I just finished my rondo-inspired Coral Beta 10 enclosures. I built them from 3 mm plywood (sides) and 15 mm plywood (front and top). Bottom is open. They sound much better than expected (to my ears at least), with impressive midrange and bass, even with my very affordable 4 watt EL84. I do seem to need some kind of equalization though (3dB boost from 125-250 Hz, and upwards tilt from 8kHz), which is not a problem in the digital domain, but is more difficult when I'm listening to vinyl. I'm curious to learn if anyone uses his Corals or similar speakers with some kind of equalization network. Next project will be to build a pair of similar enclosures for my Coral Beta 8s drivers, which i'm having restored (re-surrounded) at the moment. These drivers should at least cure the slightly dulled highs of the Beta 10s if used without eq.