It's funny, this audio thing. Now that you have explained it, I really am looking for entirely impractical ways to apply the principle of using tubes. Have you heard of a material called Ardex? It's basically a plasicised PVC that shapes, carves, trowells - whatever - like buttah! Oh yeah, it's solid like concrete when it cures. Such a beautiful material. I get it at HD Supply/White Cap. Anyway, thinking of cardbord tubing up then spraying ardex on like stucco. Could be a hideously beautiful thing. Send me some drwings of your Athenian Array !