Update: I had Ossi Percussion in Finland make me an 18” djembe, lug-tuned, elm wood, goat skin head. As expected, it pretty much shakes the house on the low notes. It’s interesting to note than you pretty much have to muffle with your other hand on every note, though. The drum is too resonant to just play without some kind of hand muffling.
It’s exactly what I needed for playing with my church choir. A regular 14” djembe is still too high-pitched for playing with a church choir. Most choirs can’t sing loud enough, and even a 14” djembe covers up their sound.
I do miss the tight sound of a normal djembe, though. But this thing can really do an awesome backbeat, because the bass tone on it is as low as a kick drum.