Answering Dbphd, my setub is as follows:
2 subs, crossing to Open baffles containing four aluminium/magnesium midrange drivers per speaker and a ribbon tweeter (d'appolito array)
0-100Hz both subs, 48db LR crossover on subs, 60db LR crossover on mains (this gives symmetrical slopes on the filter)
100hz-3100hz 48db Linear crossover to ribbon tweeters
Calibrated, corrected, aligned, eq'd measure basically flat 16hz to 20khz in room
For most recordings this blend of crossover slopes gives a 'faultlessly' smooth performance and I never notice the slightest hint of a dip or boom in the sound, even in the bass region. Music is extremely realistic sounding, has great timing and the most dynamic response I could possibly want. Transients are simply stunning, fast, tight and deep which I guess comes from the speed of the open midrange (uncoloured by cabinets 100hz up) and the fact that all drivers only receive the optimum frequencies they are calibrated for
As the DEQX has four profiles, switchable by remote, two also use 72db LR crossovers between subs and mains with the benefit that bass is even tighter and faster when certain recordings benefit. The flip side is that this is also slightly leaner in the mid bass area of the crossover, very pleasing on a slightly muddy recording. Steeper slopes mean speakers only receive the specific frequencies specified and DEQX is smart enough to handle the time delays and phasing in the crossover seamlessly.
I tried crossovers to the ribbons with slopes from 48db all the way up to 'brick wall' 300db but the steepest required phase inversion at the crossover to avoid very slight ringing. I have settled on a 48db slope as being the most natural sounding and chose 3100hz as the point where both frequency plots were completely in phase and both driver types had similarly flat responses either side of the crossover.
I would say that achieving exactly what I wanted has taken about 5 months of continuous tweaking. I finally arrived at this back in early June and have changed nothing since. I genuinely have nothing more to change, it's as close to live music as I have heard (better than the majority because it is so clean)- I spend a lot of time at gigs and concerts.
