Regulation, Key Heights, and Lost Motion

[jbtsax]

I started to post this response in another thread, but decided it would be more appropriate under Repair and Maintenance - Saxophones

Oh, and never (as in NEVER, NEVER) ever have all of the ooo|ooo finger position pads on a saxophone regulated so as to place them all the same height from the tone holes. The "typewriter" like level keyboard that this will provide may feel great under your fingers, but the horn's intonation will suffer as a result. Uneven and funky feeling is the rule with a saxophone.

The rest of SOTSDO's response is excellent as always, however I must respectfully disagree with the above statement.

Lower Stack Regulation
Regulating the lower stack of a saxophone involves adjusting the feet of the F, E, and (sometimes) D keys in such a way as to contact the backbar of the F# and close it (and the G# and Bis) at the same time. Once this regulation takes place, the cork or other material at the bottom of the feet of the F, E, and D keys is added to or sanded so that there is no "lost motion" before the foot of each key touches the backbar of the F#. This process, which is the correct way to regulate a saxophone's lower stack automatically results in the keys being in the same plane when open just as they were designed to be at the factory.

Key Height, Venting, and Intonation
The key height of the stack is normally adjusted so that the most under-vented notes speak clearly. Under-vented notes are those that vent through an open tonehole followed by a closed tonehole. Some of these are called "crossfingerings". The under-vented notes on the lower stack are F# venting through the F tonehole followed by the closed tonehole E, and E venting through the D tonehole followed by the closed tonehole Eb. This height is determined by the timbre (clarity) of the note, not by its intonation. If a fully vented note is uncomfortably sharp, putting a "crescent" in the upstream side of its venting tonehole can solve the intonation problem without making the note stuffy or introducing lost motion. If a fully vented note is flat is the topic of another even longer dissertation.

Over and Under Venting
It is true that some players prefer the key openings to be higher than they need to be for more more volume and projection. The tradeoff, of course, is increased key movement which can affect technique. The rule of thumb is that once the key is raised approximately 1/3 of the tonehole's diameter, raising it higher has no additional effect upon the pitch or timbre of the note. Some vintage saxes seem to work best with lower key heights compensated for by pushing the mouthpiece farther onto the cork.

Upper Stack Regulation
The upper stack is regulated and adjusted using the same principles stated above, except is the small C key that is closed by the B and A keys, and the under-vented notes are the C and A. The only way to adjust a sax setting the key height of each key independently of the others as suggested in the quote above would create "lost motion" in the keyboard that would not be acceptable to players of even modest ability.

 

[Steve]

added to above.

Sometimes the lowerstack backbar gets bent over time - normally the top or bottom is a bar sticking out (see bottom picture for the lower D key), thus adding "lost motion" This is corrected with correcting the backbar versus adjusting the height or foot bumper. This also shows the mechanism in total.

Also, one must keep in mind, sometimes pads are installed at different heights depending upon the amount of adhesive behind it. This can also create everything being at different heights. An attentive tech will keep them at the same height.

It all comes down to how finely detailed the setup is on the instrument, and how the owner prefers it, but I prefer them all the same height.

 

[SOTSDO]

I did too, but...

...there was a Selmer service bulletin issued back in the 1970s (1973 or so, if memory serves) that cautioned specifically against that practice, along with a number of reasons why that it should not be the case, at least as far as Selmer instruments were concerned.

I had my baritone "brought back" from a typewriter-like level key work, and it helped the intonation by a considerable amount. (I never got the same done to my other three horns, since I used them so little, and I sold the lot about a year after having the (re)adjustment made.)

So, that's my source, and you have my testimony that it worked well, at least with Mark VI era baritones.

 

[clarnibass]

Oh, and never (as in NEVER, NEVER) ever have all of the ooo|ooo finger position pads on a saxophone regulated so as to place them all the same height from the tone holes. The "typewriter" like level keyboard that this will provide may feel great under your fingers, but the horn's intonation will suffer as a result. Uneven and funky feeling is the rule with a saxophone.

This is not clear enough IMO and, sorry to say, is also not looking at it from the point of view of the real way this mechanism works.

For a start, do you mean to have the upper stack and lower stack keys to have the same venting? Or do you mean each stack by itself? It is very different. See the explanation after the quote from jbtsax.

The rest of SOTSDO's response is excellent as always, however I must respectfully disagree with the above statement.

