He actually studied Business, but was making speakers for himself since young.I now this story by heart. Alan Shaw IS Harbeth and the hole story is part of his unique selling point. But I still can't believe, that a graduated engineer like him doesn't make use of all the software out there which helps manufacturers like the before mentioned Neumann and Genelec (or Revel, Kef etc...) to develop SOTA speakers right to taste (Harman curve!) in reasonable time.
It just fits too perfect in the cliché of a small high end manufacturer. If he would be able to reach his goal ("perfect replication of his daughters voice") in much shorter time by using modern development tools: don't you think he will use them? Or actually does in order to get the job done without spending months unwinding coils?
He develops his crossovers in a simulator on a PC like everyone else. His body of knowledge predates Harman---he has read all the BBC papers. And continues to read all the new publications.
He would rent the BBC anechoic chamber to measure his speakers. Until it was decommissioned. He would hoist his speakers on a long pole outdoors and measure them.
Yet, he still spends a long time voicing each speaker by ear.