Why does Mark talk as if he invented the spider less driver? It’s been done multiple times before. One chap in the Netherlands got rid of not just the spider but also the primary suspension, the rubber surround.
No real need for high QTS, these drivers work fine open baffle just don't expect loads of bass, even if they were high QTS they would need supplementing with some sort of woofer. I might well be working on open baffle kits doing just this......