Looking for input: Best material for mid range cone


I had a surprise last night when I switched speakers in my system.  I've got a few pairs, but had been listening mainly to some Ascend Sierra 1, which have a polypropylene cone with a soft dome tweeter in a bookshelf design.  Anyway, I've got a pair of Tannoy Precision 6.1's, and swapped them in.  

The sound was noticeably different.  Piano sounded better, vocals had a finer quality as well, and the whole sound seemed a little more lively.  Now the Tannoys have silver interior wiring, a titanium tweeter in a coax design and are only rated for 75 watts. The cone material is some kind of pressed paper fibre.  And they are voiced to somewhat push the midrange.  But the sound was compelling.

I'm just wondering about cone material because some old Paradigms with Polypropylene were really not up to snuff, but they were quite old.  Any thoughts?
213runnin
It's all very subjective. Different strokes for different folks. Cone size plays a large role as well, as does the crossover implementation.

I find that paper and plastic cones typically produce the tonal qualities that I prefer, though I've heard some metal composite cones that sound close. 

One thing I noticed is that the BBC inspired brands (all commonly regarded as having excellent midrange quality) use either some form of plastic or paper composite for their midrange drivers.
To a lot of folk, nothing beats paper (except scissors). There is, however, no one type that will suit all. It's all in the implementation. Take Vivid, for example: all aluminum drivers made in-house with carbon fibre surrounds and it's some of the finest I've heard. 

But keeping things in a financial perspective, you can't go wrong with paper or cellulose fibre cones. They have wonderful tone that smacks of an easy naturalness which accounts for that great midrange you mentioned. 

All the best,
Nonoise