The C1 was in my list of speakers when I was looking a few years ago.
Tremendous speaker. What would you like to know?
The biggest negative was the price. But other than that it's a phenomenal speaker.
If you have the amp to drive it will absolutely kill many floorstanders with ease.
Superb mids and low end that will satisfy most musical tastes - highs are clean as a whistle.
This is a speaker ideal for smaller (living) rooms - will not overload the room.
With an amp that has plenty of headroom this speaker will make the room sing.
If your source has the quality, the C1 has the resolution for you to hear it.
I have not heard the C20.
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