Selecting Overhead Microphones
Which pattern of condenser is best? Like everything else, it depends on the situation.
Narrower patterns, such as shotguns, have greater reach but exhibit more reverberation in a closed interior. For that reason, shotguns are preferred for exterior use or sometimes for use in a very dead soundstage. Besides a build-up of echo in an interior, a shotgun used overhead tends to be physically unwieldy in terms of headroom. Their narrow pattern also makes cueing from actor to actor very critical.
Shotguns, like telephoto lenses, will compress the background in terms of the foreground. In a photo, a distant sunset will appear very large and very close to a foreground sailboat. Similarly, shotguns will magnify background sounds and ambiance in relation to the subject. That is why the best way to utilize a highly directional microphone is with nothing behind the subject (i.e. the mic looks down at the subject, "seeing" only quiet dirt past it; or aimed upwards at the subject, seeing only silent sky). Aiming a shotgun horizontally should be avoided, except for miking certain sound effects.
Wider pattern condensers (cardioids) provide the mellowest sounds in terms of reverberation or room echo, but also have the shortest effective range. They must be kept relatively close to the actors in order to isolate the dialogue. However, since the cardioids are often used in cramped interiors with low ceilings, excessive head room is not usually a problem!
In between the wide cardioids and the narrow shotguns are the wide hypercardioids and the narrower hypercardioids. Their selection would be a trade-off between mellowness versus effective reach.
In addition to echo and reach, another factor that comes into play when selecting a boom mic is that of spread. Scenes involving tricky blocking and/or multiple actors might be better served by a mic that does not require as critical a targeting, even though it would be a compromise against reach and punching the dialogue.
One very useful trick in balancing a strong voice against a weak voice is to take advantage of the microphone's natural pattern. Favor the weak voice on axis, and let the strong voice strike slightly off axis.
A word about wind noise. Foam slip-on windscreens should always be used on interiors, since condensers are sensitive to even the most minute air movements. Out of doors, use a blimp style windscreen (Rycote, K-Tek, Rode, Sennheiser). Wind tends to gust unexpectedly, and simple foam is ineffective against anything more than a wisp of a breeze. For occasional exterior use, the new breed of hybrid slip-on fur over foam windscreens is an economical compromise.
Handheld microphones (performer or reporter mics) aren't used very frequently in theatrical production, but can have their uses. Dynamic mics are ideally suited for recording loud explosions, since their elements are virtually indestructible. A dynamic mic used relatively close-up (6 to 9 inches away) works excellently for isolating speech from a noisy background, such as for on-site voiceovers or talking head (mic seen on camera).
Staged scenes involving the use of a handheld mic (as a prop) should be recorded exactly that way, "as a prop!" Use a boom mic to actually record the voice, unless you want to be at the mercy of handling noise and inconsistent mic placement.
For man-on-the-street reporter interviews, provide talent with an omni-directional condenser (or electret) microphone. That will give you some consistency, irregardless of how well the reporter pays attention to cueing the microphone between himself and the interviewee.
Using Lavaliers
Correctly rigging body mics on talent requires time and tact. For at some point during the process, the soundperson will have to work inside of talent's clothes.
The microphone capsule itself can be secured either outside of clothing or hidden under wardrobe; the cable and connector will almost always be routed under wardrobe.
If the mic is going outside of clothing, then mounting clips can be used. The proper technique for using the tie-clasp style clip involves looping the cable from the head of the mic, like a "J," through the bend (hinge) of the clip. The cable continues up and around --behind the garment -- to complete the circle. As the cable makes its way down, it is clenched in the jaws of the clasp, thus providing a strain relief.
The remainder of the cable is run behind clothing so that the XLR connector can be secured at a convenient point, such as at the waist (belt or pocket) or ankle. Regular mic lines can then be easily connected or disconnected so as to free up talent in between takes.
If needed, the external lavaliere can be made quite inconspicuous by camouflaging it to match wardrobe. Colored marking pens can be used on small strips of tape and/or foam windscreens to subdue the appearance of the mic head and clasp. Alternatively, small patches of felt or cloth can be used to cover the mic. Remember that the (camouflaged) mic will be so tiny in the frame during a medium shot as to be nearly invisible. On close-ups, the camera can frame the microphone out completely.
A useful trick is to save the foam-tipped tech swabs used for head cleaning. These foam booties make excellent, expendable windscreens for mini lavalieres.
Hiding a lavaliere completely under clothing requires a lot more care and attention.
There are two types of clothing noise that one can encounter: contact and acoustic.
Contact clothing noise is caused by a garment flapping into or rubbing across the mic capsule. The solution is to carefully immobilize all clothing that may create this problem, by taping down everything on either side of the mic. One popular technique is to sandwich the mic in between two sticky triangles of tape (formed by folding a strip of tape like a flag, sticky side out).
Contact noise can also be caused when clothing rubs against the mic cable, so care should be taken in this area also -- even for external lavalieres. Form a loop near the mic for strain relief, and then apply a few lengths of tape to along the cable. Use double faced tape or sticky triangles to immobilize clothing as necessary, to keep it from rubbing.
Acoustic noise is that created from clothing rubbing against itself and generating a sound. Static Guardtm works well against this. A light spray of water can help soften starched fabric. Synthetic fibers tend to be much noisier than naturals, so they should be avoided whenever possible.
Rigging radio mics is a complex art in itself, but the most important point to remember is to never allow the mic line and the antenna to cross. Also, the antenna should be kept somewhat rigid, and never looped over itself. If the antenna has to run in a direction other than straight up or to the side, flip the transmitter unit around. (It is okay for the mic line to loop around, though.) A good way of keeping the antenna rigid is to affix a rubber band to the tip, and then to safety pin the rubber band to the clothing. This maintains a little tension but still provides a safe strain relief if the actor should bend over.
Check talent regularly. Tape tends to loosen due to moisture and movement. Costumes tend to be adjusted constantly, either by talent themselves or by the costume department.
Never assume that wardrobe personnel know how to rig either lavalieres or radios. Consult with them in terms of costume selection or modification so as to facilitate microphone and/or transmitter placement, but do not leave the actual wiring up or readjustments to them. Costumers worry about how the actors look, not how they sound.
