Not sure I understand what you mean P.H. Are you pointing to an overall lack of acceleration across the mid frequency range of 250 to 6k Hz, due to too much mass and too weak a flux field? Or do you mean that the acceleration at higher frequencies doesn't match that of lower frequencies, with a break point at the all important 800Hz, the point at which a large diameter driver ceases to move in a minimum phase manner?No Lowther driver has a voice coil that is suitable for proper midrange and above midrange reproduction. Everything above 0,18-0,20 grams (including the weight of the former material) is not suitable. If it weights more - you will always feel/hear that gravity problem to some extent, of course depending on how high your reference points are.
I do not have an argument with your statement, just trying to see how it applies to what I am finding. I deliberately chose 300Hz as the Eminence to Lowther crossover to free the Lowther from coloration's due to extensive non minimum phase movement from the rather light weight cone construction, knowing full well that passive crossovers do not "turn off" a driver, just turn it down by -60 dB or so.
rowuk I have been dealing with that "topple" problem by moving the slant in tweeter back from flush mounted to a position that causes orchestral "height" to assume a natural position,. What you might expect from 20th row seating in a proper concert hall. I am uninterested in reproducing the spl and dynamics of live sound, as it was recorded at the microphone or closer, preferring a healthy distance in the subjective sound field illusion. So I am very interested in the perceived phase, from a vertical phantom emitter, that places each instrument properly and keeps all of the frequencies involved in that instruments expression time aligned. Having the EnABL process on all drivers does aid in this as I have coherent information off of the drivers, to around -90db from signal level. Obviously not all of those tiny signals are individually audible, but the massive over sample and pick and choose filtering of our involved sensory systems, does allow a useful understanding to arise over a time period.
As for my level of discrimination, which I assume means reference points being high enough, I have no way to express this. If you can find a local audio friend who has invested in a pair of Dave Dlugos's Planet 10 Hi Fi full range driver Fostex based monitors, please beg a listen. That will tell you more than any amount of verbiage or arm waving I might present here.