These program act like a bass drop.(a sweeping sine wave) I mean with lowering the input the Peak and notches start going toward the low end until they become flat in -9 dB (DNM SEL)
I was thinking that this is what real console do with the response dependent on the Input volume, but now I am a little consernd, since many nebula programs(Consoles,Mojos,Dynamic EE/Filters...) act like this
have you tried the programs with actual music materials?
when you say it goes away with -9db of input level, then no peak (on specific narrow frequency ranges) will ever reach that level with musical material. it is really deceiving to look at the full frequency plot.
you could try to mimic single musical tones with sinuses on specific frequencies (with appropriate levels), to get a impression, what a program really does in that frequencyrange.
system 1: windows 8 32 bit - samplitude prox/x3, tracktion6/7, reaper system 2: mac osx yosemite - reaper(32+64bit), tracktion6/7(32+64bit)
both systems on: macbook pro (late 2009), core 2 duo 3,06 ghz, 4 gb ram, graphic: nvidia geforce 9600M GT 512 MB