KM 100
Application Guide
INTRODUCTION
Foreword
The KM 100 miniature microphone system debuted in 1988; down through the years, it has been expanded with accessories, turning it into a universal, modular system that adapts well to individual requirements. This “Application Guide”, which is intended as a supplement to the KM 100 product catalog, explains the modular construction of these microphones and numerous sample applications.
This brochure lays no claim to exhaustiveness – the possibilities inherent in this modular system are simply too varied for that.
Many combinations have been developed by our customers themselves in practical settings. Some of these ideas have since found their way “into series” and are presented in this brochure. Think of it as a source of inspiration for your own approach to using the KM 100 system creatively.
As a supplement to the standard accessories available, Neumann can also manufacture variants and special parts according to customer request, thus additionally expanding the range of applications for this system.
The Foundations of the Modular System
The most important prerequisite for the modularity of this miniature microphone system is the ability to separate the microphone capsule from the so-called output stage. Electronics built right into the microphone – placed right after the capsule – ensure optimum decoupling of all subsequent accessories or cables, so that they have no influence on audio signal quality.
Because of the electronics that they contain, these capsules are known as active capsules (AK). There are seven different active capsules with varying directional characteristics: AK 20, AK 30, AK 31, AK 40, AK 43, AK 45 and AK 50.
Active Capsules
The required level of miniaturization was achieved through the use of highly advanced hybrid components that permit a very high packaging density.
Section of Capsule with Hybrid Module Visible
The flexibility of the KM 100 system is due especially to numerous electrically passive accessories that can be connected between the capsule and the output stage, and an extensive range of mechanical accessories for mounting and positioning.
For the most part, Neumann accessories are freely combinable, since they are provided with both a 5/8” internal thread (US standard) and 3/8” and 1/2” internal threads (EU). This adaptation is made using a reversible adaptor that screws into the 5/8” threads. (Exception: The SGE 100 has only a 3/8” thread and an M6 bolt respectively).
First, however, let us consider the various electrical connection possibilities available.
Electrical Connection Possibilities of the Microphone
In the simplest case, an active capsule is connected directly to the output stage of the KM 100. This results in a compact miniature microphone that measures 92 mm in length – for example, the KM 140:
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AK 40 |
KM 100 |
KM 140 |
In many situations, especially for spoken voice applications, it is advisable to filter out low-frequency noise electrically. This is done with the help of the KM 100 F filter output stage, which can be used instead of the normal KM 100 output stage and has a slide switch permitting selection of an 80 Hz or 120 Hz cutoff frequency.
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AK ... |
KM 100 F |
Numerous strictly passive, mechanical accessories can be inserted between the capsule and the output stage.
KVF ... KA
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SG-AK |
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LC 3 KA |
AK ... |
KM 100 (F) |
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SMK ... KA |
MF-AK
There are also various ways of connecting the microphone to the mixing console.
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INTRODUCTION
Connecting to a Mixing Console with Phantom Power
At the XLR connector, the KM 100 and KM 100 F output stages have the same outer diameter as an XLR plug. In the simplest case, the output stage is plugged directly into the XLR input jack on the mixing console:
AK ... + KM 100 (F) + Mixing Console
or connected via an XLR microphone cable:
AK ... + KM 100 (F) + XLR 3 Cable + Mixing Console
Connecting to a Mixing Console without
Phantom Power / Power Supplies
If phantom power is unavailable, then an external power supply unit is inserted between mic capsule and mixing console. The following power supply units are available:
N 48 i-2: Plug-in mains unit, two-channel, 3-pin XLR connectors BS 48 i: 9 V battery operation, one-channel, 3-pin XLR connectors BS 48 i-2: 9 V battery operation, two-channel, 5-pin XLR connectors
The complete signal path then looks like this:
AK ... + KM 100 (F) + (XLR 3 Cable) + N 48 i-2 / BS 48 i +
XLR 3 Cable + Mixing Console
or
2x AK ... + 2x KM 100 (F) + AC 21 + BS 48 i-2 +
AC 20 + Mixing Console
All the necessary adapter cables for connecting to portable recording equipment with 3.5 mm or 6.3 mm jacks are described in our accessories catalog.
Power and Matrixing
Highly compact, portable solutions are possible with the help of the MTX 191 A matrix amplifier. It powers two active capsules directly, using the AC 30 adapter cable, with no output stages required. The MTX 191 A can be powered via phantom power or by an internal 9 Volt battery. In addition, both signals can be matrixed from MS (= middle/ side) to XY- (= left/right) format. Moreover, the MTX 191 A incorporates a switchable high-pass filter with cutoff frequencies of 80 and 160 Hz and a switchable 10 dB attenuation.