Lower Stack Regulation
Regulating the lower stack of a saxophone involves adjusting the feet of the F, E, and (sometimes) D keys in such a way as to contact the backbar of the F# and close it (and the G# and Bis) at the same time. Once this regulation takes place, the cork or other material at the bottom of the feet of the F, E, and D keys is added to or sanded so that there is no "lost motion" before the foot of each key touches the backbar of the F#. This process, which is the correct way to regulate a saxophone's lower stack automatically results in the keys being in the same plane when open just as they were designed to be at the factory.

I agree, but there's a basic principal that IMO is important to explain and understand (which I'm sure you already do). When two (or more) keys close together, sometimes they are on the same hinge and sometimes they are on seperate hinges. This is a critical difference and is also the reason why each stack can't have its keys adjusted seperately from each other. It is only possible to control the venting/height of each key, when closing together with another key, when they are turning on different hinges.

The lower stack is an example of keys that are on the same hinge. What this means is that when adjusted to close accurately and without double action, which is the way they are supposed to be, no single key can be changed without also changing the rest of the keys, introducing double action, or ruining the adjustment.

The adjustment of the lower stack F# keys (i.e. top key on the lower stack hinge, except when G# is also on the same hinge) to also close the Bis Bb is the opposite, where the two keys turn on different hinges. This means that it is possible to adjust each key for venting and still have both keys to close together at the same time.

So re what SOTSDO wrote, in general ("weird exceptions" mentioned later), it is only possible to move the entire lower stack or the entire upper stack as a unit. They can be raised or lowered, but they can't have heights of different keys adjusted inside each stack. So if the keys are adjusted correctly and there are intonation problems, it is not possible to have only one key height changed while keeping adjustment without double action. The upper stack having smaller tone holes and keys usually have the keys significantly lower than the lower stack.

There are a few possiblities to the problem you had, with "even" height causing bad intonation and "unevening" it to improve intonation.
1) There was double action causing incorrect key height that was fixed. It is very common for most players (regardless of level) to miss double action.
2) There was an adjustment problem that was causing the intonation problem, which was fixed while also changing key heights.
3) Only each stack was changed as a unit, changing the relationship between them and not individual keys, which can cause a different feel ("less even" for some players), eventhough each stack remained the same. If both stacks were adjusted to the same height, it can absolutely create problems as mentioned above. Changing an entire stack as a unit can also make it feel like the key became more or less even, because of the shape of the player's fingers.
It can also be any combination of these things.

The "weird exceptions" are ways that single keys in each stack can be somewhat changed seperately. This doesn't changethe venting, but can slightly change the feel for the finger. One option is to extend the touchpiece. The other is to use an "incorrect" thickness pad and tilt it in the key cup and/or align the key cup. This will also change the relatioship between the venting and the feel for the finger.
However, I don't know even one player (including all levels) who ever needed something like this for a stack key.

 

[jbtsax]

The adjustment of the lower stack F# keys (i.e. top key on the lower stack hinge, except when G# is also on the same hinge) to also close the Bis Bb is the opposite, where the two keys turn on different hinges. This means that it is possible to adjust each key for venting and still have both keys to close together at the same time.

Nitai, it is apparent that you have thought this through in some detail. Do you have a step by step sequence that you use once the lower stack is regulated to match the upper stack key heights through the bis connection without what you call double action?

When dealing with opposite hinges and keys moving in two different arcs, I am embarrassed to say that I still use more trial and error than keen mechanical know how to achieve the desired results. Moving the rod containing the two adjusting screws attached to the F# key (or rod) forward and back never seems to have any great effect upon the opening of the bis key in my experience. Any thoughts on this?

 

[clarnibass]

Nitai, it is apparent that you have thought this through in some detail. Do you have a step by step sequence that you use once the lower stack is regulated to match the upper stack key heights through the bis connection without what you call double action?

When dealing with opposite hinges and keys moving in two different arcs, I am embarrassed to say that I still use more trial and error than keen mechanical know how to achieve the desired results. Moving the rod containing the two adjusting screws attached to the F# key (or rod) forward and back never seems to have any great effect upon the opening of the bis key in my experience. Any thoughts on this?

I think I prefer to explain the principal.

When two keys on different hinges are linked, there is always sliding in the linkage. This is the difference from e.g. the lower stack, where the two parts of the linkage contacting each other remain the same regardless of how the keys move (which is the reason for the explanation above of why the venting can't be changed seperately without introducing double action or ruining adjustment). For a sliding linkage, the contact point is different whether the keys are pressed or not.

Using the F# to Bis Bb linakge as an example, you can see that when the F# (or any lower stack) key is pressed, the contact point is at a certain place on the Bis Bb key linkage arm. When you don't press any key, the contact point is at a different place. If you want to change key height of just the upper stack or lower stack, but without causing double action or a problem with adjustment, you need to change the contact point when keys are not pressed, but not when they are pressed (i.e. they are already adjusted to close).

