KEF Concerto improved DN12 crossover with full aB circuit

Before you try a new crossover, decide whether the problem is voicing (tone) or blending (the actual cross). This is important knowing the way forward to give you peace of mind.

Do this by trying to EQ the speaker. If you can fix the issue, it is a voicing problem and you should hold the relative driver contributions the same when you make changes.

If you are unable to fix the problem with EQ, it is a blending issue. The relative contribution of the drivers needs to be changed. This comes down to phase, overlap and also about issues that only one driver suffers from. After that, repeat the EQ test.
 
I recently acquired a pair of KEF kit Cantatas that I am trying to upgrade to sound more like Concertos, albeit in an infinite baffle (i.e. sealed enclosure) configuration. In order to do so I have replaced all the capacitors in the original crossovers, replacing the dialectrics in the woofer and midrange circuits with new upgraded dialectrics (Solens) and in the tweeter circuit with polypropylene Audyn Q4s. I have also replaced the original iron core coil in the tweeter section with an air core. I have retained the original Cantata crossover configuration (attached) for the mid and bass as I assume it is best suited to the sealed enclosure, but have altered the high end to acccommodate T27s as were featured in the original Concertos. Instead of paying for the now even more expensive (for those of us benighted souls in the U.S.) Falcon T27s, I have followed their advice and substituted Morel CAP 298s. This leaves me with two questions.
1. Do I need to modify the Concerto crossover (I am using a modified design by eschenborn posted 21-04-09 in this thread for the tweeter section, attached) to accommodate the Morel CAP 298? If so, how? Another diyAudio thread "2 Concertos are dead now..." deals with this issue to the extent that Eric Stockman posted on 21-09-09 that Falcon stated that their upgraded Concerto crossover "won't work effectively with the Morel as the aB HF section is specific to the T27". Sytem 7 posted a crossover design in response to this (attached), but it used the KEF B200 rather than the 110.
2. Some suggest that I will need to attenuate the input to the tweeter section by adding a resistor Eschenborn KEF Concerto_crossover modifications.jpgSystem7 KEF-104ab.JPG because of the lower ESR of the flim caps that I have substituted for the electrolytics. Is this necessary? There seems to be some disagreement about this.
My apologies for the lengthy query.
 

Attachments