proac sound vs coincident sound

Is ProAc cold and analytical? Does it require tubes to be listenable?

Kind of. Definitely tilted that way, of course, it is all a matter of taste. Jack Sprat could eat no fat while his wife could eat no lean. Are Proac speakers "unlistenable" ? - if you are like his wife then yes.

Very interesting. I've had the impression from the forums that Proacs in general
were in the British Harbeth school--"forgiving," which
I thought meant not too icy or piercing.
I guess this British sound is confined to, say,
Wilson Benesch, Spendor, maybe Tyler from what I've
read on the 'gon. At least that's my impression from
my reading here. Thanks.

I've heard the 2.5's on Plinius gear.
Not bright, not cold.
Nice warm midrange
A bit rolled-off on top.
A bit thick and slow down low.
I liked them but not enough to buy them - I got Reynaud's instead.
That's what I heard.

Read the Stereophile review carefully, and you'll see that the D28s are significantly different from the Response 2.5s--not only the new advanced porting system, but different drivers from different manufacturers. Haven't heard the D28s, but the older speakers are much closer to the, for sake of a better word, "English" school.

The ProAcs are definitely not cold or bright, quite the opposite, especially when matched with tubes. I almost bought a pair of Studio 140's myself - nice sounding speakers. Not familiar with the Coincident speakers, so can't comment there.