Subject:
          Intonation Tweaks
    Date:
          Tue, 1 Apr 2003 14:30:45 -0800
    From:
          "Vidovic, Damir" <dvidovic@...>
      To:
          "Paul Coats" <tenorman@...>




Hi Paul!

I would be grateful if you could please elaborate on differences in
intonation effects
between pulling-out/pushing-in the mouthpiece versus the chamber size
enlargement/reduction. Since the latter action alters the chamber volume
only, while the
pulling-in/pushing-out tweaks the chamber volume AND the length, I have
been wondering
whether these 2 different modifications would alter the pitch of the
high notes (short
lengths) vs. the low notes (long lengths) in 2 distinct ways.

Best,

Damir

Damir:  YES!!! Exactly!  You have the right idea.  I HAVE fine tuned
intonation problems in this way.

For the saxophone to tune properly, the volume past the end of the neck
pipe must be the same as the missing section of the cone.  In fact, this
volume was used as a constant in the calculations of the bore and tone
hole placement in Adolf Sax�s formulas in his patent.

If the mouthpiece has a small chamber volume.. and the bore of the
mouthpiece past the end of the neckpipe is certainly part of this
chamber volume, then usually the mouthpiece has to be pulled out so that
the resulting volume is correct, in order to make the C2 (middle C) tune
to the correct concert Bb pitch (with the Bb saxes).  Then the internal
volume of the mouthpiece is long, making a long air column.

This does not affect the low register, as the tuning for the low
register is by VOLUME.  BUT, in the high register, the upper notes, from
about A on up into the palm keys, will be flat.  The resulting air
column is too long.

Yes, tuning in the low register is by volume, tuning of the high
register is by length.  I was surprised to find this.  But I have done
repeated experiments to prove this.  I don�t understand fully the
physics of why this is true, but it is.

If the mouthpiece has a large chamber volume, then the mouthpiece must
be pushed on very far onto the neck cork.  The low register tunes OK.
But the top notes in the upper register become very sharp, because the
air column is too short.

This shows up on soprano more than alto or lower saxes.  In fact, I made
a mouthpiece for one troublesome soprano in this manner� and this proves
what I said above.

I started with a Selmer S80 with F facing.  Using a �� diameter (12.7mm)
drill bit, I drilled into the bore, until the drill bit came up into the
window area.  Then I made a tube from �� diameter Delrin rod.  This rod
is sold by Ferree�s Tools for making replacement clarinet tone holes
(for the open fingered holes).  I drilled through the middle of the rod
with a 5/16� bit, so that the walls of the resulting tube were
approximately 1 mm thick.

I cut various lengths of this tube, and inserted them into the bore,
pushing them up to the back of the chamber area.  By using different
length tubes, I made the mouthpiece have different chamber volumes.

With no tube, the high notes went sharp.  With a long tube, about 14mm
long, the high notes went flat.  Of course, with the long tube inside,
the mouthpiece had to be pulled out to tune the middle C.

By cutting off a little of the tube each time, and trying it, I quickly
found a length that gave good intonation.

Remember, for each volume change, the mouthpiece must be retuned, the
middle C (C2) to concert Bb.  And each time, the low register would be
good, and it was only the high notes in the upper register that were
affected.

This is easily seen with the Rico Graftonite soprano sax mouthpiece.
The chamber is much too large for any soprano I have ever tried it
with.  It must be pushed on the cork so far that it almost touches the
neck octave pip.  And it plays very sharp on the high notes.

When we first obtained our bass sax, everyone (who did not have a bass!)
told us we would need a �large chamber bass sax mouthpiece�.  On the
other hand, we knew that many of the old pros used bari sax
mouthpieces.  With the large Woodwind mouthpiece, we had to push the
mouthpiece onto the cork so far it completely covered the cork.  The
palm key notes (both of them, D and Eb� no E or F� Hah!!!) were VERY
sharp.  With a smaller mouthpiece, a modified bari sax mouthpiece, the
mouthpiece fit in a more normal position on the cork, and the palm key
notes could be played in tune with little effort.

I hope this answers your question.  This is only one of the reasons that
not all mouthpieces work well with all saxes.

Paul


--
Link to Paul's articles from Home page of "Sax on the Web":

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Listen to Paul's MP3's at:

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and view photos.

