Neumann.Berlin M 49 User's Manual
Contents
1. NEUMANN BERLIN gt gt THE MICROPHONE COMPANY M 49 The First Remote Controllable An important step forward in microphone technology was made with the model U 47 Its dual diaphragm capsule M 7 active on both sides made possible the first condens er microphone with switchable polar patterns The ques tion arose whether it could be possible to change the char acteristic during recording The relevant patent of Dr Grosskopf reads Thus the influence of exaggerated re verberation can be dimin ished the recording dis tance can be increased without getting a vague tim bre It is therefore an ur gent need for the recording technique to easily exchange microphones with different polar patterns The objec tive was to avoid an exchange of microphones or capsules and to remotely control the microphone s directional pickup pattern For this pur pose it is important that the output of the microphone remain fairly constant and independent of the selected pat tern The only switchable pattern microphone existing at that time the Neumann U 47 exhibits an increase in the output by 5 dB when switched from omni to cardioid In the cardioid position the rear half of the capsule in the U 47 was simply electrically disconnected As a consequence the output of the rear capsule and the attenuation of the front via the fixed parallel capacitance of the rear were avoided Comfortable pattern con trol fo2. g metal shock mount This meth od was incorporated later in most of the succeeding Neu mann microphones The M 49 was introduced to the German Radio Broad casters in 1952 Because of its unprecedented versatility it conquered the international recording studios rather quick ly Due to the innovative feature remote pattern control it found widespread application as the important main mi crophone above large orchestras Other applications were as a spot microphone for wind and string instruments for piano and as the favorite announcer s microphone Peg A a
3. r the new M 49 micro phone was achieved by keep ing both capsule halves con nected to the impedance converter with regard to the signal however insulated from each other with regard to the DC bias The front di aphragm is polarized with a constant voltage of 60 Vdc while the bias for the rear di aphragm is adjustable from O Vdc to 120 Vdc This al lows the polar pattern to be come variable between omni through cardioid to figure 8 maintaining a practically constant sensitivity The power supplies for the model M 49 microphones included a po tentiometer with a pointer knob and a corresponding scale we AN ys a 9 9 TERNARA jei LEE N aanRaANE NEY aiciejetstery slreishelste Stsispleteatelecintel4 y THE SEPA RGAe Eee hij TAES EA ey oe oe eee RERA mMARNEE MP ay SERE eel 1 azlobolstotsal qa 1 J pa x te Fe Available were portable and rack mounted versions of the power supplies Due to the many supply voltages the M 49 microphone was equipped with an 8 pole connector As tube in the early versions a directly heated triode MSC 2 made by Hiller was employed which later was succeeded by the Telefunken AC 701 k The mechanical construc tion provided means for the suppression of structure born noise The amplifier was mounted on a solid rubber disk mechanically isolating the amplifier from the housing In addition the microphone capsule was mechanically decou pled by means of a swin
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