a straighter CONE

Two days before the expiring of the first patent, on the 19th of april 1866 Sax was granted his second patent.

In the years that had passed his instruments had turned out to be a very welcome addition, especially in military bands, but several shortcomings had meanwhile also become undeniable. In his second patent Sax anticipates possible solutions to the problems and at he same time tries to put a spoke in the wheel of his competitors. He claims in this patent (apart from some very interesting, yet never accepted additions and alterations to the mechanism) various other variants of the cone beside the parabolic one. Among other things the patent poses:

VI. A sixth perfection concerns the bore of the instrument. As much as uptil now I gave the bore of the saxophone a form which approaches a parabolic cone, I now reserve two new dispositions of the cone, the one a straight cone and the other a contracted or concave cone, being the opposite of the parabolic cone.

Obviously, in Sax's eyes the parabolic cone is not an essential feature to the saxophone, because here he also claims the opposite form and even as an improvement (!). But for now, it is primarily of interest that here he makes a statement on what he meant with the parabolic cone: it is the opposite of a contracted cone, so it is a cone that bulges out, that is wider than what you might expect on the basis of entrance and end sizes, such as we have indeed found in the original bore profiles. We wonder whether this passage in the patent is only there because of strategic or juridical reasons or if Sax indeed changed the design of his instruments. To obtain an answer to this question, another quartet of instruments from the period of the second patent is measured. These instruments were compared to the first set of measurements. From top to bottom the first and the second set:

  • soprano saxophone 19575 in Bb from 1859
  • alto saxophone 24495 in Eb from 1861
  • tenor saxophone 15676 in Bb from 1856
  • baritone saxophone 22500 in Eb from 1860

  • soprano saxophone 41322 in Bb from 1884
  • alto saxophone 31512 in Eb from 1872
  • tenor saxophone 30637 in Bb from 1865
  • baritone saxophone 41197 in Eb from 1882

profiles of two quartets of instruments by Adolphe Sax sr. show profiles

Other than on the previous page, these profiles were all drawn on 1:10 scales, clearly showing the differences in conicity between the various instrument sizes. Only the zeros are given as the scales differ greatly in size among one another. When we contemplate the profiles of these two generations of instruments, there is a number of interesting things to be noticed:

An interesting specimen in the history of the bore profile is alto saxophone 10543 in F from 1854 (not documented here) since it combines traits of the pre-1866 instruments, like the wide bell, with those of the post-1866 ones. Other than the F-mezzo prototype AIS-341, which, despite its incomplete state, is still clearly a fine example of the parabolic cone bore, the final F-mezzo has a fairly straight bore. The instrument illustrates that Sax must have been working on other types of bore profiles long before he coined them in the 1866 patent.

what happened to the tenor saxophone?

Sax's later tenor saxophone all of a sudden has a wider bore and wider conicity than his original instrument! The design of the tenor has shifted a step up toward the alto and in the process had turned over the coherence of the original quartet. Why has Sax done this? There is, as far as I'm aware of, no written evidence about this shift in design other than the general statements in the 1866 patent. We can just ascertain that bore profiles change around 1866.

The original tenor had worked well, yet it proves to feel a little distant and a slightly 'unwilling' in its lower range, a bit chamber music-like too (according to my own findings). Maybe Sax judged that it didn't live up to his expectation of an open air instrument; anyway, the updated and widened design certainly does: it feels like the modern tenor saxophone, wide open and forceful (again, according to my own findings).
There is yet something else remarkable about the shift in tenor design: the truncated length in the post-1866 tenor has increased with about 2½ centimetre. You cannot see this in the profiles of the instruments presented here, one of which is high pitch whereas the other one is low pitch, but it becomes evident when we compare tone holes positions in both instruments, recalculating for the difference in pitch. And not only that, but the tone holes in the post-1866 instrument tend to be just a little bit smaller as well! Especially this last feature would make you suspect the tone produced to be more introvert. Yet the opposite is the case, which goes to show the decisive influence of the bore profile. As it turned out, with an odd exception, everyone followed.

yet another possibility

There is yet another possibility as to why Sax has changed his bore profiles: acoustical stability. What leads me to the suspicion of acoustical stability is my own attempt in building an alto saxophone with a parabolic bore (see «A TRIBUTE TO SAX», THE MAKING OF THE BORE). It turns out that, while a low-C is still no problem at all, it is difficult to make it go down to a low-Bb in a stable fashion, near impossible to reach to a low-A. The instrument easily starts to produce involuntary multiphonics. To suppress this tendency the bell and the tube part directly preceding the bell both need to have a certain width. Here we find two striking aspects of the original bore profiles, the parabolic body and the wide bell, combined out of necessity. The same holds true for the wide mouthpiece: its inner cavity is not only essential to intonation, but also to the stability of the instrument in its lower range. Again, it is certainly no coincidence that the parabolic bore and the wide mouthpiece were mentioned in one and the same paragraph in the 1846 patent.
The straightened bore of the post-1866 saxophone on the contrary has no trouble at all in reaching its lowest note and even does so in a stable manner with a narrower bell. This observation sheds a new light on the changes made to the tenor saxophone as well, all the more since the original tenor saxophone feels slightly unwilling in its lower range. In changing his design, Sax not only repaired the problem of a tenor that is somewhere near acoustical instability, but also created conditions that proved to be indispensable for the lengthening to low-Bb in the years to come (although the low-A would still prove to be awkward) and the use of a narrower mouthpiece.

On the basis of these measurements we cannot but conclude that Sax around 1866 largely abandons his original design. It need not surprise us that (most of) his competitors went on with the new profiles, which thus became our modern day standard for the saxophone. It proved to be a sufficient answer to the criticism on the intonation characteristics of the instrument and unintentionally made future developments possible. So let's never ever say again that Sax did not update his saxophone; on the contrary, he redesigned his saxophones fundamentally within only 20 years after their birth certificate. It's just that in this phase of development he was more interested in acoustics than in mechanics. Finally we begin to understand why in the 1866 patent the new dispositions of the cone were described as improvements.


Musically speaking, when you're interested in reviving the original sound of the saxophone, you might consider whether to choose from the pre-1866 instruments or from those after, as their profiles (and their sounds) are rather different.