2x AK 20 + AC 30 + MTX 191 A + AC 20 + Mixing Console
For this application, too, there are numerous adapter cables for connection to portable recording equipment with 3.5 mm or 6.3 mm input jacks.
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AK ... |
KM 100 (F) |
Mixing Console |
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AK ... |
KM 100 (F) |
XLR 3 Cable |
Mixing Console |
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AK ... |
KM 100 (F) |
(XLR 3 Cable) |
N 48 i-2 / BS 48 i |
XLR 3 Cable |
Mixing Console |
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2x AK ... |
2x KM 100 (F) |
AC 21 |
BS 48 i-2 |
AC 20 |
Mixing Console |
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2x AK 20 |
AC 30 |
MTX 191 A |
AC 20 |
Mixing Console |
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TABLETOP APPLICATION
ne of the most varied applications is as a speaker’s microphone on a table. Usually the microphone should be placed so that it is inconspicuous or even invisible, especially in television, while delivering optimum signal quality. Moreover, body noise and wind noise should be suppressed effectively. For this reason, many variants are offered depending on the optical and acoustical requirements and budget.
The preferred capsule for speech applications is the AK 40 cardioid, or, in rooms with strong reflections, loud environments, or strong table reflections, the AK 50 hypercardioid. With the latter, it is also a question of whether the specific geometry (incident angle) of the table reflections is such that the hypercardoid offers the best cancellation (± 120°).
The AK 45 “speech cardioid” is the right choice for extremely close distances (< 10 cm). This mic capsule has a frequency response that has been optimized to deliver balanced response even at extremely close distances.
To pick up several speakers at the same time, for example, in the context of a round-table discussion, the AK 43 wide-angle cardioid can be used to cover a wider angle or the AK 30 omnidirectional can be used to cover an omnidirectional field. If there are only two speakers, then occasionally the bidirectional AK 20 with figure-eight characteristic, which completely suppresses sounds coming from the side, is set up between the two speakers.
If the microphone is positioned very close to the speaker, then windscreens and pop filters should be used (see “Pop Screens and Windscreens”).
Small Setups
A typical example for use of small setups is miking a television news anchor. The mic should be inconspicuous, and yet its directional pattern should reject noise and possible table reflections.
The Smallest Variant
The simplest and most cost effective variant is to use the included SG 21/17 mt clamp to mount the entire microphone on a table stand, for example, the MF 3 table stand.
KM ... + SG 21/17 mt + MF 3
The Simplest Variant
The smallest of all solutions is embodied by the MF-AK table stand. The active capsule screws right onto the swiveling headpiece, is alignable in the horizontal and vertical planes, and connects to the KM 100 output stage via the permanently attached cable. The cable exits at the side or below, making it possible to run the cable through the table where it is hidden by the stand itself.
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The microphone stand rests on a soft cellular rubber disk that dampens body noise.
AK ... + MF-AK
The following combination, in which the active capsule with extension cable LC 3 KA is attached to the SGE 100 stand mount, is not much bigger. The MF 2 table stand has the same small diameter as the MF-AK and also rests on a shockabsorbing cellular rubber pad. Moreover, it incorporates rubber mount for additional suppression of body noise.
AK ... + SGE 100 + LC 3 KA + MF 2
The Flexible Variant
If a short gooseneck is desired in order to keep the capsule away from table reflections while still permitting a large range of angle adjustments, the SMK 100 KA gooseneck can be used. The cable runs through the inside of the gooseneck to the base, where it exits from the side
above the MF 2 table stand.
AK ... + SMK 100 KA + MF 2
The Failsafe Variants
If two microphones are needed in the same place or one is to serve as a “reserve”, it is sometimes desirable to double microphones. Special mounts are also available for this.
The DS 21 mt double mount makes it possible to mount two complete microphones on one table stand, for example, the MF 3. The MF 3 table stand also rests on a shock-absorbing cellular rubber pad.
2x KM ... + DS 21 mt + MF 3
The SMK 100-2 KA double gooseneck is offered for most flexible solutions.
2x AK ... + SMK 100-2 KA + MF 2
With the capsules aligned accordingly, this setup can even be used for speakers who are seated opposite one another.
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