I was wondering if anybody has build a sonotube with a shiva and the 15" passive radiator from adire. I was thinking about possibly making one and having the PR top firing. I'm not sure about what size yet, but maybe around 4-5 ft^3 which with an 18" tube would be aorund 28-35 inches tall. I would probably use a PE plate amp with 250 watts. Would there be any advantages to using a PR our would I be better of just porting the tube.