This is part of the story of my reconstructed Weltklang baritone. Since it could be of some general interest, it is given here in full.
A wind instrument essentially is made out of air. The tube is just a container, a container defining the shape of the air column. There are several claims on the type of material of this container in connection to its sonority. Among others from Jim Schmidt in mouthpieces and from Karsten Gloger in necks. Very interesting and well-founded experiments were executed by Dave Monette and Jason Harrelson with trumpets. Following them I put things to the test in a saxophone. An answer?
Adolphe Sax distanced himself fiercely from wall material influencing sonority: it is all about the form of the air column. This was nicely illustrated by the wooden trumpet of Mahillion and Sax's own metal clarinet. But in the experiments of Harrelson something else is at stake than solely the use of wood or brass, copper and silver. The trumpet builder introduces the term 'standing wave efficiency', meaning as much as that the wave should lose as little energy as possible in making the walls of the instrument vibrate. The walls of a metal wind instrument do vibrate and this vibration can only be caused by taking energy from the movement of the air within. Harrelson considers this vibrating-along to be a waste and he dampens it by making his trumpets thick-walled and he fortifies them with extra bracings and bridges. Eric Veldkamp in Sonic 4.2006 reviews these instruments rather positively, writing about a quick response and a compact and well-centered sound.
I once saw pictures on the internet of a tenor saxophone's neck wrapped in elastic band. Some of Jim Schmidt's saxophones had metal rings soldered around the neck. In 2003 he wrote on his website: "The 'power rings' that you see in the images add weight (...) and serve to further enrich the fat husky tone." Without explaining too much about backgrounds, with Karsten Gloger also you find an indication of the use of extra mass. He speaks of the use of 'high density' brass or silver. A higher density can be obtained by hammering the metal. Gloger is, notwithstanding the many pictures on his website, not that clear about his procedures nor about the wall thickness he uses. Stephen Howard reviews Glogers necks positively, writing: "My initial impression was 'more of everything'. It was appreciably freer blowing, and if I had to put a figure on it I'd say that punch and clarity were up a good 20-30%." For the rest the drift of the reviews of Eric Veldkamp and Stephen Howard is rather similar, as much as their objects differ. That makes curious, isn't it?
The crook of my Weltklang baritone is rather thin-walled, the brass measuring only 0.5 millimetre. It is without a trace of doubt that this crook (and the upper bow) vibrate along when playing the instrument. An ideal stretch to examine the influence of added mass. For the sake of experiment, the crook and the upper bow were covered with a little over half a kilogram of clay, an easily usable, heavy and acoustically perfectly dead material. This combination of properties was deliberately looked for, since, following Harrelson, the damping of vibration of the instrument's wall was the prime goal. After this treatment no more vibrations were felt with the fingertips in the uncovered parts of the bows (later on the neck was partially covered with clay as well – not in this picture).
A first impression surely was convincing: indeed sonority had changed! It is difficult though to say in what way exactly, because the sound in some way remained just the same, but you had the impression that there was more of it. Not necessarily more volume, but more resonance, more punch, a more ringing sound. A quicker response and along with that maybe a somewhat exacter response. This property seems to be consistent with what Eric Veldkamp describes as a better 'slotting' of the trumpet's tone. Also it seemed as if, putting it very cautiously, sonority was more even: where previously a F1 would sound a bit different from a E1 and especially a D1 from a C1 this difference to its advantage had got smaller.
By and large that's again the same impression that Eric Veldkamp and Stephen Howard try to describe. The tendency is clear: the energy loss that a vibrating wall produces must be prevented. In matters of damping, probably the same holds true as in intonation, namely that the upper part of the instrument is of prime importance because a full octave of pressure antinodes is located here.
|Clay of course cannot be used as a permanent material. Though fit for an experiment, something else had to be looked for. The next step was made by attaching lead rings to the crook and upper bow. These were placed at the pressure antinodes and attached to the instrument by a thick double-sided adhesive tape.
The effect on sonority with the lead rings clearly is similar to that of the clay. It remains yet hard to compare both states correctly. Nonetheless, judging by a couple of known difficulties, such as downward intervals of more than an octave, the difference in sonority between D2 and D1 (which tends to be small, indicating that there is a rather strong second partial in the D1) and the evenness in sonority in the bottom end of the first register, the final judgement still is a positive one.
|For a couple of years the lead rings have been a part of the instrument, but were then replaced by a thick glue-lined heat shrink tube.
Of course, it all got a lot less heavy. More importantly, this solution works even better than the one with the lead rings. However, it must be noted that this construction is possible in its perfection only because in this baritone the crook is just a bare piece of tubing having no extra bracings. And of course, as said, the crook of the Weltklang is quite thin-walled. This might mean that the gain in additional damping yielded is probably larger than it would be in another instrument.
|Eventually the entire body of the baritone was wrapped up in rubber, subtly enhancing the described effects once more: reponse in the low range is faster, more playful I'd almost say and a difference in sonority in the octave D1 / D2 is clearly more pronounced than it was.
The open-key tenor saxophone was treated in the same way, yielding similar results, though less pronounced than in the baritone. A slightly quicker and more exact response in the low range now being the most prominent effect.