A little follow-up. A few months ago I tried using a HPF and sub to deal with my low end issues. That was pretty successful below 80hz, but I still had other things I wasn't satisfied with. I bought the White EQ to work on those. But I eventually realized I could take a different approach and use the EQ to deal with all the frequency issues. Today I worked on that and essentially eliminated the need for the sub, although I'm still working on integrating it below 40hz.
My speakers are stand mounted but do have a pair of 12" woofers that put out plenty of bass. I resisted using an equalizer because of potential phase issues so went with the HPF and EQ on just the low end. But the White Instruments unit has excellent phase coherence and I'm not hearing any smearing or imaging issues. I'll continue to tweak, cause that's what I do, but I'm pretty happy with what I'm hearing.