For keys where this sliding happens along the length of a cork (or preferrably another material) glued to the arm, it is possible to shape the material specifically for this. In some cases moving the bar with adjusting screws (when there is one) will solve the problem (if there is a problem). In some cases I would bend the linkage arm or even grind parts off (I have also added material a few times).

I think I might have a very basic (and probably not too great...) diagram that I made, if you think it might help I can look to see if I find it (changed computers since then and lost some stuff so not sure if I have it).

 

[jbtsax]

Thanks for that explanation. I too have changed the curvature of the bis linking arm on occasion to adjust key heights and/or to remove lost motion.

My question specifically, is once the bis is adjusted to close with the regulated lower stack with no "double action" as you call it, do you follow a step by step sequence to adjust the upper stack regulation and key heights to the height of the bis key which has been determined by the contact of its arm with the adjusting screw coming from the lower stack?

The upper stack proceedures (in no particular order) as I see them are:

- Adjust the A touchpiece arm to close the A key
- Adjust the A foot to close the C key
- Adjust the B foot to close the C key
- Adjust the A touchpiece to close the Bis key
- Adjust the foot cork of the A or B to remove lost motion at the C back bar
- Adjust the foot cork of the A to remove lost motion between the A touchpiece and the bis key

Is there a logical sequence to this that you have worked out? I'm also asking this question to anyone who does repair, not just Nitai.

 

[simso]

...there was a Selmer service bulletin issued back in the 1970s (1973 or so, if memory serves) that cautioned specifically against that practice, along with a number of reasons why that it should not be the case, at least as far as Selmer instruments were concerned.

I had my baritone "brought back" from a typewriter-like level key work, and it helped the intonation by a considerable amount. (I never got the same done to my other three horns, since I used them so little, and I sold the lot about a year after having the (re)adjustment made.)

So, that's my source, and you have my testimony that it worked well, at least with Mark VI era baritones.

I would concur. Whilst under the fingers a level "typrewriter setup" feels smooth, it really IMO affects the tone. To regulate the lower stack to the same clearance as the upper stack muffles quite considerably the sound.

Selmers I find particularly bad for intonation on the lower stack, if you were to set everything up to minimise lost motion, some notes just dont sound right, when you rectify this you introduce lost motion which gives a clunky feel to the mechanism, to overcome this on some of our local players we have fitted high density foam in the regulation point and tech cork for final compressional adjustment, this minimises the lost motion but allows for different key heights to exist in a stack.

Steve

http://www.ultrainspections.com/Woodwind.html

 

[jbtsax]

The techniques that are most effective for making intonation and venting adjustments are described in detail in these two articles by Curt Altarac.

Setting Keyheights With the Balanced Venting Method

Tuning a Saxophone With Crescents

Completely removing lost motion is the professional repair industry standard here in the U.S. I don't know any of my colleagues who would even think of leaving lost motion in the keys---especially on a professional quality instrument. Once the "under vented" notes on each stack are made to sound clear by adjusting key heights, the remainder of the keys are set to a corresponding height. You can't have an "over vented" note since opening a key more than approximately 1/3 of the diameter of the tonehole has no additional effect upon the pitch or timbre of the note. At that point if a note is too sharp, a crescent can be used to move the venting tonehole. Lowering individual keys on either stack to bring a pitch down is not the answer.

As a player of over 50 years, I couldn't imagine having a key close first with a squishy feel and then a solid stop. That would feel just like a saxophone with thick puffy pads that hit first in the back before closing completely.

 

[simso]

I had a discussion at the pub a while back with Curt, regarding his methods. Over way to many of a beer from what I remember it was very informative.

The two listed above are only some of the processes he uses, he also uses bore liners, relocates octave vents, expands sections of the necks.

Curt has spent a lot of time developing these processes to suit his style of tuning.

There are many ways to tune a saxophone, some involve glueing bits of sandpaper inside as a "crescent", as per the above article, some simply rely on opening individual keys up, inferring one process is right and the other is wrong is simply narrow looking.

One should not assume when they make comments that they talk for all of the continents repairers, I would not be so bold as to say I know it all.

I have a staff of 4 repairers plus myself, we average 4000-5000 instruments a year, we still learn new things almost daily.

 

[jbtsax]

With that we shall have to agree to disagree. Have a happy holiday Steve and have one at the pub for me. I drank more than my share when I was younger and quit in '86.