I'm trying to start a project. I want to create something between a baritone horn and a bass trombone. The need for this is that the physical requirements of the bass trombone are wearing on me, and I need something easier to hold and play. A tuba seems too much. F cimbasso might be close, but its so ungainly. So it has to have the range of a bass trombone, but the sound can be a little darker than a normal bass bone, so something in the baritone range, but probably not as dark as a euphonium. If that makes any sense.
I'm not sure where to start sourcing parts, but I'm thinking a large bore non-compensating piston valve set. Maybe a 5th rotary valve. Large shank (bass trombone mouthpiece) leadpipe. A 10-11" forward facing bell. Not sure if it should be in Bb or F. It would need a range of F an octave below the bass clef to F an octave above the bass clef, with an emphasis on playability in the lower notes. I guess I'm looking for something with a large bore, but not sure where to look. What would be a large bore euphonium model with 4 non-compensating valves that I could economically scrap for parts?
I started to think this was sounding a lot like a double wagner tuba, but I'm not sure I understand what that is or how it's pitched. Saying "it's the same as a french horn" isn't really helpful, since I don't understand that either. For example I know F and Bb, but is F above Bb or the other way around? Is the Bb trumpet Bb or trombone Bb? and the F is like F tuba or something else?
Am I just describing a Wessex Bubbie 5? or is that really just a useless novelty? Is it more a bass baritone than an F tuba?