of either layer of clothing rubbing against or flapping onto the microphone.

If the lavalier must be positioned between skin and clothing, or attached directly to the skin, then a professional medical/surgical tape should be used against the skin.

Once the mic capsule has been secured, the next step is to form a strain relief for the thin cable. Make a small loop just under the mic capsule. In the case of very sensitive mics, such as the Sony ECM-77, the Sennheiser MKE 2, and the Sanken COS-11, make the loop go around twice. Tie a small thread or use a thin strip of camera tape (sticky side out) to preserve the loop. Tie the loop loose enough so that it can "breathe" (change diameter to absorb tugs).

Apply a few inches of tape along the cable below the loop. Any tension on the cable will be absorbed by the garment, rather than by the microphone (which is somewhat isolated by the floating loop).

The remainder of the mic cable can be run under clothing and can terminate either at the waist or the ankle. The end of the mic connector should be secured so that it does not dangle freely.

During a take, it becomes a simple matter to plug in an extension XLR cable. Afterwards, the talent can easily be disconnected so that he or she is free to roam around.

When using an external "tie clip", it is still important to think in terms of creating a strain relief. Loop the thin cable up and under the tie clip, forming a semi-circle, and passing through the wide hinge of the clip. Continue the loop behind the garment, and bring the cable around downward, thus completing the circle. As the cable loops downward, it should be inserted between the jaws of the tie clip and the back of the garment. Hide the balance of the cable behind the wardrobe.

	Proper use of horizontal mounting clip.

Not only is this arrangement more pleasing to the eye than a dangling cable, but also the floating loop of the cable isolates the mic while the grip of the tie clip serves as a strain relief.

Acoustic clothing noise is the sound generated by the clothing itself as garments or layers rub against each other when the actor moves. Noise is much more prevalent from synthetic fabrics than from natural cottons or wools. There is no simple remedy, only prevention, so it is wise to consult early with the wardrobe department.

However, here are a couple of tricks that may help. Anti-static sprays, such as Static Guard™, will reduce static electric discharge, clinging, and reduce friction. Dry silicon spray lubricants sometimes help, but be careful of staining. Stiff or starched clothing can be softened with water or alcohol (make sure the colors don't bleed). Saddle soap, silicon, or light oil can take the bite out of hard leather.

Another noise problem common to lavaliers is that of wind noise. Manufacturers usually supply small foam or metal mesh windscreens with their lavaliers, but these are usually more effective against breath pops than against outdoor gusts of wind.

Lavaliers used under clothing have the advantage of being partially shielded from the wind, but may still require added protection.

Clothing rubbing against windscreens can be extremely noisy, so great care must be taken when using hidden lavaliers out of doors. Surrounding the windscreen with sticky tape and securing it to both layers of clothing, as you would a bare mic, will reduce the friction noise. However, the tape may destroy a foam windscreen when it is removed! Inexpensive, expendable windscreens can be made by wrapping the mic in acoustafoam, or by pulling the foam booties off of video cleaning swabs.

Cheesecloth over a mic works very well against wind. Another Hollywood variation is to snip the finger tips off children's woolen gloves, and pull the wool tips over a lavalier wrapped in foam or cheesecloth.

We hope these tips are of help to you in your pursuit of better audio. LSC is the professional's choice for audio gear and support. Call us for more information and to fill any of your professional audio needs. For recording sound on location, call Location Sound Corporation.

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