Tuesday, May 16, 2017

How mouthpiece material matters - Thickness

In a prior blog, we looked at how mouthpiece material might matter.  There is a great deal of mythology about how a certain material might "resonate" and have some effect on how a mouthpiece sounds.  Using material science, available evidence, and common sense, we could find no evidence to support such a claim and, in fact, the more the claim is examined the more ludicrous it sounds.  

We could not find the "material matters" proof that some players were hoping for but there actually are some areas where mouthpiece material does matter.  At the beginning of the prior blog, there is a list of those areas where material makes a difference (production costs, weight, electrical conductivity, etc.).  Unfortunately, we couldn't find any evidence that related to sound production.  

We tried to decipher the statement that "Metal mouthpieces are not subject to the same tonal changes we note in hard rubber, since the average thickness of material used can do nothing but act as a damping effect on the reeds (sic) vibration."  Here, it is difficult to determine what is being stated.  Metal mouthpieces tend to be thinner than hard rubber pieces.  So maybe the claim is that the thinner the metal, the less vibration?

I devised a test to see whether thin metal had a damping effect on vibrations.  Here is the test equipment.

It turned out that not only could vibrations pass through metal, but the vibrations could be transmitted via a string to another piece of thin metal and heard at a considerable distance.  I call it "metallic resonance string theory."  Try doing that with a vulcanized rubber can!  

Maybe I have misinterpreted the "vibration in metal" assertions.  I do think that the thickness of the mouthpiece material can make a difference in how a mouthpiece plays.  But it is not in a way that is generally discussed when talking about mouthpiece material.  

To test a "material thickness matters" claim, I purchased two identical mouthpieces.  One showed up free in the case of a saxophone that I purchased on Ebay.  It is a Buffet mouthpiece that is embossed with the name of Buffet's line of Evette & Schaeffer saxophones made from the 1950's to the 1980's.  It is sort of a generic student piece, probably produced for Buffet by Riffault, and almost always seen in the common "C" facing.  

Although these are relatively common, when shopping for an identical mouthpiece for my test I learned a bit of saxophone lore.  The "C" facing used on Buffet mouthpieces has been interpreted as meaning that Buffet mouthpieces were made by Charles Chedeville!!! Charles Chedeville is another figure that has his own sax lore about using super-duper rod rubber in the creation of his mouthpieces.  There is no evidence, of course, but it drives up the prices of old mouthpieces if they are claimed to be connected to Chedeville.  Ignore the fact that Mr. Chedeville was dead and gone by the time Buffet tossed one of these mouthpieces into the case with every new student saxophone.  I assume that this sax myth explains why I lost several auctions and finally had to bid $30! for a matching old Evette & Schaeffer (E&S) student mouthpiece.  

Here is what they look like.

Now for testing the theory that the thickness of mouthpiece material matters.  

The E&S mouthpiece has a beak* that reminds me of a clarinet mouthpiece.  Other than one white plastic mouthpiece, like one of mine shown in this blog, I had never had a mouthpiece with this steep of a beak angle.  It felt like I was playing my contrabass clarinet.  The beak is actually not quite as steep and thick as the contrabass, but it has a much thicker beak profile than my vintage hard rubber baritone saxophone piece.
E&S tenor in front, BBb contrabass in rear.

That made me curious as to just how "thick" is a thick beak?  And from where does one measure?  For me, I found several old mouthpieces that I had used with tooth guards.  They had indentations that showed approximately where my teeth had rested on the beak.  It turns out that my right front tooth (the "upper right central" for you dentistry types) was the primary point of contact.  That was about 15 mm back from the tip.  But I'm not convinced that that point is always my point of reference when deciding whether a beak feels thin or thick.  It may actually be my lips (further along the beak) that gives the sensation of thickness and where to place the mouthpiece.  Regardless, I decided to use 15 mm as my reference point.

