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. The top of the knurled knob contains reference marks every 45o; these may be used to position the microphones at the desired angle (see Figure 1).
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 coincident or closely spaced mounting with a wide range of directional 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 microphone cables is included.
FIGURE 1 6. Tighten the knurled knob, attach the microphone cables, and use the supplied cable clamp to fasten the microphone cables to the A27M. 7. Raise the microphone stand to the desired height. Figure 2 shows a pair of Shure SM81 microphones mounted in an �ORTF� configuration on the A27M.
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.
