TubeNet

Commercially available airhorn drivers do not work on tuba, I've tried them. They can squeak and play some ugly wolf tones, but the diaphragm is too stiff for low notes. One could probably construct an airhorn driver that fits in a tuba mouthpiece receiver, but it won't be much louder than blowing the tuba. The limit is the air velocity in the small part of the horn, which is basically the same in tubas, trumpets, and ship horns. Ship horns get their power from the large throat diameter. Technically, they are extremely inefficient compared to brass instruments, and waste most of the energy in the high pressure air they are fed.

What I've been thinking of doing is sacrificing a poor playing tuba by cutting it where the tubing is larger in diameter and fabricating a low pressure air horn driver for it. The driver is nothing more than a circular chamber surrounding the end of the horn pipe with a diaphragm that attaches to the rim and stretches across the end of the horn pipe. A driver made from a plastic bell reducer fitting and a small drum head diaphragm would probably work. I have a beautiful looking but terrible playing King Eb sousaphone that might end up as a horn for my RV bus.

-Eric

I don't know of any reed horns other than in pipe organs, but I'm sure a pipe organ style reed could be made to produce sound on a tuba just like a tenor sax mouthpiece does. Most ships have abandoned the extremely inefficient airhorns (steam horns originally) for much more efficient piston horns. The advantage of a diaphragm style air horn driver, though, is that it is extremely simple. I made one from a 5 gallon pail that produced a low tone from a length of 4" pvc pipe. Yogurt cups, film canisters, and tupperware can be made into air horn drivers too. I've moved on to servo controlled musical sirens, but I regret never making a ultra low air horn from a tuba.

A friend of mine made an experimental avalanche-causer to safely remove the threat of avalanches from a distance as a variation of piston horn. He removed the cylinder head from an old lawnmower engine and replaced it with a plate that bolted to the end of 20 feet of 18" sewer pipe. An electric motor spun the engine crankshaft at just the right speed to produce a resonance in the pipe, and the sound waves were powerful enough to cause an avalanche at a distance. Another inventor made a gun that shot quarter sticks of dynamite and did a much more precise job so the acoustic device never found a market. Maybe you could make a piston horn similarly, using a model airplane engine or a small air compressor?



-Eric

I think there is something like that ship horn that is sounded when a goal is made by the San Jose Sharks professional hockey team. It sort of sets up a sharks/salt water/oceanic ambience in the arena. The San Francisco Bay area loves its sharks.

goodgigs wrote:Ace,
I've bin in the shark tank and NO that's not a ship horn. Peoples ears would bleed it it were.

Brian,

It sounds something like a ship horn. Do you know what it is they use there at the tank?

Ace

All NHL teams have a goal horn similar to that:
http://www.youtube.com/watch?v=n__TmA3YHh4

I would rather play my tuba and mic it through my 6, 300 watt J.B.L. EON loudspeakers.