Hi Paul,

Thanks for that informative letter. Since it applies allow me to reintroduce a quote that I posted some time ago from Fletcher and Rossings "The Physics of Musical Instruments":

"While the saxophone has a single reed like the clarinet, the mouthpiece effectively truncates the conical taper of the main bore and introduces significant changes in tone color. In order that the horn modes be as nearly harmonic as possible, it is desirable that the mouthpiece mimic the acoustic behavior of the missing apex of the cone. This can be done at two frequencies, and then fits reasonably well over the whole range. At low frequencies, the matching is achieved if the internal volume of the mouthpiece is equal to that of the missing conical apex, which requires that the mouthpiece have a slightly bulbous internal shape so that it acutally constitutes a sort of Helmholtz resonator. The high-frequency match can then be achieved by arranging the shape of the constriction where it joins the main part of the instrument so that the Helmholtz resonance frequency of the mouthpiece is the same as the first resonance of the missing conical apex, at which it is half a wavelength long."

This is interesting to me because it shows that it is not only a question of the interior volume of the mpc mimicing the volume of the missing apex, but also that the diameter at the end of the chamber (which along with the volume determines the Helmholz resonance frequency of the mpc) is important for tuning. 

First what this seems to suggest is that most modern mpcs of which I am aware do not meet the primary requirement for correct intonation--that the interior volume mimic that of the missing conic apex. Most of them (as opposed to the old classical mpcs) do not have a bulbous internal shape--the chamber is the same size as the throat--and have a high baffle to boot, further reducing the volume.

There doesn't seem to be any effort made to conform to the second requirement--that the free-air resonance match that of the conic apex--I wouldn't even know how to calculate that. But it is clear that both these factors are affected by Paul's tweak. One easy way to tune the Hlemholz frequency would be to narrow the end of the chamber with a thin ring of epoxy putty. This can be reshaped for some time before it begins to set and is firm enough to hold its shape during the initial phases of testing. 

Toby
  ----- Original Message ----- 
  From: Paul Coats 
  To: dvidovic@... ; MouthpieceWork Group 
  Sent: Saturday, April 12, 2003 1:49 AM
  Subject: [MouthpieceWork] Intonation Tweaks


  Subject:
            Intonation Tweaks
      Date:
            Tue, 1 Apr 2003 14:30:45 -0800
      From:
            "Vidovic, Damir" <dvidovic@...>
        To:
            "Paul Coats" <tenorman@...>




  Hi Paul!

  I would be grateful if you could please elaborate on differences in
  intonation effects
  between pulling-out/pushing-in the mouthpiece versus the chamber size
  enlargement/reduction. Since the latter action alters the chamber volume
  only, while the
  pulling-in/pushing-out tweaks the chamber volume AND the length, I have
  been wondering
  whether these 2 different modifications would alter the pitch of the
  high notes (short
  lengths) vs. the low notes (long lengths) in 2 distinct ways.

  Best,

  Damir

  Damir:  YES!!! Exactly!  You have the right idea.  I HAVE fine tuned
  intonation problems in this way.

  For the saxophone to tune properly, the volume past the end of the neck
  pipe must be the same as the missing section of the cone.  In fact, this
  volume was used as a constant in the calculations of the bore and tone
  hole placement in Adolf Sax's formulas in his patent.

  If the mouthpiece has a small chamber volume.. and the bore of the
  mouthpiece past the end of the neckpipe is certainly part of this
  chamber volume, then usually the mouthpiece has to be pulled out so that
  the resulting volume is correct, in order to make the C2 (middle C) tune
  to the correct concert Bb pitch (with the Bb saxes).  Then the internal
  volume of the mouthpiece is long, making a long air column.

  This does not affect the low register, as the tuning for the low
  register is by VOLUME.  BUT, in the high register, the upper notes, from
  about A on up into the palm keys, will be flat.  The resulting air
  column is too long.

  Yes, tuning in the low register is by volume, tuning of the high
  register is by length.  I was surprised to find this.  But I have done
  repeated experiments to prove this.  I don't understand fully the
  physics of why this is true, but it is.

  If the mouthpiece has a large chamber volume, then the mouthpiece must
  be pushed on very far onto the neck cork.  The low register tunes OK.
  But the top notes in the upper register become very sharp, because the
  air column is too short.

  This shows up on soprano more than alto or lower saxes.  In fact, I made
  a mouthpiece for one troublesome soprano in this manner. and this proves
  what I said above.

