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The case for level toneholes
A lot of care goes into the manufacturing of higher quality saxophone pads to insure the felt backing is perfectly the same width throughout and that the thickness of the leather covering is consistent as well. The goal of course is to create as flat a surface as possible so that when the pad comes in contact with the tonehole that it eclipses the light the entire 360 degrees around the tonehole at exactly the same instant.
One of the variables that can make this level of pad seating much more difficult, if not impossible is to have a tonehole that is not perfectly flat which means the edge of the tonehole is not perfectly on the same plane around its circumference. Imaging laying a straightedge across a wavy surface. It will touch only at the high points of the wave and will make no contact whatsoever in the valleys. The illustration below shows the effect exaggerated for purposes of illustration (although I have seen some Chinese saxes almost this bad).
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This raises the question of how to deal with this problem and make the pad seal airtight.
Different approaches to seating pads
1. One method which is very old school is to use pads with soft felt backing and force deep seats into the pad to reach and cover the valleys in the tonehole surface. This was done in the past by clamping the pads tightly and putting the instrument into a "pad oven" or heating the key cups individually with a torch. One of the drawbacks to this method is that the felt changes over time and the pad seating lacks stability. Another problem this deep seating method creates is that it makes it very difficult if not impossible to regulate the keys that must close together with any degree of precision.
2. Another technique is to heat the keycup till the glue is in its "plastic" state and push and pull specific areas of the pad the distance required to make it conform to the irregular surface of the tonehole. This method can be effective, but it is time consuming and must be duplicated each time a pad is replaced. Another common concern is that pulling down on the pad can create air pockets in the shellac making the pad unstable over time.
3. A third system is to mechanically level and flatten the tonehole as much as possible without filing. This is done by using special dent tools inside the sax to push up the low areas, special tools outside the sax to "tap up" the low areas and "tap down" high spots. The proponents of this method claim that the integrity of the sax is maintained by doing this in place of filing. The critics claim that moving metal around inside the bore of the instrument has a far greater effect upon the sound wave that filing the tops of the toneholes. Another disadvantage to this method is that it is extremely labor intensive and time consuming.
4. A fourth system is to file the toneholes. In previous years this was done using special fine tooth flat files using a back and forth motion---or forth motion depending on who you talked to. Recent innovations by Jim Schmidt and Curt Alterac have taken tonehole filing to a new level by introducing diamond skin abrasives on flat brass disks creating a "rotary" file that can be safely used under power to quickly level toneholes to perfection.
Approaches that are currently popular
One hears by word of mouth in the repair industry that more and more saxophone technicians are using the diamond grit rotary files in their repad and overhaul work. One tech wrote on Delphi Band Instrument Repair Forum that his rule is: "if the key comes off the instrument, the tonehole checked and leveled if needed.
A common procedure among techs seems to be a combination of some of the above techniques. If the imperfection of the tonehole is significant the first step is #3 above to minimize the amount of filing as much as possible. When the tonehole is close to flat, then #4 is used to finish the tonehole to perfection. The last step when needed is #2 to put the finishing touch on the pad seating by making minute adjustments when the shellac is softened a bit.
Is leveling toneholes safe?
A recurring concern among sax players seems to be whether filing the toneholes somehow damages the "integrity" of the instrument or effects the playability in a negative way. To answer these concerns it is important to note the following:
- Every saxophone (supposedly :bluewink
has its toneholes leveled after they are drawn through the body or soldered on (less common) as part of the manufacturing process.
- There have been cases where some idiot filed a tonehole too much taking the edge right down to the body. These instances are few and far between and are never done at the hands of an experienced professional tech who knows what he/she is doing.
- The amount of the metal removed from the tops of the toneholes is miniscule in the vast majority of cases---especially when the tech takes the time to do as much as possible by raising low spots first. Miniscule means 1/000" inch or less.
- To show how slowly the diamond abrasive circular files remove material let me share this story. Rich Zimmerman who works at Music Medic in his sales pitch about how safe they to use are shared that when they first tried the rotary files under power, they were also concerned about techs damaging instruments. In order to test this they took an old sax body and measured the time it took under power using way too much pressure to file a tonehole down to the body of the sax. He said under these conditions it took 20 minutes to do so. When I use my rotary files on a tonehole, I generally count to 8 and then check. This takes about 8 seconds and in most cases the tonehole has been leveled in that amount of time. What happens Rich explained is that the diamond grit cuts more quickly when there are high spots, and when the tonehole is perfectly flat the cutting becomes slower because of the increased contact area.
How filing toneholes affects the pitch and playability
- The acoustic scientist C.J. Nederveen estimates that in order to raise the pitch by 10 cents, one would have to reduce the height of the tonehole by 20 percent of its distance. The measured height of a low D tonehole on a Selmer Mark VI alto is .125" on the shortest sides. Shortening the height of this tonehole 1/1000" with all things being equal would, by Nederveen's calculation, raise the pitch by .4 cents. That would take the frequency of your E from 392.00 hz to 392.0932 hz---hardly a perceptible difference.
Conclusion
Hopefully this information will help to better inform saxophone players about the in's and out's of leveling toneholes. Different techs will use different approaches to take their work to level they are satisfied. Many will achieve the same results using vastly different techniques depending on how they were trained and who they studied or apprenticed with. The only thing that matters is that both the tech and the customer are satisfied with the cost and the result. The best advice I can think of is if you have concerns, discuss them with your tech before he/she begins work. If you don't trust your tech's level of expertise, then it is time to find a new tech.
