GRAMOPHONE. The major portion of the improvement introduced has dealt with the co-ordination of the results obtainable with the new equipment and the production of a proper artistic effect. As might be expected, this has dealt mainly with the study of the proper acoustic conditions in the space in which the sound is produced.
The early recording by the new process was done largely in small rooms in which the acoustics were well controlled. It was soon found that the acoustic properties of small rooms were totally unsuited to the proper artistic effect when dealing with those types of music which are usually produced in large audi toriums or theatres. A large amount of experimenting was, therefore, done, which showed definitely that the best way to record symphony orchestras, choruses, opera selections, etc., was to place the artists in a small theatre or auditorium, and to arrange them in much the way that they would be arranged were an audience present.
The early experiments indicated two major difficulties with this type of arrangement. First, there appeared to be excessive reverberation; and, secondly, it was difficult to find a situation for the microphone or pick-up device at which interference was not present in certain frequency regions. (That is, at certain
parts of the musical scale.) It was found by experiment that the time of reverberation, as in small studios, should be approximately •7 to .8 of that re quired for audience listening. Also, it was found that the portion of the space in which the sound is produced should have surfaces of more reflecting ability than the average indicated for the audi torium, while the space in which the microphone or pick-up device is situated should be as dead or well damped as possible.
In the field of phonograph reproduction, there have been no major developments within the last few years. The trend of the improvements introduced has been towards the use of electric methods rather than mechanical. The wide range of both fre quency and loudness, which can be obtained by the use of electric methods and the simplicity with which the loudness can be con trolled, is probably mainly responsible for this trend. While for small, low-priced instruments, it is still possible to obtain more faithful reproduction with the mechanical machines, the im provements in the electric methods of reproduction have caused this method to take precedence in the higher priced field.