  I started with a Selmer S80 with F facing.  Using a ½" diameter (12.7mm)
  drill bit, I drilled into the bore, until the drill bit came up into the
  window area.  Then I made a tube from ½" diameter Delrin rod.  This rod
  is sold by Ferree's Tools for making replacement clarinet tone holes
  (for the open fingered holes).  I drilled through the middle of the rod
  with a 5/16" bit, so that the walls of the resulting tube were
  approximately 1 mm thick.

  I cut various lengths of this tube, and inserted them into the bore,
  pushing them up to the back of the chamber area.  By using different
  length tubes, I made the mouthpiece have different chamber volumes.

  With no tube, the high notes went sharp.  With a long tube, about 14mm
  long, the high notes went flat.  Of course, with the long tube inside,
  the mouthpiece had to be pulled out to tune the middle C.

  By cutting off a little of the tube each time, and trying it, I quickly
  found a length that gave good intonation.

  Remember, for each volume change, the mouthpiece must be retuned, the
  middle C (C2) to concert Bb.  And each time, the low register would be
  good, and it was only the high notes in the upper register that were
  affected.

  This is easily seen with the Rico Graftonite soprano sax mouthpiece.
  The chamber is much too large for any soprano I have ever tried it
  with.  It must be pushed on the cork so far that it almost touches the
  neck octave pip.  And it plays very sharp on the high notes.

  When we first obtained our bass sax, everyone (who did not have a bass!)
  told us we would need a "large chamber bass sax mouthpiece".  On the
  other hand, we knew that many of the old pros used bari sax
  mouthpieces.  With the large Woodwind mouthpiece, we had to push the
  mouthpiece onto the cork so far it completely covered the cork.  The
  palm key notes (both of them, D and Eb. no E or F. Hah!!!) were VERY
  sharp.  With a smaller mouthpiece, a modified bari sax mouthpiece, the
  mouthpiece fit in a more normal position on the cork, and the palm key
  notes could be played in tune with little effort.

  I hope this answers your question.  This is only one of the reasons that
  not all mouthpieces work well with all saxes.

  Paul


  --
  Link to Paul's articles from Home page of "Sax on the Web":

    http://www.saxontheweb.net

  or directly to Paul's articles at:

    http://www.saxontheweb.net/Coats/

  Listen to Paul's MP3's at:

                  http://briefcase.yahoo.com/tenorman1952

  and view photos.



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>>>First what this seems to suggest is that most modern mpcs of which I am
aware do not meet the primary requirement for correct intonation--that the
interior volume mimic that of the missing conic apex.<<<

I think nearly all meet this requirement.  The player adjusts the Mp on the
cork until this requirement is met.

>>>Most of them (as opposed to the old classical mpcs) do not have a
bulbous internal shape--the chamber is the same size as the throat--and
have a high baffle to boot, further reducing the volume.<<<

Most have a medium chamber that is the same size as the bore (the cork
diameter).  One could consider this a small bulb since the neck end ID is
smaller than this.
 
>>>There doesn't seem to be any effort made to conform to the second
requirement--that the free-air resonance match that of the conic apex--I
wouldn't even know how to calculate that.<<<

Me niether.  Empirical testing seems to be the way to go.  Squeeze throat
designs are common on soprano sax.  But this does not seem to be the best
design for the bigger saxes.

>>>But it is clear that both these factors are affected by Paul's tweak.<<<

Maybe.  I'm not sold that the Physics are volume & constriction vs volume &
length.  Paul was adjusting the length of his insert to reduce volume, not
the ID to reduce the constriction.  He was able to dial in the intonation
while maintaining a fixed ID constriction.

Paul understands Hemholtz resonators.  I haven't been interested enough to
delve into them.  I would if the best (most popular) mouthpieces out there
were bulb & squeeze throat designs.  It seems to me that long narrow high
baffle pieces more closely mimic the missing portion of the sax cone.  I
realize that Adolph Sax did not use them.  I just think he had a different
tonal concept than modern players do.  Who do you think he listened to? ;-)

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Hi Keith,

A couple of quick thoughts on your replies,


  >>>First what this seems to suggest is that most modern mpcs of which I am
  aware do not meet the primary requirement for correct intonation--that the
  interior volume mimic that of the missing conic apex.<<<

  I think nearly all meet this requirement.  The player adjusts the Mp on the
  cork until this requirement is met.
  As Paul pointed out the length of the air column and the chamber volume are interactive, so this is not necessarily true--one normally places the mpc on the cork for the correct air column length. Of course meeting both these requirements is impossible in all situations, since the air temperature has an effect, as well as the humidity. Probably most mpcs are in the ballpark to where the difference is not more than a few cents one way or the other.


