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Discussion Starter #1
has anyone ever calculated how fast you can theoretically play. lets say e to f. spring rate determines acceleration rate of the key and hence max speed before it hits the stop. if it rebounds it might change thins if you had to go back to e. what would be the minimum key height before the sound distorts.

Has anyone done this? if done for all the notes and keys that would be really cool.
 

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Discussion Starter #2
it looks like 23 views but no comments.

It must be really hard or a really stupid question. I suppose how fast isnt a really a relevant question. fast and sound bad would be no good too.

I am still curious though if anyone knows anything.
 

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I'll bet there are a lot of variables that might come into play here.
I would think the 'downward' speed would be slower than the 'upward' speed with a stiff spring. Not so much with a lighter spring.
But I never was good with this type of thinking...
Maybe one of our more technical minded members will have some thoughts a little later.
 

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The formula is not hard (physics), but finding the correct numbers to insert into the formula is not easy (laboratory work).

The formula for the top repeat rate is that it is proportional to the square root of <the spring stiffness> divided by <the angular momentum of the key>. The angular momentum depends mostly on the pad size and the distance from the pivot.

Usually, the best spring stiffness is found by trial and error (engineering).
 

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Its not a stupid question, but its also not a universal answer either.

For the action to open fast enough but not rebound also must not be too heavy for the player, lets face facts, you can put a spring in which exhibits 300 grams of resistance to the movement of the key, but imagine trying to move 300grams of weight with just a finger tip for an hour session of playing. You would have cramps within minutes of playing

I have measured force required to close keys and force required for fast actions, this was done with local musicians, telling me what they like and dislike

A key can close and lift its own weight and be a very comfortable light action with as little as 30 grams of force applied, however the key to pad relationship must be perfect, no ifs or buts """perfect""", as 30 grams is not enough force to seal the tone hole and overcome a pad which closes at one point before another point

90 grams is a nice action, fast with some forgiveness to accomodate very minor discrepancys in closing sequence. Very minor.

120 grams is a fast action, some rebounding can occur, pads closing at one point before another is relly not to much of an issue.

150 grams is uncomfortable to the average player. Heavy feeling to the keywork.(side note, I find a lot of the older yamaha 23's exhibit tensions of around the 150, be that becuase they came out like that or be that becuase repairers have oversprung the action, I cannot answer)

Hope that helps with your question
 

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Discussion Starter #6
thnks sismo. i glad someone has gone to the trouble to measure and put some numbers to this. what was the typical force an a factory horn?

I see there are too many uncontrollable variables. sismo's approach looks like its much more useful for making a horn playable. force pushing down obviously is dependent on the player and hence uncontrollable. the variable pad contact, spring rate, damping, friction, etc. could probably be estimated/averaged but there would be significant room for variation.

that sort of leads to have you already had a discussion on optimum pad materials and design?
 

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The problem is there is no consistency even from a factory.
Lets pick a nice sax 82Z, from the factory Ive found tensions from 60-135, so this led me to the simple understanding that on an assembly line the builder simply kinks the spring, there really is no optimum setting, which is understanable as each spring will have a different tension, each key will offer a different resistance to being moved, the only way to achieve a uniform pressure is with a tech taking time setting each key. Its as simple as that.

As far as sax pad design, I have through negotiation with a manufacturer had my own sax pads made for me, we use close to 2000 plus sax pads a year, they may not work for others, but for me that are exactly what I look for in a sax pad. For the average handy diy person I recommend musicmedic for simplicity of ordering and decent product
 

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Say the E key is lifted. I could be wrong but I rather doubt that any player's finger leaves that key before the key fully opens.

Therefore the limiting factor is the speed of a finger.

Curve a hand and place all fingertips on a desk top. How fast can you move a single finger up and down. It's not very fast. I think springs probably move keys considerably faster. Maybe marginal for the low, heavy keys of a bari, with their large angular momentum. But then do you expect to hear an ultra fast, low trill on a bari?
 

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I just love low Bb to B (or even C) trills on bari.... How about we do low B to low C# folks.

There are some things that aren't reasonable -- I don't care who you are.
 

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now i realize your in CA but its pretty late and your dot is green. so your reading and writing not practicing to play fast.
If he practices at 10:50PM he'll lose his flat....

There are some things that aren't reasonable -- I don't care who you are.
That's kinda how I'm feeling about this thread.....
 

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So this is the thread I came up with when researching this question.
I have very high action on my tenor sax I also have more loose spring tension. It pops quickly but I do not have to press hard to get the key to close.
Now my question, unfortunately adds more to the physics. I can play my scales VERY WELL. When I get up to a very fast speed, like 325 bpm in 8th notes, I find that my scales going downward come out fine and is easy. Now on the other hand, when I try and play going up the scales are not even at all and in many cases some notes dont even speak.

Is this a key height or spring tension issue?
*when I play the scales are slower tempos the ascending scales do not have this issue. I discovered I was having this issue at the breakneck speeds.
 

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When I get up to a very fast speed, like 325 bpm in 8th notes, I find that my scales going downward come out fine and is easy. Now on the other hand, when I try and play going up the scales are not even at all and in many cases some notes dont even speak.
This just means that your fingers are stronger than the springs (going down, your fingers push the keys down; going up, the springs push the keys up).

An instrument such as the recorder (no springs or pads, just your fingers) will play just as fast in both directions.
 

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Discussion Starter #16
wow i forgot this one. i suspected that light springs didnt make a real difference in speed because of how fast you can get your finger out of the way. i played one alto at at the repair shop that had much lighter springs than mine. since it was the the techs horn, i bet he spent some time getting it to play so nice with, compared to my horn, lighter springs.

the pad seating issue and pads sismo brought up is interesting too. im surprised a better more forgiving material hasnt been found over the years. its still basically the same as done in the 1920's. maybe somethink that takes a little thermal set coated with teflon.
 

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When I get up to a very fast speed, like 325 bpm in 8th notes
At the moment I can play one semiquaver at 350 bpm.

Seriously, I have a similar issue about springs. Some of my horns are wonderful (SML) some are slow (Dolnet). I have the feeling that the "quality" of springs is more important than tension. I hope some repairer could enlighten us. I remember someone heating springs till they are red and cooling them in oil rather than water.
 

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People keep mentioning pads......
Should I be considering my pads as well?
And someone else mentioned my fingers being stronger then the spring tension. Should I lighten my fingers? My fingers are VERY light at the moment? So then should I add more tension to the springs?

HELP!! AHH TOO MANY VARIABLES!!
 

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And someone else mentioned my fingers being stronger then the spring tension. Should I lighten my fingers? My fingers are VERY light at the moment? So then should I add more tension to the springs?

HELP!! AHH TOO MANY VARIABLES!!
I just came back from my holiday, and picked up my tenor with slow springs and high action, leaving the Ferrari (best MKVI ever, perfect setup) in the case: all the issues disappeared!

As long as you do not have an immediate comparison, everything is fine.
Pads need to be replaced when they leak excessively.
 

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Fingers seem designed to tap down a lot better than they lift up. To do with the curved design and linkage to the forearm muscles that operate them.
So do fingers just prefer a bit of spring tension to help them lift?

Balance in the way the keys are mounted is a very significant factor. Especially with vintage saxes, some springs have to lift the weight of a key a lot more than just rotate it around its pivot. That means that unless the spring is a lot more powerful, it lifts the key sluggishly. If the spring is a lot more powerful, the little finger in particular has difficulty operating it, especially if there is very little leverage where the touch piece is, as is common on non-Selmer vintage instruments. Selmer had an excellent design engineer around Mark VI days, and that set the pattern for most modern horns.
 
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