You know how when you write the same word over and over it can begin to look wrong? Researching this article felt like that, because I can’t actually find any primary sources calling these resonators “Tonex”. ToneX was a pad, ToneX was also a brand for some mouthpieces, but I cannot find any documentation to say that these resonators were ever called Tonex- Selmer simply called them tone boosters. More on that below the measurements.
Anyhow, what we have come to call Tonex resonators were the reusable resonators that came with Elkhart-assembled Selmer saxophones from around 1939 to around 1959, at which point they became plastic (and still reusable for a while).
They are measured in 16ths of an inch, and originally came in 12 sizes that were reduced to 9 by the time they became plastic. The first casualty was the smallest size for palm keys, which turned into a large flat rivet that I think is a modified brake pad rivet (which was also a slight bit larger than the “Tonex” reso it replaced). Photo of that in the gallery.
The sizes#
Twelve sizes, numbered 1 to 12. By the time Selmer went over to nylon boosters around Mark VI 80,000 they dropped three of them- 6, 9 and 12- and kept the numbers where they were. That is why the nylon numbering has holes in it.
Sizes are written as sixteenths throughout- 14/16" rather than 7/8", 17/16" rather than 1-1/16"- so the ladder is easy to read.
| Size | Metal # | Plastic # |
|---|---|---|
| 5/16" | 1 | 1 |
| 7/16" | 2 | 2 |
| 9/16" | 3 | 3 |
| 11/16" | 4 | 4 |
| 13/16" | 5 | 5 |
| 14/16" | 6 | does not exist |
| 15/16" | 7 | 7 |
| 17/16" | 8 | 8 |
| 18/16" | 9 | does not exist |
| 19/16" | 10 | 10 |
| 21/16" | 11 | 11 |
| 23/16" | 12 | does not exist |
Metal resos that are undamaged should measure really close. Plastics were injection molded and the thin edges are a tiny bit variable, but not by a huge amount.
Metal “Tonex” Sets#
Measured off of original sets. As tonehole sizing changed over the available models (Balanced Action, Super Action, Mark VI) and also the resonators themselves were reduced in available sizes, this is to be treated as suggestive rather than gospel. Your horn may differ. If you have measurements from original sets, please send them to me!
Numbers and quantities only- these say what is in the set, not which key takes what.
| # | Size | Alto | Tenor | Bari |
|---|---|---|---|---|
| 1 | 5/16" | 5 | ||
| 2 | 7/16" | 1 | 6 | |
| 3 | 9/16" | 3 | ||
| 4 | 11/16" | 4 | ||
| 5 | 13/16" | 2 | 1 | |
| 6 | 14/16" | |||
| 7 | 15/16" | 4 | 3 | |
| 8 | 17/16" | 1 | 2 | |
| 9 | 18/16" | 1 | 3 | |
| 10 | 19/16" | 1 | 1 | |
| 11 | 21/16" | 3 | ||
| 12 | 23/16" | 2 |
Alto is blank for now. Will be updated soon.
Two adjustments for spec: a horn with a high F# takes another of the palm key size, and a low A baritone takes another of the low Bb size.
Plastic “Tonex” Sets#
For these, we have a fantastic primary source document. Same thing for the nylon boosters, taken off the Selmer factory sheet below- #52 alto, #54 tenor, #55-55A baritone.
| # | Size | Alto | Tenor | Bari |
|---|---|---|---|---|
| 1 | 5/16" | 4 | 4 | 2 |
| 2 | 7/16" | 4 | 1 | 2 |
| 3 | 9/16" | 1 | 1 | 2 |
| 4 | 11/16" | 4 | 4 | 2 |
| 5 | 13/16" | 1 | 1 | 3 |
| 6 | 14/16" | |||
| 7 | 15/16" | 1 | 4 | 2 |
| 8 | 17/16" | 4 | 3 | 3 |
| 9 | 18/16" | |||
| 10 | 19/16" | 2 | 1 | 2 |
| 11 | 21/16" | 3 | 4 | |
| 12 | 23/16" | |||
| Total | 21 | 22 | 22 |
Naming and other info#
Selmer called them Tone Boosters. In Selmer’s 1952 catalog they said:
“Exclusive Selmer Tone Boosters. Large dome-shape discs applied as shown above. Fit to within 1/8” of tone hole rim. Do not confuse with small, inert rivets. Selmer Tone Boosters actually boost tonal output, brighten tonal quality."
Note that “Tone Booster” is the same name Selmer used for the plastic ones a decade later. Also note that 1/8" claim, which is a useful metric for resonator maximalists and also notable that they necessarily backed away from it later when they reduced the total number of sizes available.
Octave pads get no resonator. The upper stack C# on alto seems to have gotten no resonator.
The removal of the smallest reusable tone booster was sometime in the early VI run, I think, but I am not sure and I have not seen it written down anywhere. The disappearance of the sizes that are not accounted for in the plastic versions may have happened earlier than the switchover (around 80k, 1959), but I am not certain. If anyone knows, contact me.
More on what original Selmer resonators look like in my video Repairman’s Overview: Original Selmer Saxophone Resonators.