Hi George,
I am using the 4x10HD and yes the gain structure is controlled via the software, its nearly identical to your 2x4 just more of it !
When the 2245 drivers and horns are connected directly to the one amp there isn't any attenuation / filter affects from passive components
and I have a reasonable "hiss" at idle because they are 118 dB efficient .... If I can explain it that way ...
By attenuating the circuit I can reduce the idle noise and not limit the frequency response.
And, as you said adjust the gain with the DSP to suit !
I have done some basic testing of the resistor networks and with a 10 ohm in series and a 10 ohm in parallel I get about -8dB ( calculated ) at idle and now at about 2 to 3 feet back I can't hear any hiss.
Before, in a quiet room you can tell the amps are on , with the resistor networks in beautifully gone!
No issues with the amps , all 3 are 100% WOPL .
Below are the calculators I used to get started, Does it make any difference if the protection cap is before or after the resistor network..... Hmmmmm I dunno'....
M