I'll have a finished picture soon. In the process (actually grandma is) of sewing covers for the tube.
I'm cutting them to length, drilling a hole in the end, adding some strategically place rubber, and putting on a cover.
I messed around with a dozen different designs (hole sizes, porting with rubber gromets, inverted tubes, different lengths, different brands of bats, etc...) as well as field testing them the last few years. This is the BEST sounding combo I could come up with. I will be taking this tube to the RMEF elk calling championships in Vegas.
The backpressure in this tube is awesome and makes it easier to run the diaphragms as well as the added resonance on the low notes.