Two of my favourite classical voices are those of Bryn Terfel and Jessye Norman. Over the years I have heard a number of their recordings but have generally been disappointed - as compared to what they sound like live.
Clearly there are a number of factors involved: a live performance is not just down to the sound being made and expectation must play a large part in the potential for disappointment in any given recording. That said there are other artists whose recordings I can listen to happily and not feel that too much has been lost in the process; Emma Kirkby is one who comes to mind.
So, are there voices, or indeed voice types that in general are better served, that loose less of their original character, that are perhaps simpler in their make up and are thereby less prone to the compromises made by speaker designers? As both of these singers are highly successful recording artists I can only assume that there is nothing inherently wrong with their discs, that it is purely a subjective response to what I hear.
Secondly, given that voice is so central to the development of a Harbeth speaker (and to the appraisal of any speaker) is their a distinction to be made between reproduced voices that sound natural, ie. free from the artefacts that you referred to recently
and voices that not only sound natural but also faithful to the original. Strictly speaking unless we have the original to compare to, judgement of this faithfulness is dependent on memory (flawed as it is) but we do retain a strong subjective impression of what people 'sound like' and this is obviously what I am comparing to in this instance.The real-live human voice doesn't 'do' spitty, wiry, gritty, grainy, pinched, peaky, barking, biting etc.
Of course it may well be that the speakers that I have been using were not suited to what I wanted from them!