American cinematographer (Jan-Dec 1957)

EX ELECTRIC CORPORATION! -SAN CARLOS CALIFORfNj NITOR CUt ^j|P OUTPUT V.U. METER: “volume unit” meter which indi¬ cates relative levels of sound during recording. 4* TRACK No2. TRACK No1 ^ DUAL TRACK MONAURAL RECORDING X _ . . . . y ' iiWillllltt: ..EXT. IBH RIGHT TRACK 4 /4 iirjn — LEFT TRACK 4 f . ~ . . “ STEREO OR BINAURAL RECORDING ( W-IWE heads') HEAD POSITION: diagram shows recording head position on tape for two types recording. half twist in tape and rewinding on recorder. *BASS REFLEX SPEAKER ENCLO¬ SURE — Type of extension loudspeaker cabinet frequently available as acces¬ sory item for tape recorder. Design employs a “port” or opening which greatly reinforces the bass, yet requires but a relatively small cabinet. BIAS — A high-frequency alternating current fed into the recording circuit to eliminate distortion. BULK ERASER — A 11(3 volt A.C. device used to erase an entire reel of magnetic tape at once without running it through a recorder. It uses a strong magnetic held which neutralizes the magnetic patterns on the tape. CAPSTAN — The spindle or shaft— often the motor shaft itself — which ro¬ tates against the tape, pulling it along at a constant speed on recording and play¬ back. * CERAMIC MICROPHONE — Inex¬ pensive piezoelectric type microphone supplied with many tape recorders which employs a ceramic element to generate voltages. Extremely rugged, it requires more gain than does a crystal microphone. * CROSSOVER NETWORK — Filter circuits for a multiple loudspeaker sys¬ tem which separates highs and lows and feeds each to the particular speaker de¬ signed to handle them. * CRYSTAL MICROPHONE — Inex¬ pensive piezoelectric type microphone supplied with many tape recorders which employs a natural crystal — usu¬ ally Rochelle salt — as its element. As the diaphragm moves, it causes the crys¬ tal to generate electrical voltages. Should be handled with care, however, and never exposed to heat. Provides best quality of all inexpensive microphones. CYCLES PER SECOND— The unit for measuring the frequency, or “pitch,” of any sound. Abbreviated “cps.” DECIBEL — Abbreviated “db”, it is a relative measure of sound intensity or “volume.” It expresses the ratio of one sound intensity to another. One db is the smallest change in sound vol¬ ume that the human ear can detect. DISTORTION — Any difference be¬ tween the original sound and that re¬ produced by a recording machine. Dis¬ tortion takes on many forms, and although it can never be completely eliminated, it can he reduced to a mini¬ mum in a good recording and repro¬ ducing system. Tape offers the maximum potential in distortion-free recording. DUAL TRACK RECORDER — Usu¬ ally a tape recorder with a recording head that covers half of the tape width, making it possible to record one track on the tape, then turn the reels over and record a second track in the oppo¬ site direction. Sometimes called a half¬ track recorder. DUPE — Sometimes called a “dub” or “dubbing.” A copy of a tape recording (Continued on Page 466) RECORDING “Extra Play” magnetic tape No. 190 all employ acetate film backings. AUDIBLE TONES — Sounds with wave frequencies which the average human can hear and which range from 30 to 15.000 cycles per second. * AUTOMATIC SHUT-OFF— Special switch incorporated in some tape re¬ corders which automatically stops the machine when the tape runs out, or in case of tape breakage. “B” WIND — Tape wound with oxide out. Seldom used today. Wind can be changed from “A” to “B” by putting ■ TAPE RECORDING equipment today is so simple to operate and so easy to acquire that many small film producers now do their own sound film recording. A thorough under¬ standing of how the equipment works and the function of the various recorder components is essential to successful results. AmEKICAN ClNEMATOGRAPHEK July, 1957 451