Arke "Vader" CNO4's - Hello There

I know I referenced some recordings potentially sounding a little "shrill/over-egged" (attributing this to the recording/mastering) but the CNO4's seem to have the ability to tame some of these, at least a lot better than some other speakers I have heard (not done direct comparison with Ekta's etc though).

The tweeter size/quality may also have a lot to do with this, as Jason suggests. 

Bad parts on recordings can remain bad, but somehow, less bad, if that makes sense. The CNO4's ability to unravel midrange complexities though, that is something quite spectacular. There are notes within notes that they are able to separate which just brings a smile to the face.

Putting aside the drivers used and their technical features, when I examine the measurement graphs of Revelator-851, Cno-4 and Nextel-2F, there is a drop curve after 15khz in the high frequency band of Cno-4 and Nextel-2f. There is a peak between 15-18khz in Revelator-851. Could this drop in the 29mm driver be softening the end sound?

I've owned speakers where the tweeters probably cost 50p bought in bulk but you could still practically hear the rivets on the cymbals.

More expensive tweeters can have the advantage of wider dispersion, higher power handling and perhaps can be crossed lower but any driver of any type and price will sound good used within its limitations.

Better drivers give more flexibility in the design but they don't have mystical qualities beyond what is in their performance specs.

Particularly, the idea that drivers have inherent qualities based on the material they are made of should be dismissed. For example, metal dome tweeters generally have better power handling but won't sound different to another type just because they are metal based. They are still just pushing air movements to the ears and air movement cannot contain different 'qualities'.

Problems with tweeters being harsh or shrill are due to incompetent design, trying to cross them over too low, nothing to do with metal vs other materials.

Yes this is precisely my point - it's a myth that metal drivers 'sound metallic' or that paper drivers sound 'papery'. How they perform is entirely quantifiable.