  >>>Most of them (as opposed to the old classical mpcs) do not have a
  bulbous internal shape--the chamber is the same size as the throat--and
  have a high baffle to boot, further reducing the volume.<<<

  Most have a medium chamber that is the same size as the bore (the cork
  diameter).  One could consider this a small bulb since the neck end ID is
  smaller than this.

  Hmmm....that's true. I have some old old mpcs that have a chamber much larger than the cork size and I assumed that they wre probably closer to the ideal, but on the other hand they don't seem any better in tune than my modern mpcs. Probably worse as a matter of fact.

  >>>There doesn't seem to be any effort made to conform to the second
  requirement--that the free-air resonance match that of the conic apex--I
  wouldn't even know how to calculate that.<<<

  Me niether.  Empirical testing seems to be the way to go.  Squeeze throat
  designs are common on soprano sax.  But this does not seem to be the best
  design for the bigger saxes.

  >>>But it is clear that both these factors are affected by Paul's tweak.<<<

  Maybe.  I'm not sold that the Physics are volume & constriction vs volume &
  length.  Paul was adjusting the length of his insert to reduce volume, not
  the ID to reduce the constriction.  He was able to dial in the intonation
  while maintaining a fixed ID constriction.

  Paul understands Hemholtz resonators.  I haven't been interested enough to
  delve into them.  I would if the best (most popular) mouthpieces out there
  were bulb & squeeze throat designs.  It seems to me that long narrow high
  baffle pieces more closely mimic the missing portion of the sax cone.  I
  realize that Adolph Sax did not use them.  I just think he had a different
  tonal concept than modern players do.  Who do you think he listened to? ;-)

  I intend to play with some old mpcs and see if the constriction (via a ring at the top of the throat) really has any effect on the high notes. If and when I do I'll report back to the group what I find. If I can work out the math (I've totally forgotten my geometry of solids) I'll also try to work out the volume of the missing apex and compare it to some mpcs. I think that you are mistaken about long, narrow high baffle pieces being the correct volume--don't forget that at the same semi-angle that truncated apex is going to be something like six or eight inches long on an alto. I wont really know though until I do some measuring.
  On the other hand that fact that most modern mpcs seem basically in tune would support your argument.

  Toby


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The math to figure out the missing cone volume is straight-forward, but not
trivial.  Usually the neck ID is measured on each end and the length
between the ends is measured.  A flexible rule helps.  Then one assumes the
shape is a cone, not a parabolic profile solid of rotation.

The math and some examples are in Ferron's book: The Saxophone is My Voice.

I have done the calculations and compared them to the actual volume of
several of my mouthpieces when tuned for my playing.  They were close, but
not exact enough that I wanted to include "volume sizing" as part of my
refacing work.  I measure the volume by sealing the window area with tape,
filling the MP with water and then pouring the water into a graduated
cylinder.  I repeat the measurement 3 times.  Then I subtract the
calculation of the volume represented by the corked neck overlap.

The 2 volumes only agree by +/-10% or so.  You would think the player
factor would make them off in the same direction, but I get +/- variation. 
In all cases, I tried to tune to mid range notes, like F#1 and F#2.

It was an interesting exercise, but not real fruitful.

I have also compiled a list of 10 soprano length and volumes, not
subtracting out the length of the cork when tuned.  All but 1 had lengths
between 2.65-2.73".  Only a vintage stubby MP had a length of 2.38". 
Volumes measured from 6.5 ml to 8 ml.  The stubby MP was 7.5 ml.  For me,
the most in tune MP was the smallest volume one, but I use the others too.

