The reason the Knight templar posted this was we feel that underslung , not under over as in 20s and yani, but toally underslung is a very good design.Ok the mechanism you could argue is a little tricky, but we favour its look and its gravitational pull , ha, ha.We have a 10m underlung, one before they put those guards on the bell , so its 1round 1959, 63ish This actually is in our view one of the best.Amazingly this one is not rolled.This one we mention here creates a fraction more cut and lift, its very slight.The older ones may just have it ,but we found the crook sleeve on this 10m made like the 6ms is a factor in producing more power than any horn we have ever had,now as you people have pointed out its unlikely to be the underslung octive, or does it make a conttribution? because you can set it wide open this way round and is as quick to respond back onto G. Is this vent hole different from say selmer, in that fullness, stuffy sound, bright , or full, can it be adusted by the design and size of opening? (Bird Lives)