Here is the basic measuring technique.  Outside calipers

Measuring beak material thickness at 15mm from the tip.

Thickness of the E&S mouthpiece at 15 mm.

It turns out that whether the mouthpiece beak feels thin or thick doesn't directly correlate with whether the beak material actually is thick or thin.  Using an outside caliper shown above, I measured my hard rubber Link Tone Edge as being 3 mm thick at 15 mm back from the tip.  My metal Super Tone Master has a thickness of 2.2 mm at 15 mm.  But, my hard rubber Babbitt Artist (which shares a large chamber design with the Links) has a beak thickness of only 2 mm at 15 mm.  Finally, the E&S hard rubber mouthpiece has a thickness of a whopping 4.9 at 15 mm.  

It turns out that the metal STM has the second thinnest material but the thinnest profile.  By "profile," I mean the distance from the reed to the top of the mouthpiece.  That's what I actually feel when playing the mouthpiece, not the thickness of the beak material.  Again, I looked at that measurement based on the mouthpiece profile at 15 mm back from the tip.  Because of the steepness of the beak profile, this measurement can also vary.  It is possible to have a steep profile and a high baffle (by increasing the material thickness) or a low profile and a large chamber with little baffle (by thinning the material).  Or you could have the same beak profile and a large difference in material thickness.  Compare a Dukoff Super Power Chamber with a Link Super Tone Master.  Similar beak profile but a huge difference in material thickness (creating a high baffle in the Dukoff).

Here is how I measured the mouthpiece profile, again at 15 mm back from the tip.  This mechanic's ruler is 1 mm thick and end indexed, so it made measuring simple.
The hard rubber E&S.

The Link Super Tone Master.

The Link STM was 7.7 mm and the E&S was 10.7 mm, both measured 15 mm from the tip.  That means that my mouth is open an additional 3 mm when using the E&S mouthpiece.  Or, if I insert the mouthpiece based on the profile thickness, I would insert the E&S only 9 mm (not 15 mm) to get the same profile feeling.  Turns out that I don't do that.  I measured my right front tooth contact point on various mouthpieces.  It appears that I prefer to put the mouthpiece in 15 mm regardless of the beak profile (probably for ease of tonguing).  So a mouthpiece profile directly effects how wide my mouth is open.

The thickness of the beak material on the E&S mouthpiece (4.9 mm) means that I can alter the beak quite a bit.  Most people who make changes to a mouthpiece concentrate on modifying the lay, the baffle, the chamber, or all three.  But what might be the effect if I leave the lay and the interior alone and simply reduce the beak profile by reducing the thickness of the material on the top of the beak?  In other words, does material thickness matter?

I used a fairly aggressive woodworking rasp for the initial reduction in the beak thickness (while taking occasional measurements).  Then I used a file, then sandpaper, and finally metal polish.  Here are the two pieces shown in profile.  I ended up with a little bit of a "duck bill" profile on the mouthpiece in front.

The mouthpiece in front had the beak material reduced by over 2 mm right where my tooth makes contact and reduced even more further up the beak.  An interior 2 mm difference in the chamber shape and size would be substantial change and one would expect it to make a difference in how the piece played.  But a 2 mm difference in material thickness only on the outside of the beak?  It turns out that the exterior change also makes a difference.  The original piece seems sedate, almost bland.  Just what a student needs.  The modified piece played a little livelier.  They also tune a little differently.

It is the second characteristic that makes me believe that it isn't really the thickness of the material that is making the slight change.  It is likely that it is the size of the oral cavity that is the difference.  My mouth is closed by an additional +2 mm on the modified piece, which means that the profile is now 8.7 mm at 15 mm from the tip, closer to my STM than to the original E&S mouthpiece.  By making my oral cavity smaller, the piece is livelier.  Or it could be that, with the thinner profile on the beak, I'm putting it into my mouth slightly further, thus getting a slight boost in volume and a livelier reed action.  Or it could be a combination of the two.  

