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unidirectional
For demonstrations it is essential that the performer's hands are kept free and also that mobility is possible. The lavalier microphone meets these requirements. "Wireless" mics are now available and eliminate the need for trailing connecting cable. Below is another type of unidirectional mic — a cardioid dynamic microphone equipped with floor stand mount.
Getting Most Out of Microphones
by Philip Lewis
X HE significant increase in the number of electronic recording devices, paging systems, language laboratories and public address systems in schools demands that teachers and audiovisual specialists be well grounded in their operation to insure quality results. In many instances, unsatisfactory recordings or distorted audio reproduction are due to improper use or poor selection of the microphone employed. This presentation points up in capsule form some important guidelines and techniques designed to overcome such problems.
Tips for Teachers i
1. Microphones are constructed for specific applications and must be selected for the particular job to be done:
a. Unidirectional— a imit sensitive to sound pickup from one direction only. Used with a single speaker or performer for recording or in an audience situation where it may be desirable to mask out crowd noises.
b. Bidirectional— a microphone with the ability tc pick up sound both from the front and back ol the unit. Lends itself to applications such a; interviews, dual verbal presentations and re corded dramatizations.
c. Omnidirectional (nondirectional)— a microphom sensitive to sound from all directions which cai be used in situations where a group of person: is arranged in an arc with the mic in the center as in a discussion or meeting.
d. Special microphones are available which com bine functions of the different patterns cited | Some are devised to be used in environment with unusual or severe requirements such as th< noise-canceling, contact and highly-directiona types.
2. It is well to run a check on a microphone to di termine its pickup pattern before using it for th first time. This may be done simply with a tap recorder. Establish the mic in a fixed position an at the proper height. Start the recorder and spea into the microphone starting at about six inch< away and increasing the distance by about s' inches for each successive test. This first seri< should be directly in line with the axis of the ii stnnnent. The second series of tests should incluo| deviations to the left and to the right of the a»l of the microphone, and the final series should V[ above and below the microphone axis. Chalklin'
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Educational Screen and Audiovisual Guide — April. 19*