Re: Policy, democracy and power - BBC monitors
We're off walking in the Northumbrian hills today, so I have much time to relive and add to my comments.
One thing to be aware of which has direct bearing on your comments about the presence dip on the early Harwood-designed Harbeths (HL1, Mk2 etc.) is this: Dudley Harwood, unbeknown to me at the time I took over Harbeth, was a member of a fundamentalist Christian faith. He lived a simple life, and was disinterested in the trappings of modern consumer life. He was prohibited by the rules of his group to take any interest in entertainment, and that apparently included music of any and all types. Now, you may ask how a world-renowned loudspeaker engineer could evaluate loudspeakers, unable to listen to music on them - it is difficult to comprehend what work-arounds he used. But certainly speech recordings, which were permitted, became critical to his evaluatory process. Without the formal ongoing feedback from BBC users who you mention, it must have been very difficult for Harwood, now ex-BBC and running Harbeth, to be sure about what was a correct speaker response balance bwteen bass, mid and top. If you recall, in one HFC, he was criticised for having set the tweeter level too high (Mk3?) and this was surely a direct consequence of working alone, and not listening to music and natural hearing loss with age.
However, judging, controlling and shaping the energy in the presence region (say, 1-3kHz) and the position of musical performers front-back (z-plane) is much easier in stereo, and with music. Also, again this did come up in conversation with Harwood and is in the transcript, I asked him 'what is the purpose and function of the so-called Gundry-dip where energy is reduced in the (typically) 1-2kHz region'? His answer was unequivocal .... "to mask coloration in the polypropylene cones'. This was the first admission that even though he was the father and patentee of PP cones, they had known deficiencies - quite an admission.
The BC1 had a bextrene cone, where coloration in broadly that region was ameliorated with a thick coating of PVA 'dope'.
Alan A. Shaw
Harbeth Audio UK