User Manual

ManualsBrandsShure ManualsMic Stands, Mounts & AccessoriesStereo Stand Adapter for Pair of Microphones

Model A27M User Guide

27B1424 (Rev. 3)

Printed in U.S.A.

STEREO MICROPHONE ADAPTER

The Shure model A27M is a stereo microphone adapter

designed to hold two microphones in selectable positions for

stereo broadcasting, recording or sound reinforcement. It

allows two microphones to share one stand without losing

independent positioning flexibility. The A27M permits coin-

cident or closely spaced mounting with a wide range of di-

rectional angles, and vertical microphone separations of 1

1/4 inches (31.8 mm), 2 5/8 inches (66.7 mm) or 4 inches

(102 mm).

The A27M consists of two vertically stacked sections that

rotate on their centers. Each contains a 5/8"-27 threaded

stud and locking ring to accept a variety of microphones.

The bottom section contains a 5/8"-27 adapter for mounting

on a microphone stand. A cable clamp for holding micro-

phone cables is included.

Installation

To install the A27M, follow these steps:

1. Determine the vertical separation between microphones

you desire. Minimum separation (coincident spacing) is

generally desirable, but it may be necessary to provide

greater spacing to accommodate the size or style of the

microphones. By repositioning the sections of the

A27M, the threaded studs may be 1 1/4 inches (31.8

mm), 2 5/8 inches (66.7 mm) or 4 inches (102 mm)

apart.

2. To reposition the sections, unscrew the knurled knob at

the top of the A27M and slide the two black sections off

the vertical rod. Reposition the sections with the studs

positioned for the vertical spacing desired. Replace the

knurled knob.

3. Attach the microphones or swivel adapters (such as the

Shure A57D or A57E) to the 5/8"-27 studs.

4. Attach the A27M to a microphone stand with a 5/8"-27

mounting thread.

5. Insert the microphones in the swivel adapters, loosen

the knurled knob on the top of the A27M, and position

the microphones for the desired response angles. The

top of the knurled knob contains reference marks every

; these may be used to position the microphones at

the desired angle (see Figure 1).

FIGURE 1

6. Tighten the knurled knob, attach the microphone cables,

and use the supplied cable clamp to fasten the micro-

phone cables to the A27M.

7. Raise the microphone stand to the desired height. Fig-

ure 2 shows a pair of Shure SM81 microphones

mounted in an “ORTF” configuration on the A27M.

FIGURE 2

Summary of content (2 pages)

PAGE 1
Model A27M User Guide STEREO MICROPHONE ADAPTER 3. Attach the microphones or swivel adapters (such as the Shure A57D or A57E) to the 5/8"-27 studs. 4. Attach the A27M to a microphone stand with a 5/8"-27 mounting thread. 5. Insert the microphones in the swivel adapters, loosen the knurled knob on the top of the A27M, and position the microphones for the desired response angles.
PAGE 2
Stereo Recording Options The A27M supports various popular pickup systems. Those described below result in (1) improved imaging over widely spaced microphones, and (2) superior depth reproduction over individually miked instruments. The spaced microphone technique creates a stereo effect mainly because of differences in the arrival time of the sound at each microphone. Coincident systems produce minimal arrival time differences. The stereo effect they create is due to interchannel amplitude differences.