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CONFERENCE COMPOSER LAYOUT 
 
Most of the default parameters of the EF2280 will satisfy our design.  However, we will need to 
change the Matrix Mixer and Presets to satisfy our design goals.   
 
Matrix Mixer 
 
The matrix mixer will need to be changed from the default settings in order use Output A for the 
VSX 8000 and Output B for the Amplifier.  Inputs 1-8 need to be assigned to Output A so that the 
people on the far end of a VSX 8000 call can hear the local microphones.  The cross-points are 
colored blue to indicate that they are automixed to Output A.   
 
Inputs C and D are attenuated by 3 dB to Outputs A, B, and R1 to account for a stereo signal being 
routed to a mono output.  Since the two signals may not be correlated (i.e. have no time 
relationship between each other), then when they are added together, the summed signal will be 
+3 dB higher.   
 
In this example, we will assume that the VSX 8000, program audio, and amplifier are designed to 
send and/or receive a professional level signal.  Therefore, Inputs A, C, and D and Outputs A and 
B will be set to 0 dB.  For more information as to the reasoning behind the gain levels, please see 
the Gain Structure for Amplifiers and Other Sources page.  
Local Microphones should NEVER be included the reference signal!