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Toby wrote:

>      I intend to play with some old mpcs and see if the
>      constriction (via a ring at the top of the throat) really
>      has any effect on the high notes. If and when I do I'll
>      report back to the group what I find. If I can work out the
>      math (I've totally forgotten my geometry of solids) I'll
>      also try to work out the volume of the missing apex and
>      compare it to some mpcs. I think that you are mistaken about
>      long, narrow high baffle pieces being the correct
>      volume--don't forget that at the same semi-angle that
>      truncated apex is going to be something like six or eight
>      inches long on an alto. I wont really know though until I do
>      some measuring.
>
>      On the other hand that fact that most modern mpcs seem
>      basically in tune would support your argument. Toby
>      Please do!!!  And let us know what you find out.  I reported
>      my experiment, and we would all like to hear of any other
>      experiments done, in any other facet of mouthpiece design.
>      That is the purpose of this group.
>
>      One point, as I pointed out in my previous post, both
>      mouthpieces AND saxes have evolved over time.  That throws
>      one more group of variables into our work.
>
>      Paul
>
>
>
>
>
>
>
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--
Link to Paul's articles from Home page of "Sax on the Web":

  http://www.saxontheweb.net

or directly to Paul's articles at:

  http://www.saxontheweb.net/Coats/

Listen to Paul's MP3's at:

                http://briefcase.yahoo.com/tenorman1952

and view photos.

> >>>But it is clear that both these factors are affected by Paul's
> tweak.<<<
>
> Maybe.  I'm not sold that the Physics are volume & constriction vs
> volume &
> length.  Paul was adjusting the length of his insert to reduce volume,
> not
> the ID to reduce the constriction.  He was able to dial in the
> intonation
> while maintaining a fixed ID constriction.

Note from Paul:  I drilled the Delrin (r) rod to have an inner diameter
approximately the same as the ID of the opening of the neck.  By
changing the length of the tube insert, it not only changed the chamber
volume, but length vs volume, thus fine tuning the high end.  As I said,
and Keith repeated, the volume is changed by the player when he tunes
the sax to the correct pitch level in the low register.

>
>
> Paul understands Hemholtz resonators.

Well, I have a grasp.  And I play with speaker systems, having built a
number of them, both acoustic suspension (sealed) and ported.  A ported
speaker is a Helmholz resonator.  It resonates just below the range
where the woofer starts to roll off on the bottom end, and thus, extends
the frequency in that range.  But that is different from this.  I liken
the saxophone, its mouthpiece and conical body, more to a horn
speaker... a small driver mounted to a megaphone horn.  But in our case,
the horn is of variable length (changed by opening and closing tone
holes).

I have been trying to figure out how the math of the driver of a horn
speaker, and how it mates to the horn, relates to the
mouthpiece/reed/embouchure and how that mates to the saxophone.

It is interesting to note that Conn experimented with testing trumpet
bells using both a pneumatic driver (air and rubber lips) and also an
electro-mechanical driver (a little speaker).  This is because no two
players blow the same horn the same way twice.  Conn was trying to get
repeatable results.

Also, the work of Athur Benade, there are diagrams of how he used
electo-mechanical drivers to power a cylindrical bore, modeling the
clarinet.

And this all brings to mind the thing with the electral professor and
Santy Runyon many years ago, with the Theremin and sax.

> I haven't been interested enough to
> delve into them.  I would if the best (most popular) mouthpieces out
> there
> were bulb & squeeze throat designs.  It seems to me that long narrow
> high
> baffle pieces more closely mimic the missing portion of the sax cone.
> I
> realize that Adolph Sax did not use them.  I just think he had a
> different
> tonal concept than modern players do.  Who do you think he listened
> to? ;-)

It is quite interesting to listen to recordings I have of the old Six
Brown Brothers.  They were the first Victor Records recording artists
(starting about 1914 or 1915!!), and responsible for introducing the
saxophone to the general public in the US... bringing about the
"Saxophone Craze" of the 1920's.  Yes, their tonal concept was quite
different from ours.  We can approach this tone with the old round
chamber Conn and Buescher mouthpieces of that era, or later Rascher and
Caravan mouthpieces.  Also, the tip openings were much smaller, facings
longer, and reeds harder.  All of this combined to make the tone nearly
without edge.  It is difficult to tell, with many early recordings,
whether a bass sax or a tuba is being used!

Also, no one but the lead player used vibrato... absolutely straight
tone.  The lead player, Tom Brown, used a wide, fast, "nanny goat" (as
we call it now) vibrato.  This was not unique to the saxophone, but also
used with trumpet, violin, and voice.

A good example of this sax tone is heard in the old Auld Lang Syne, or
on the old Little Rascals / Our Gang comedies.

By the 1930's, the saxophone was used more as a section.  The vibrato is
narrower, more even, smooth, and slower.  The saxophone section began to
replace the strings in the "dance orchestra".  More volume, more "cut"
was needed.  The tone had begun to get a little "edge".

