AMS22
AMS24
AMS26
AMS28
GENERAL
AMS Series Condenser Microphones function as part of the
Shure Automatic Microphone System (AMS). AMS is a propri-
etary system that lowers background noise by automatically mut-
ing microphones when they are not in use. It offers superior perfor-
mance because it uses both the loudness
and direction of the
intended talker. This system is ideal for applications such as con-
ference rooms, legislatures, churches, courtrooms, broadcast
studios, and distance learning classrooms.
CAUTION
Only use AMS microphones with AMS mixers.
Connecting the microphone to other types of mixers or inputs
may damage the microphone.
IMPORTANT
Acoustical reflection from vertical and horizontal
surfaces to the rear or sides of the microphone
inhibits proper gating.
•
Place the microphone at least 1 meter (3 ft) from the wall
behind it, and at least 0.3 meters (1 ft) in front of any bulky
objects.
•
For AMS24 and AMS26 microphones, the grille must be at
least 203 mm (8 in.) above any horizontal surface.
•
For the AMS28, the microphone must be kept at least 76
mm (3 in.) away from any solid surface (table top or edge).
HOW AMS WORKS
Each AMS microphone contains two unidirectional cartridges.
One cartridge faces forward, towards the talker, and the other
faces in the opposite direction, away from the talker. The AMS
mixer gates the microphone while it continuously compares the
relative signal levels from each cartridge. Whenever the signal
from the front cartridge exceeds that of the rear cartridge by 9 dB
or more, the mixer opens the gate and allows signal from the front
cartridge to pass through the system. At all other times, the mixer
gate remains closed.
FRONT
CARTRIDGE
REAR
CARTRIDGE
AMS26
AMS MICROPHONE DESIGN
Figure 1
MODEL VARIATIONS
AMS 22 Boundary microphone
Low-profile, boundary microphone for installation on flat sur-
faces such as tables, desks, and lecterns. Operates like a hemi- or
half-cardioid microphone because half the cardioid pattern “disap-
pears” when the microphone is placed on a surface.
•
Low vibration and hum sensitivity
•
Hemi-cardioid polar pattern
•
Low profile design is unobtrusive on conference tables
•
Surface mounting eliminates comb-filter effects due to surface
reflections, allowing smoother frequency response
AMS24 Gooseneck Microphone
The AMS24 microphone is attached to a thin, flexible 381
mm (15 in.) gooseneck that is designed to be mounted to con-
ference tables, desks, and lecterns.
•
Low vibration and hum sensitivity
•
Frequency response tailored for voice
•
Cardioid polar pattern
•
Pop-filter grille reduces sensitivity to explosive breath sounds
AMS26 Probe Microphone
The AMS26 Microphone is a probe style unit designed for desk
or floor stand mounting. It is supplied with a Shure A57F Swivel
Adapter.
•
Low vibration and hum sensitivity
•
Frequency response tailored for voice
•
Cardioid polar pattern
•
Pop-filter grille reduces sensitivity to explosive breath sounds
•
Mounts on desk stand, floor stand or gooseneck
AMS28 Lavalier Microphone
The AMS28 microphone is designed for chest-worn operation
and is supplied with a matching lavalier assembly.
•
Low vibration and hum sensitivity
•
Frequency response tailored for voice
•
Cardioid polar pattern
•
Acoustically optimized for chest-worn operation
•
Extremely flexible long-life cable
AMS Condenser Microphones
User Guide
27B3097 (AC)
2001, Shure Incorporated
Printed in U.S.A.
