We experimented with various low G trompette strings several years ago. Here's a little discussion of what we found.
The difficulty of the low trompette is the need for more mass (which we generally call weight) per length of string. The vibrating frequency of the string is a function of its length, its mass, and its tension. The length is fixed, the tension needs to be within a fairly narrow range for the trompette to function. The only parameter left to adjust is the mass. For more information about how vibrating strings work, check this Wikipedia article : http://en.wikipedia.org/wiki/Vibrating_string There are several ways of getting more mass. We can simply increase the gut string diameter, or we can add metal or something else to the string to make it heavier. Increasing the diameter is problematic. Theoretical strings have no dimension: they consist of a line that stretches from one end to the other, which is what forms all the cool harmonics when it vibrates. The larger we make the diameter of the actual string, the stiffer the string becomes and the farther the harmonics depart from their ideals. If we add metal to the string, the string mass goes up without increasing the diameter. We tried round-wound strings (smaller versions of the typical petit and gros bourdons) for the trompette, and were not pleased - they just didn't sound right. Flat-wound strings like violin/viola strings might work there, but we haven't tried them. We experimented with gimped strings, which are plain gut strings with strands of metal wound into the interior of the string to increase the mass while presenting a plain-gut exterior. The first one we tried was very nice, and I really liked it. It lasted perhaps 6 months before one of the internal wires broke. The next one only lasted about a week, and the next one about the same, and we gave up on them. They're pretty expensive, so using one a week was not reasonable. It's possible we just got a bad batch, and that others would work better. There are also a special type of gimped string where marble dust (!) is included in the mix along with the metal wire to increase the density. We haven't tried these. What I liked about the gimped strings is that they were about the same diameter as the 0.97mm we were using for C/D trompettes, while their mass was equivalent to a 1.25mm plain gut string or similar. No change in the dog was needed: string, tune, adjust, play. Your mileage may vary, of course. Alden
