Little bit more progress. Hardware for the adjustable slide rail installed:
Electrical hookup to speed controller next. Still working on the case holder assembly. It's more challenging than originally anticipated.
I'd say excellent mid range and highs. Bass is a bit weak but expected. Female vocals are superb. Very neutral
I would describe them as being very accurate.
I used a mixture of sand, pea gravel, pebbles from the beach by my house, crushed coloured glass. I think the speaker kit I used were the Dayton Audio RS621. Cheap but a great kit for a prototype project like this cause you just never know how it will turn out.
This summer's project will be using all hand-picked parts, even for the crossover components.
No issues at all. I think the imperfection of a raw concrete form has imperfections of symmetry and I didn't find any issues. I will intentionally use more of an asymmetric design on my next project.
Like many "luxury" watch brands, many speaker manufacturers do not make their own tweeters and woofers. The drivers I'll be using next are the exact same ones used in $15k Revels. Crossover and enclosure designs are the differentiating factor.
As for weight, they are about 40lbs each