Many repairers ( and many modern manufactures ) install saxophone pads by a method called “floating” (float padding). “Floating” is to make a layer of shellac on a key cup and float a pad on it. A large amount of shellac is used to fulfill the space between the key cup and the pad. Repairers can adjust the inclination of pads easily, so the method is widely used.
I think that “floating” has a serious defect. It cancel the function of sax resonators, and it makes the tone of the saxophone poor.
Resonators are objects that vibrate in response to other vibrations. So resonators must be elastic. The sound board of the piano and violin, the resonator of the “resonator guitar”, the microphone diaphragm, all resonators are elastic.
King, Martin, Selmer, Conn….. many old manufacturers used a small amount of shellac to attach pads. It was to make a space between the pad and the key cup. (It seems that Selmer still installs pads in this way.)
These are original pads from vintage saxophones. You can find a little shellac was used.
(1. Selmer Mark VI 2. Selmer Mark VII 3. Vintage Martin)
When you press the original resonator, it moves slightly. And you can find it is elastic. So the resonator can resonate with the vibration of the air column. It looks like a microphone diaphragm or a speaker cone. If there is no hollow space on the back side of the resonator, it is not elastic and does not resonate.
In “floating”, there is no space between the pads and the cups. So currently, most of the sax resonators make no resonance. I think that many repairers ( and many modern manufacturers ) think that the pad resonators are reflectors. And they think that the spaces are made by mistake.
When you make hollow spaces in the key cups, you will find that the resonators work and enrich the tone. You can get more complicated tone with much overtones. And you will also find that the type of the material of the resonators changes the tone. Many repairers and players can not find the difference in material because quite a lot resonators aren’t working.
However, “padding with space” also have a inferior point. Pads need long time “burn-in” like speaker cones. The pads just after installation make only small resonance. To get good resonance, players must have time and patience and skill.
I think “floating” was begun as a simple method to install pads quickly with low skill. It was also convenient for players because it was unnecessary to spend time for “burn-in”. It was easy both for players and for engineers. But engineers changed generations, the function of the pad resonator was forgotten. And many saxophones lost their original beautiful tone.