When would you ever run aux fed subs pre fade? Lets say LR bus feeds mains, Mix1 feeds subs, and kick on CH1. All channels feeding Mix1 are post fade.
The main CH1 channel fader would increase/decrease overall volume of the kick, and the CH1/Mix1 crosspoint would then become your blend, where 0dB would send an equal level of signal to mains and subs, and the +10dB headroom allows you to feed more to the subs than mains.
The only use case i can think of for pre fade aux fed subs would be when you want to send significantly more signal to subs than mains, or to subs only, which would suggest your gain structure is wrong coming out the desk. I don’t understand when you would ever want independent control of sends to mains/subs?