Mouthpieces and saxes ("Radio Improved") changed in order to fill huge
hotel ballrooms, to balance with the brass and project on radio
broadcasts.

And they have continued to change with the music ever since.

Paul

>
>
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--
Link to Paul's articles from Home page of "Sax on the Web":

  http://www.saxontheweb.net

or directly to Paul's articles at:

  http://www.saxontheweb.net/Coats/

Listen to Paul's MP3's at:

                http://briefcase.yahoo.com/tenorman1952

and view photos.

To make these test more useful, it would be best to do this across a
range of instruments, both vintage and modern.
 
My personal findings are that the modern Sop mpcs are definitely easier
to play in tune than the vintage counterparts.
 
Later
God Bless
Bootman
Richard Booth
www.bootmanmusic.com
 
-----Original Message-----
From: Paul Coats [mailto:tenorman@...] 
Sent: Tuesday, 15 April 2003 3:08 AM
To: MouthpieceWork@yahoogroups.com
Subject: Re: [MouthpieceWork] Intonation Tweaks
 
  
Toby wrote: 
I intend to play with some old mpcs and see if the constriction (via a
ring at the top of the throat) really has any effect on the high notes.
If and when I do I'll report back to the group what I find. If I can
work out the math (I've totally forgotten my geometry of solids) I'll
also try to work out the volume of the missing apex and compare it to
some mpcs. I think that you are mistaken about long, narrow high baffle
pieces being the correct volume--don't forget that at the same
semi-angle that truncated apex is going to be something like six or
eight inches long on an alto. I wont really know though until I do some
measuring.
On the other hand that fact that most modern mpcs seem basically in tune
would support your argument. Toby  
Please do!!!  And let us know what you find out.  I reported my
experiment, and we would all like to hear of any other experiments done,
in any other facet of mouthpiece design.  That is the purpose of this
group. 
One point, as I pointed out in my previous post, both mouthpieces AND
saxes have evolved over time.  That throws one more group of variables
into our work. 
Paul 
  
  
  
  
 


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Well Keith, you are several steps ahead of me. You didn't meniton that you were speaking from experience ;-)

I tried blowing across the end of my alto mpcs with the window sealed to see the resonant frequency and the notes produced were within two semitones of each other, which is reasonably close, considering that the two lower ones had longer shanks. I should do what you did and measure the volume excluding the throat using a graduate.

BTW did you know that that was one of Thomas Edison's tests for young engineers who wanted to work for him? He would give them one of his early lightbulb shells and ask them to figure out the volume. Most would sweat for hours using calculus, and when they delivered their estimates he would show them his method: he would fill up the glass with water and then pour it into a graduate...

The real question I guess is how quick a volume mismatch detunes the sax. Probably not a linear relationship. I have an old Brilhart metal bari mpc sitting around here that I stuck on a tenor just to test the facing. The tuning results were horrific! OTOH I have used both alto and tenor mpcs on my C Mel with equally good (or bad results). Actually the alto mpcs are better in tune than the two original C Mel mpcs I have. Those have such closed tips that you would need a #7 reed to play them! How did those guys do it?

Toby
  ----- Original Message ----- 
  From: Keith Bradbury 
  To: MouthpieceWork@yahoogroups.com 
  Sent: Tuesday, April 15, 2003 12:34 AM
  Subject: Re: [MouthpieceWork] Intonation Tweaks


  The math to figure out the missing cone volume is straight-forward, but not
  trivial.  Usually the neck ID is measured on each end and the length
  between the ends is measured.  A flexible rule helps.  Then one assumes the
  shape is a cone, not a parabolic profile solid of rotation.

  The math and some examples are in Ferron's book: The Saxophone is My Voice.

  I have done the calculations and compared them to the actual volume of
  several of my mouthpieces when tuned for my playing.  They were close, but
  not exact enough that I wanted to include "volume sizing" as part of my
  refacing work.  I measure the volume by sealing the window area with tape,
  filling the MP with water and then pouring the water into a graduated
  cylinder.  I repeat the measurement 3 times.  Then I subtract the
  calculation of the volume represented by the corked neck overlap.

  The 2 volumes only agree by +/-10% or so.  You would think the player
  factor would make them off in the same direction, but I get +/- variation. 
  In all cases, I tried to tune to mid range notes, like F#1 and F#2.

