Bose FreeSpace E4 Series II Owner's Manual page 16

The following are examples of correct and incorrect sensing
microphone placements:
Correct placement
Correct placement
Installer's Note: In applications where ceiling height is less
than 12 feet (3.6 m), the microphone should be wall mounted.
2.0 Designing with the E4 System
Sensing
microphone
Sensing
microphone
Ceiling Flush
Wall Surface
16 of 80
Incorrect placement
Sensing
microphone
Incorrect placement
Sensing
microphone
Mic