3ft= 200ms or 500ms delay
U get Bleeding and time delay arrivals from different mic distances and how far away they are u know
i just thought about using mic polarity adapters to change the phase/polarity of the mics this might help out some also but we are mixing down to MONO signal channel
I was thinking also about that linear phase filter it might ALIGN the time delays from all the mics in the room up its about ALIGNING because they are all NUGDED alittle in microseconds or milliseconds creating a slap back delays or offset delays so maybe running the whole band to a multiband linear phase filter will ALIGN it up more for MONO?