>>"Anyone out there with advice/solutions to achieving perfect balance of low frequency that does not requre constant adjustment?"<<
Try setting your sub's crossover 1 octive above your speakers -3db point, and use the subs volume control for blending.
If your speakers are full range, and lets say their -3db point is 25hz, set the sub crossover at 50hz, if you are using a mini monitors whose -3db point is lets say 40hz, then set the crossover on the sub at 80hz.
Now all you have to deal with is the standing waves, and bloat from the rooms Primary Resonate Frequency points.
Try setting your sub's crossover 1 octive above your speakers -3db point, and use the subs volume control for blending.
If your speakers are full range, and lets say their -3db point is 25hz, set the sub crossover at 50hz, if you are using a mini monitors whose -3db point is lets say 40hz, then set the crossover on the sub at 80hz.
Now all you have to deal with is the standing waves, and bloat from the rooms Primary Resonate Frequency points.