01-17-13: Audiozen
Harbeth designs their speakers using a method that was very common in the 1950's and 60's which was pioneered by AR, KLH and Advent. They adjust the wood cabinet to have a direct effect on the drivers to create a sonic character that some would consider colored or laid back.
Harbeth speakers trace their lineage back to the monitor designs developed by the BBC research department - for which Harbeth's founder, Dudley Harwood, worked as an engineer.
Many of the documents associated with those early BBC speaker designs are freely available on the web. You won't find any references to "adjusting the wood cabinet to have a direct effect on the drivers to create a sonic character that some would consider colored or laid back". That is complete BS you've made up.
The BBC research department assignment (for loudspeakers) was to design accurate, low coloration monitors for broadcast use. What you will find in those documents is how the speakers where evaluated with live music and voice to judge accuracy. This is something that I believe still forms the basis for Alan Shaw's current Harbeth designs.
Now I'm not saying that those early designs, nor even the current Harbeth designs, were/are completely successful (is any loudspeaker?). However it is very wrong to assert that Harbeth speakers are voiced to achieve a particular sonic coloration. They are designed primarily for accuracy and low coloration, so that the studio technician in the control room will hear an accurate representation of the sound being produced in the live studio.