Why do Harbeth speakers have such a cult following

There a bit of truth and a lot of BS in what you say, Audiozen. But mostly it's just an unfair misrepresentation of Harbeth and its fans.

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.

If anyone is interested, there is a thread on the Harbeth forums where designer Alan Shaw explains the origin and reasons behind the BBC thin-wall cabinet design.

http://www.harbeth.co.uk/usergroup/showthread.php?351-BBC-style-thin-wall-cabinets-Why-so-special

Simple,because they sound so good! I had many speakers over the years and these p3esr's are special. But it's all a matter of taste.

Drubin..you are way off target.." unfair misrepresentation of Harbeth and its fans?" How silly. What I described is absolutely correct and I highly praise Harbeth for the way they cut their cabinets to interact with the drivers and the sonic character they produce. I wish to hell that speaker companies would return to the more traditional design methods from the 60's that Harbeth adhere's to.
The best sounding speakers I ever heard were from that era. There is an organic rightness when the cabinets integrate with the drivers. Seductive. Castle speakers also use the same method with their cabinets and drivers. Certain KLH model's from the mid sixtie's with their electrostatic tweeter's and the driver integration with the cabinet were the best sounding speakers Henry Kloss ever designed. They were superior to his large Advents.