If I remember the LS50W have very rudimentary boundary filters, I would have set those to the appropriate setting, you can’t really expect deeper bass from the same driver in an identical volume enclosure, I thought the bass punchier from the active version and they are very versatile and easy for the whole family to enjoy.On the Active vs Passive LS50, the former also has phase correction which seems to improve the soundstage to some degree. I haven't heard the two side by side, but disabling phase correction on the active lS50W does have a noticeable effect. The instruments and voices just seems more focused with that feature enabled.
There's also the matter of bass. It was interesting that @Purité Audio 's measurements showed pretty much no difference, even though KEF's specs suggest otherwise.
According to KEF, the LS50 is - 3dB at 79hz while the LS50W is -3dB at 50hz with the default settings. The -6dB point is not as wide a gap at 47hz for the LS50 and and 43 for the LS50W, but that can be extended to 40hz.
I assume you were using the default DSP settings, Keith?
Keith