Intercom volume control (7), Ntercom, Olume – PS Engineering PMA9000EX Installation Manual User Manual
Page 23: Ontrol

PS Engineering
PMA9000EX Audio Selector Panel and Intercom System
Installation and Operator’s Manual
200-920-0000
Page 3-2
Rev. 9, Jan. 2011
The system is designed to block continuous tones; therefore people humming or whistling in mon otone 
may be blocked after a few moments. 
For consistent performance, any headset microphone must be placed within ¼-inch of your lips, prefera-
bly against them. (ref: RTCA/DO-214, 1.3.1.1 (a)). 
NOTE
It is also a good idea to keep the microphone out of a direct wind path. Moving your head through a vent 
air stream may cause the IntelliVox® to open momentarily. This is normal. 
The IntelliVox® is designed to work with normal aircraft cabin noise levels (70 dB and above). It loves 
airplane noise! Therefore, it may not recognize speech and clip syllables in a quiet ca bin, such as in the 
hangar, or without the engine running. This is normal. 
For optimum microphone performance, PS Engineering recommends installation of a Microphone Muff 
Kit from Oregon Aero (1-800-888-6910). This will not only optimize VOX performance, but will improve 
the overall clarity of all your communications. 
Table 3-1 Mic Muff ™ Part Numbers
Manufacturer
Model
Mic Muff™ Part Number
Bose
Dynamic 
Electret 
M87 Dynamic 
90010 
90015 
90020 
David Clark
H10-30 
H10-20, H10-40 
H10-13.4 
90010 
90015 
90015 
Lightspeed
All
90015
Peltor
7003 
7004 
90010 
90015 
Pilot
11-20 & 11-90
90015
Sennheiser
90015
Telex
Airman 750, Echelon 
AIR3000 
90015 
90010 
3.7.2
Intercom Volume Control (7)
The smaller, inner volume control knob adjusts the loudness of the intercom 
for the pilot and copilot. It has no effect on selected radio levels, music input 
levels or passengers' volume level. 
The larger, outer volume control knob controls intercom volume or the 
passengers. It has no effect on radio or music levels. 
Adjust the radios and intercom volume for a comfortable listening level. 
Most general aviation headsets today have built-in volume controls; 
therefore, volume also can be further adjusted at the individual hea dset. 
3.7.2.1 Mono headsets in Stereo Installation
The pilot and copilot positions work with stereo or mono headsets. All passenger headsets are connected 
in parallel. Therefore, if a monaural headset is plugged in to a PMA9000EX Stereo installation, one 
channel will be shorted. Although no damage to the unit will occur, all passengers will lose one cha nnel, 
unless they switch to the “MONO” mode on the headset. PS Engineering modifies headsets to add stereo 
capability, using high-fidelity speakers. Contact factory for details. 
