Posted by Rick Denney on July 01, 2000 at 15:56:14:
In Reply to: Re: Re: Re: Re: 4/4, 5/4, Monster! posted by John Swensen on June 30, 2000 at 12:45:25:
It would not be that hard. All you'd have to do is measure the diameter of the tubing at places where the taper changes, starting at the mouthpiece and going straight through the open bugle. Differences in the valves would be swallowed up by the volume of the bell, which dwarfs the rest of the instrument--but then, this is a measure mostly o fthe size of the outer branches. Calculate the area at one change, the area at the next change, and the length in between. Add the two areas, divide by 2, and multiply by the length--that will give you the volume of that section of the horn. Add up each section. The manufacturers have the taper designs already figure out--it would be easy for them.
The bell is the only place where the arithmetic is troublesome for those who took naps during analytical geometry class. But the manufacturer could fill just the bell with water, and calculate the rest of the instrument if they don't want to crunch the numbers.
Unlike most descriptions used in marketing a horn, the volume is a fact and not subjective hype. It probably has some usefulness. I would personally rather know that value than either bore or bell diameter. Those numbers are always provided, because they are currently the only two actual measurable parameters that people can use to compare instruments.
For example, it would be valuable to know whether a VMI 3301 had more or less volume than a Willson BBb, especially if that could be compared with other instruments made in the past (say, for example, a York Master). The pictures in the catalogs and web pages don't show the scale, so it's hard to tell whether one instrument is really bigger or smaller than another one, unless the difference is huge (like, say, an HB-50 vs. an HB-21).
Would it be a replacement for play-testing and listening to the instrument? Of course not. But think of all the threads on Tubenet that could be filled with arguments about those numbers. "My SIX-quarter PT-7, with it's 58.4-liter volume is obviously better than your FIVE-quarter Willson, with it's paltry 58.2-liter volume!" "Oh, yeah?..."
Rick "Bore size is boring" Denney