We saw that the original cone shape, which Sax named parabolic, is no longer used, but we also saw that remainders are still to be found anywhere. Whether or not we still want to assign the designation 'parabolic cone' is primarily a matter of judgement. Actually and strictly speaking, for over more than a century not a single instrument is built according to the original cone shape anymore, but which details, that do not simplify our judgement, do we still meet:
The one single feature that all of Sax's pre-1866 instruments have in common, is that this latter reduction of conicity already starts in the straight part of the instrument. At the same time this is the only characteristic which you never find anywhere else and which therefore could be named a distinguishing feature of his early bore profiles. Seen over the full length of the instrument the sword profile shaped reduction of conicity with Sax starts earlier than in any later instrument – if at all.
Moreover, apart from the tenor saxophone, which constitutes a story on its own, saxophone bores have become narrower. This narrowing does not refer so much to entrance or end values of the cone, but to the width of the main cone, making Sax's first generation of instruments considerably wider than the modern. As a result, the volume of the truncation with Sax's early instruments is bigger than what is usual nowadays, for the soprano even up to a 40%. That means that these instruments must be played with a much wider mouthpiece, which in turn influences the composition of the sound produced. This diminishing of the truncation and with that the diminishing of the necessary mouthpiece volume is a development which is partly unrelated to changes in shape of the cone itself. But on the other hand it does mean that the use of an ancient wide chamber mouthpiece on a modern instrument is not the same as the use of this type of mouthpiece on the instrument it was originally designed for.
There are more differences between Sax's instruments and modern material than the bore alone. For one, these horns have only one tone hole (which in most cases is smaller as well) per position, which causes less disturbances in the tube than in modern day instruments. Also key height, especially in the soprano, is smaller and that too has a bearing on the sonority and finally their wall thickness is markedly thinner. So when we compare the sound of these old instruments with that of a contemporary one, we should realize that there are more differences at stake than those between their cone shapes alone.