The nickel TLM 170 R Large-Diaphragm Multipattern Condenser Microphone from Neumann is a stereo set of two large-diaphragm, multipattern condenser microphones that features FET 100 technology, a balanced, transformerless output stage, low self-noise, and an impressive dynamic range.

Five directional characteristics are selectable by means of a rotary switch. In the sixth position, marked "R," the directional patterns can be controlled remotely with the included N 248 power supply. There is no special cable necessary for this purpose. The microphone has at its rear a 10 dB attenuation switch for extremely high sound-pressure levels, and a high-pass filter to suppress structure-borne noise. A second switch at the rear enables the mic to attenuate the frequency response below 100 Hz to suppress undesired structure-borne noise.

The TLM 170 R can be used for many diverse applications in professional recording studios, in broadcasting, film and television, and for semi-professional productions.

The large-diaphragm capsule inside the head grille has a very smooth frequency response for all polar patterns over a wide acceptance angle. The curves are flat and parallel to the 0° frequency curve up to 10 kHz within an angle of ± 100°. As a result, the TLM 170 R has a very even diffuse-field response for all polar patterns. This is important in a reverberant environment, as more reflections arrive at the microphone from different directions. The acoustic information is not affected in its tonal quality when recorded by the microphone. This characteristic is achieved without resorting to corrective-resonance effects.

The microphone maintains an great impulse response reproducing transient music and speech without any coloration. The capsule is elastically mounted to avoid any structure-borne noise that could interfere with its operation.

When compared to the standard cardioid pattern, the hypercardioid characteristic suppresses sound from the side more efficiently. The wide-angle polar pattern is especially useful to record large sound sources. The N 248 controls the polar pattern remotely by varying the phantom voltage. The range is ± 3V of the nominal 48V value. The rotary switch on the microphone must be in the position R, remote control. In this switch position the TLM 170 R microphone analyzes the absolute value of the phantom power and selects the corresponding polar pattern. A standard 3-pin microphone cable is used, similar to the microphone's conventional operation. Cable lengths may be up to 1000'.

With TLM technology, the usual output transformer is replaced by an electronic circuit. As with traditional transformers, it ensures good common-mode rejection, and prevents RF interference, that may influence the balanced audio signal.

A tilting side bracket to attach the microphone to booms or stands is included. The bracket is equipped with rubber elements that effectively protect the microphone from mechanical shock. If necessary, it can be mounted on the other side of the microphone as well. When using the IC 4 cable, the bracket and its holder need to be removed. The microphone can then be connected to the swivel-mount connector of the cable.

All exposed surfaces of the capsule, including the diaphragms, are at ground potential. This technology makes them highly immune to electrical and atmospheric interference and contamination through dust particles.