A lot of care goes into the manufacturing of higher quality saxophone pads to insure the felt backing is perfectly the same width throughout and that the thickness of the leather covering is consistent as well. The goal of course is to create as flat a surface as possible so that when the pad comes in contact with the tonehole that it eclipses the light the entire 360 degrees around the tonehole at exactly the same instant.
One of the variables that can make this level of pad seating much more difficult, if not impossible is to have a tonehole that is not perfectly flat which means the edge of the tonehole is not perfectly on the same plane around its circumference. Imaging laying a straightedge across a wavy surface. It will touch only at the high points of the wave and will make no contact whatsoever in the valleys. The illustration below shows the effect exaggerated for purposes of illustration (although I have seen some Chinese saxes almost this bad).
This raises the question of how to deal with this problem and make the pad seal airtight.
Different approaches to seating pads
1. One method which is very old school is to use pads with soft felt backing and force deep seats into the pad to reach and cover the valleys in the tonehole surface. This was done in the past by clamping the pads tightly and putting the instrument into a "pad oven" or heating the key cups individually with a torch. One of the drawbacks to this method is that the felt changes over time and the pad seating lacks stability. Another problem this deep seating method creates is that it makes it very difficult if not impossible to regulate the keys that must close together with any degree of precision.
2. Another technique is to heat the keycup till the glue is in its "plastic" state and push and pull specific areas of the pad the distance required to make it conform to the irregular surface of the tonehole. This method can be effective, but it is time consuming and must be duplicated each time a pad is replaced. Another common concern is that pulling down on the pad can create air pockets in the shellac making the pad unstable over time.
3. A third system is to mechanically level and flatten the tonehole as much as possible without filing. This is done by using special dent tools inside the sax to push up the low areas, special tools outside the sax to "tap up" the low areas and "tap down" high spots. The proponents of this method claim that the integrity of the sax is maintained by doing this in place of filing. The critics claim that moving metal around inside the bore of the instrument has a far greater effect upon the sound wave that filing the tops of the toneholes. Another disadvantage to this method is that it is extremely labor intensive and time consuming.
4. A fourth system is to file the toneholes. In previous years this was done using special fine tooth flat files using a back and forth motion---or forth motion depending on who you talked to. Recent innovations by Jim Schmidt and Curt Alterac have taken tonehole filing to a new level by introducing diamond skin abrasives on flat brass disks creating a "rotary" file that can be safely used under power to quickly level toneholes to perfection.
Approaches that are currently popular
One hears by word of mouth in the repair industry that more and more saxophone technicians are using the diamond grit rotary files in their repad and overhaul work. One tech wrote on Delphi Band Instrument Repair Forum that his rule is: "if the key comes off the instrument, the tonehole checked and leveled if needed.
A common procedure among techs seems to be a combination of some of the above techniques. If the imperfection of the tonehole is significant the first step is #3 above to minimize the amount of filing as much as possible. When the tonehole is close to flat, then #4 is used to finish the tonehole to perfection. The last step when needed is #2 to put the finishing touch on the pad seating by making minute adjustments when the shellac is softened a bit.
Is leveling toneholes safe?
A recurring concern among sax players seems to be whether filing the toneholes somehow damages the "integrity" of the instrument or effects the playability in a negative way. To answer these concerns it is important to note the following:
- Every saxophone (supposedly :bluewink
has its toneholes leveled after they are drawn through the body or soldered on (less common) as part of the manufacturing process.- There have been cases where some idiot filed a tonehole too much taking the edge right down to the body. These instances are few and far between and are never done at the hands of an experienced professional tech who knows what he/she is doing.
- The amount of the metal removed from the tops of the toneholes is miniscule in the vast majority of cases---especially when the tech takes the time to do as much as possible by raising low spots first. Miniscule means 1/000" inch or less.
- To show how slowly the diamond abrasive circular files remove material let me share this story. Rich Zimmerman who works at Music Medic in his sales pitch about how safe they to use are shared that when they first tried the rotary files under power, they were also concerned about techs damaging instruments. In order to test this they took an old sax body and measured the time it took under power using way too much pressure to file a tonehole down to the body of the sax. He said under these conditions it took 20 minutes to do so. When I use my rotary files on a tonehole, I generally count to 8 and then check. This takes about 8 seconds and in most cases the tonehole has been leveled in that amount of time. What happens Rich explained is that the diamond grit cuts more quickly when there are high spots, and when the tonehole is perfectly flat the cutting becomes slower because of the increased contact area.
How filing toneholes affects the pitch and playability
- The acoustic scientist C.J. Nederveen estimates that in order to raise the pitch by 10 cents, one would have to reduce the height of the tonehole by 20 percent of its distance. The measured height of a low D tonehole on a Selmer Mark VI alto is .125" on the shortest sides. Shortening the height of this tonehole 1/1000" with all things being equal would, by Nederveen's calculation, raise the pitch by .4 cents. That would take the frequency of your E from 392.00 hz to 392.0932 hz---hardly a perceptible difference.
Conclusion
Hopefully this information will help to better inform saxophone players about the in's and out's of leveling toneholes. Different techs will use different approaches to take their work to level they are satisfied. Many will achieve the same results using vastly different techniques depending on how they were trained and who they studied or apprenticed with. The only thing that matters is that both the tech and the customer are satisfied with the cost and the result. The best advice I can think of is if you have concerns, discuss them with your tech before he/she begins work. If you don't trust your tech's level of expertise, then it is time to find a new tech.
