Hi Troels,
I've been enjoying my CNO4 speakers for a few weeks now, but not before sorting out a few issues. To begin with, I think these SEAS drivers, which are fantastic, need a lot of break-in and you have to be patient.
I also added a rear ribbon tweeter and two Fostex attenuators for the front and rear tweeters. I used the lowest resistor setting, and with the attenuator, I achieved the most appropriate treble level, just the way I like it. I think it was a good idea, and I encourage future builders to implement it.
The rear tweeter offers more air and with the attenuator I can mute it if I want.

As for the 12" driver, after consulting with you, I installed the Faital 12-430, which sounds fantastic.

The internal wiring is from Duelund, and the cabinets are made of 25mm MDF. The lacquer color matches the wall colour so they integrated better with the room.

After three months of listening, I can now say that they sound incredible: extremely smooth yet detailed, with a deep bass that can be adjusted to suit any room.

Congratulations on this fantastic design and thank you so much for your help.

Best regards, Javier