Closing my mouth more would also make the piece tune slightly higher.  Nobody uses a pitch pipe anymore, now that there are accurate digital pitch producing gadgets.  

But if you've ever used one, you know how much the size of your oral cavity can change the pitch.  If I can find mine, I'll add a video showing the effect of simply changing my oral cavity while blowing a concert C on a pitch pipe.  


(7/26/17 update:  I found my pitch pipe and made a video.  Here is what you are looking at.  I first blow a C on pitch.  For me, that means reducing my oral cavity smaller than what feels "normal."  Then, I reduce my oral cavity about as small as possible without squeezing off the air passage.  Then, I make my oral cavity as large as possible, both while trying to maintain a constant air flow (as that can also change the pitch.)  Then a little large and small.  All I want to show is the effect of changing the size of the oral cavity.  How wide my mouth is open effects how large and small I can make my oral cavity.  In other words, even the thickness of the pitch pipe will effect how the pitch pipe tunes and plays).

I don't own enough metal mouthpieces to measure a sufficient sample to see if and how much they differ from hard rubber pieces in their exterior dimensions.  It seems strange to think that the claim that metal pieces play louder and brighter may have some validation, but all due to metal being generally thinner and therefore the oral cavity being generally smaller and/or the mouthpiece inserted generally further.  That would mean that the difference isn't directly because of the material, it is because the material allows for a different oral cavity profile and placement in the embouchure.  

I could try putting the original mouthpiece further into my mouth, but I would have my mouth open considerably further and changing too many variables at once.  Because of the steepness of the original profile, I know opening my mouth wider offsets any gain in liveliness and (for me) makes reed control more difficult.  I tested this by fabricating a ridiculously thick "tooth guard."  My ridiculously thick tooth guard only required me to open my mouth an additional 5mm on the original E&S mouthpiece, but it was like trying to speak without being able to close your lips.

So I have found another way in which material matters acoustically on a woodwind mouthpiece.  The thickness of the material can effect the size of the oral cavity because it can control the profile of the beak.  The thickness of the material can also effect where you place the piece in your mouth.  Not very exciting to those who were hoping for a secret mystical resonance created by a proprietary blend of ingredients.  Sorry.

P.S.  When I was done with this experiment, I couldn't help myself and decided to put a different facing on the already modified E&S mouthpiece.  Nothing radical.  Just opening it up to .095" (a Link 6*) from the original .080".  The combination of thinning the beak and opening the tip really changed the piece.  Or maybe, Buffet-Crampon mouthpieces, including their Evette & Schaeffer student mouthpieces, really are made from a super-duper Charles Chedeville secret rubber recipe formulated in the nonexistent "Chedeville factory."  Like Aladdin's lamp, when I rubbed the Buffet mouthpiece (with a file), it released a Chedeville musical magic genie.  

I just added that for those of you who like fairy tale endings.  Google "Chedeville factory."  You will find that it never existed except in the minds of those who believe in a super secret hard rubber recipe that produces superior acoustics.  Those who can hear the difference can also imagine a fictitious factory.

Where's Charlie?

*  I know that a lot of players reading this blog use a different terminology for parts of a mouthpiece.  For this article, a beak isn't the entire mouthpiece.  The beak is only the thin area placed in the mouth.

Sunday, April 9, 2017

Enlarging the Shank on a Vintage Hard Rubber Mouthpiece

From time to time, you will find a vintage ebonite mouthpiece that has a smaller than normal opening.  It can be frustrating if the mouthpiece can't be put on your neck cork far enough to tune properly, or maybe it can't be put on the cork at all.  It is possible to use sandpaper, glued on a piece of dowel, to ream out the opening.  That is time consuming and you may ultimately find out it wasn't worth the effort.  Here's a solution that I came up with.

