This thread concerns the basic technical reason that a Harbeth sounds so much more open and fresher, with more micro-detail than other speakers. The original post was elsewhere on the User Group, but as this is such an important subject, I've decided to move the subject here.
I said this in response to a prospective customer who complained that he was was not hearing enough detail with his existing speakers, the cones of which are advertised as being vacuum formed from a general-purpose plastic of the sort used to make squeezy cosmetic bottles.
My comments were:
The reason you have a dead, lifeless, airless lacklustre sound is very simple and has nothing to do with your amplifier. What you are hearing is the sonic signature of vacuum formed homopolymer polypropylene as used in the bass/mid cone.Originally Posted by midwoofer
Nothing - I repeat - nothing - inside the speaker system, outside in the electronics, the room or even the music can restore what V.F.H. polypropylene robs from the micro-detail in the music. Once music has passed through V.F.H. polypropylene cones on its way to your ears as sound, something will have been removed from the music. In fact, as you may know from our Govt. funded cone research project, what actually happens is that the low-level sonic detail* is converted to heat inside the cone (due to friction in the V.F.H.polypropylene molecules) and there is no return path from friction back to sound. Once the sound has gone, it's gone. The process is exactly akin to recording the finest digital recording onto cassette tape; the detail is lost below the granular noise of the tape particles and merges into the background noise as a continuous mush. This seems to be a serious problem in V.F.H.P 8" 200mm driver cones: the missing detail can never be restored and what's left is certainly smooth - but foggy.
The reason only a Harbeth sounds like a Harbeth (that is, it has incredible detail) is because of our RADIAL cone material. Simple as that really! You could spend years chasing this speaker or that and wasting much time and money in pursuit of the resolution you are missing. Please don't waste your time and money. You can't out-Harbeth a Harbeth by using yesterdays speaker technology.
* The best examples of this fogging process at work -
a) listen to a clean recording of a soprano in a large hall on V.F.H.P. cones and observe how, in the gaps between phrases as her voice decays into the acoustic space, it is as if the walls concert hall walls are covered in cotton wool. The micro detail, just above the recording's noise floor has been rubbed out. You can not really determine how large the hall is because the reverberation tail behind the voice has been corrupted.
b) listen to brass instruments on V.F.H.P cones - it is not capable of resolving the complex harmonic 'rasp' of brass, which in real life, and on Harbeth's RADIAL cone, has the correct 'bite'. Yes, V.F.H.P. is definitely smooth but has the sonic corners rounded off; it acts like an acoustic filter.