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https://www.kartesian-acoustic.com/products
These drivers appear to be held to high standards. The Klippel measurements of their small midbasses is SOTA, and well performing.
Check out this 4":
https://www.kartesian-acoustic.com/copie-de-sub120-vhp-2
Comments
This looks nice
https://www.kartesian-acoustic.com/copie-de-wom165-vhe
We might be able to group buy samples, but from how it looks they generally are not too interested in DIY.
Take a look at the AMT. It looks really familiar, ahem (AMT1-4) cough...
InDIYana Event Website
4", 82.5dB, 5.5mm xmax, CAD$100+, I'll pass, looks aimed at the soundbar market. They might have some nice drivers, but cost at low qty is high especially considering shipping cost from France.