Radio Broadcast (Nov. 1925-Apr 1926)

674 RADIO BROADCAST APRIL, 1926 Or, the pick-up of the three microphones, or any two of them, may be "mixed" to produce a musical balance better than can be secured on one (assuming no physical movement of the microphones). I insert this last qualifying clause because it is my opinion that in a studio of moderate size with experience and reasonable control in placing of musicians, one can do as good a job with one microphone as with a dozen. One microphone, properly placed, will give as satisfactory results on small ensembles, as any combination. The advantage of the multiple pick-up arrangements is the flexibility in adjustment secured when it is found during the first number of a performance that no one microphone is properly placed. If there is only one microphone, the choice is between entering the studio during the number and moving the transmitter, which always disturbs the artists and may cause a noise on the air, and letting it ride for that number, i.e. doing a bad job for five or ten minutes, and fixing things up during the first interval. In other words, the broadcaster has to choose between the electrical devil and the deep sea. But if he has a number of microphones independently mounted and controlled, his life is made a little easier. Suppose he encounters a soprano of unknown potentialities, with the usual piano accompaniment. If she sings very loud, it may be well to place her five feet from the microphone, say, while the piano THE MIXING PANEL AT WBAL Part of the standard 5000-watt equipment at that station. The mixing panel for various studio microphones is that av the extreme right of the illustration is two feet to one side. (See Fig. 1, position A). But if she sings softly, the piano will predominate with this set-up. Well, all you have to do is place your microphone B say three feet from the lady. As soon as she starts you will know which transmitter to use, and as you have control of both it is the work of only an instant to swing in the right one. Or, it may be convenient to combine the outputs of the two microphones. This, in brief, is the system used at wbal. With it there is much less excuse for poor musical balances, blasting, etc., than when only a single pick-up unit is available. The wbal announcement which has reached us merely explains the purpose of the system described, without giving the technical modus operandi. One way of doing it would be to use separate amplifier systems with individual gain controls of the type described in this department in the March issue ("Technical Routine in Broadcasting Stations: Monitoring"), the outputs being combined after two stages of low power amplification. This has the advantage of including a number of parallel chains: microphone plus amplification up to the five watt level, say; and if anything happens to one of the amplifiers or microphones, that particular system is cut out as a unit, leaving one or two others still functioning. It has the disadvantage of complexity. A method of using a multiplicity of microphones, individually controlled, "inputting," as Zeh Bouck says, to a single amplifier, is shown below under "Technical Operation of Broadcasting Stations: Multiple Pick-Up." KOA FROM koa, the big fellow in Denver, comes the news that the technical staff at that station are utilizing a "magic rug remedy" to keep public spea kers k 2' 1 Microphone "A" Microphone (>£) Accompanist y y X Soprano Soloist FIG. I within range of the microphone. The stunt is to place a small rug at the best pick-up location. After ten months' trial Alfred Thomas, the resident engineer in charge at koa, has this to say about his device: Not once has our magic device failed to turn the trick. Most any type of rug fills the bill if it is soft and of contrasting color with the floor. It should, however, be of small dimensions, say three or four feet. It is placed a few feet from the microphone, the distance depending wholly upon the voice of the person to be heard. Unconsciously, the speaker assumes a position on this rug before the microphone and there remains until his remarks are concluded. Subconsciously he regards this piece of floor-covering with its imaginary boundaries, as an island of safety, and he is disinclined to venture elsewhere about the stage. As a result, broadcast listeners are enabled to hear the talk in full. Otherwise, some of the speaker's comments would be lost to the invisible audience. Ministers, it is further stated, are the best behaved subjects before the microphone, while political speakers are the worst. How about the Rev. Billy Sunday? I have my doubts about the rug remedy if that acrobat-evangelist should be persuaded to broadcast. Dr. D. E. Phillips, a psychologist of the University of Denver, makes the remark that " koa's plan to prevent a speaker from taking gymnastic exercises on the lecture platform is indeed novel." With a heavy heart I must take issue with the eminent scholar of the U. of D. The stunt is a good one, but it is neither novel nor original. Public address operators in various parts of the country have been using it for years. In fact, if I am not mistaken, and I'm not, it was mentioned in the paper on public address systems by Green and Maxfield in the Journal of the A.l.E.E. for April, 1923. WJ/D THE sketch shows the layout of the new Chicago studio of wjjd, with transmitter at Mooseheart, Illinois. The new quarters consist of eight rooms — the