@simonmoon, Hi Simon I read with mounting interest that you owned Bagby's Kairos speakers. I design and build speakers and have a friend who asked me to help with assembling the XOs for his pair of Kairos. The components were reasonable quality budget units and the resulting sound I thought excellent and feel they would respond to better quality. After owning them for 4 years he wanted to upgrade. It' a long story with me now living in a different country and unable to help so he's looking at another kit.
Have you heard the "Bordeaux" speakers that you are building? If I may ask, what would these cost, what lead you to these and in what way are they better? I suggested my friend upgrade the XOs, seal the ports and augment with subs but the nagging suspicion there's something better out there raises it's ugly head.
It's a disease