  It was an interesting exercise, but not real fruitful.

  I have also compiled a list of 10 soprano length and volumes, not
  subtracting out the length of the cork when tuned.  All but 1 had lengths
  between 2.65-2.73".  Only a vintage stubby MP had a length of 2.38". 
  Volumes measured from 6.5 ml to 8 ml.  The stubby MP was 7.5 ml.  For me,
  the most in tune MP was the smallest volume one, but I use the others too.

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I just reviewed the caculations and measurements I did of MP volumes 
a couple of years ago.  I mentioned that I thought they were only 
good to +/- 10%.  I think my disagreement was worse than that.  Using 
my main 4 saxes (SATB) and 2-3 MPs each, the analysis indicated that 
I should push in more or pull out more up to 11 mm!  This is about 10 
times more than I expected.  

My 60's Conn tenor was to push in 7-10 mm from where I think it is 
properly tuned.

My Yamaha 62 Alto was to pull out 1-2 mm.

My Yamaha 52 Bari was to pull out 4-8 mm.

My 20's Conn sop was to push in 11-12 mm (and I play it with looser 
chops than the MP test says I should, so it is already pushed in 
some).

There are numerous sources of potential error.  I would suspect my 
measurement of the neck taper to be a big one since an error here 
would bias all analyses on that particular sax.

I decided that even if I was to reduce the error a lot, I would still 
have too much descrepency to make this a useful analysis to perform 
regularly.  

I think volume tweeks are best done emperically.  Figure out whether 
you need to go larger or smaller, make a small change and test again.

I think the "errors" in tuning can be found in a careful reading of
Benade's papers, most of which are in modeling the clarinet
mathematically and experimentally, but it applies here, too, with sax.

There is one that deals with interactions of the player and the
instrument... oral cavity, trachea, lungs.

But we all knew this... you take 10 players, and have them play the same
sax, the same mouthpiece and reed, and you will hear 10 different
sounds.  So much for the high school band director that makes all the
kids play Yamahas with Selmer C* and Vandoren 3 1/2, so they will all
match tone and play in tune.

Paul



Keith Bradbury wrote:

>  I just reviewed the caculations and measurements I did of MP volumes
> a couple of years ago.  I mentioned that I thought they were only
> good to +/- 10%.  I think my disagreement was worse than that.  Using
> my main 4 saxes (SATB) and 2-3 MPs each, the analysis indicated that
> I should push in more or pull out more up to 11 mm!  This is about 10
> times more than I expected.
>
> My 60's Conn tenor was to push in 7-10 mm from where I think it is
> properly tuned.
>
> My Yamaha 62 Alto was to pull out 1-2 mm.
>
> My Yamaha 52 Bari was to pull out 4-8 mm.
>
> My 20's Conn sop was to push in 11-12 mm (and I play it with looser
> chops than the MP test says I should, so it is already pushed in
> some).
>
> There are numerous sources of potential error.  I would suspect my
> measurement of the neck taper to be a big one since an error here
> would bias all analyses on that particular sax.
>
> I decided that even if I was to reduce the error a lot, I would still
> have too much descrepency to make this a useful analysis to perform
> regularly.
>
> I think volume tweeks are best done emperically.  Figure out whether
> you need to go larger or smaller, make a small change and test again.
>
>
>                    Yahoo! Groups Sponsor


>
> Got a Mouthpiece Work question?  Send it to
> MouthpieceWork@yahoogroups.com
>
> Visit the site at http://groups.yahoo.com/group/MouthpieceWork to see
> the Files, Photos and Bookmarks relating to Mouthpiece Work.
>
> To see and modify your groups, go to http://groups.yahoo.com/mygroups
>
> Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

--
Link to Paul's articles from Home page of "Sax on the Web":

  http://www.saxontheweb.net

or directly to Paul's articles at:

  http://www.saxontheweb.net/Coats/

Listen to Paul's MP3's at:

                http://briefcase.yahoo.com/tenorman1952

and view photos.

I would think the player factor in my case would offset all the "errors" in
one direction.  They probably do, unless I approach each size sax a little
different.  The only sax that I play noticeably off the MP test for
embouchure is soprano.  

One could argue that my Conns differ from my Yamahas.  This appears to be a
bigger factor than the player factor.

Then there is variation from MP to MP (player and sax constant), which
should just be MP "error".

Its a real can of worms.

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