Ebonite is hard rubber.  More specifically, it is hard rubber at normal temperatures.  It actually has a melting point and, in fact, ebonite can be melted completely down and remolded.  We aren't interested in that, but what if we could heat it to its "yield temperature" (the temperature at which it can be flexed) and enlarge the shank opening?  That's what I did.

First, I needed something that would have the approximate conical shape as the cork on a saxophone neck (in this case, a tenor).  Then, I needed a way to heat the inside and the outside of the shank to above 160F (about 70C).  That's about the temperature that ebonite begins to yield but isn't going to actually melt (hopefully).  I came up with an inexpensive conical shape that could also be used to transfer heat inside the shank.

It's a common aluminum "ring mandrel," although this one is technically a ring measuring device.  An actual ring mandrel is made of steel and allows the ring to be worked or enlarged by using the mandrel as an anvil.  Aluminum is too soft for that and is generally only used for measuring.  This one has markings on it that show ring sizes (which differ by country) and a reading in millimeters circumference.  You can measure the neck cork on your saxophone, or use some charts to get a general idea of what is an appropriate tenor shank opening or, simply open the mouthpiece a little at a time to get the proper size.  The picture above shows a vintage tenor mouthpiece on the mandrel at about 52.75 mm circumference.  That is a diameter of 16.8 mm.  Tight for a tenor.

There are two nice things about using an aluminum mandrel.  First, it is can be easily cut.  It will be too long to fit into a tenor mouthpiece shank.  You will need to shorten it the appropriate amount for using it on mouthpieces.  Second, aluminum quickly transfers heat into the shank.  Here, I am using a hot air gun, on the lower setting, to slowly heat up the mandrel.  It will be impossible to not also heat up the shank on the outside, but that's okay as it needs to be heated as well.  I tried to not heat the mouthpiece table and not even get close to the lay.

After a few minutes of heating, I notice the familiar sulfur smell like you get when you rub a cloth hard on ebonite (also caused by heating the surface of the ebonite).  I wore a glove on one hand so that I could gently force the shank further on the mandrel when I got the shank hot.  I was doing all of this by myself, so I didn't use my infrared thermometer to actually read the shank temperature.  I would guess it was probably 160 to 180F.  Once it was hot, I needed to get on with my project and so I didn't take a temperature reading.

I gripped the barrel of the mouthpiece with the gloved hand and gently pushed it down on the mandrel, opening the shank by one millimeter in circumference (which increases the diameter by almost .32 mm).  Because the mandrel has grooves on it for the numbers, it isn't completely round.  I had to quickly remove the mandrel, rotate 90 degrees, and reinsert.  I did this several times as the ebonite was cooling, and then left it on the mandrel while it cooled down completely.

I then checked to make sure that I had not effected the table.  I was concerned that by expanding the shank I might also enlarge the area under the table and raise it so that the table was no longer flat.  I lightly pulled the table across 1500 grit sandpaper laying on a piece of glass.  The scuff markings showed that I hadn't effected the table.  Even had I affected the table, it wouldn't make too much difference if one were intending to put a new facing on the piece.  Getting the table flat would be part of that project.

You may find that when you are done, and the mouthpiece now fits your tenor, that it will not tune properly.  It could be that the vintage mouthpiece was manufactured specifically for a horn that had a smaller neck opening.  It was "tuned" to that particular horn.  Or, it could be that the mouthpiece was a poor design in both shank and chamber.  It simply was and is a dud. Or, finally, it could be that the mouthpiece appears to be a tenor piece, but is really a C Mel mouthpiece (as was likely the case with one of the mouthpieces that I was using).

I suspected that one of the mouthpieces I experimented on was a C-Mel.  That's not really a problem.  First, C Mel pieces aren't in demand and make good material to experiment on.  Second, ebonite has another interesting characteristic.  If heated back up, it will relax back into its prior shape.  It is possible to reheat, and as it cools, put the mandrel back in only to the 53mm mark and let the shank shrink back down.  No harm done.

Here is a picture of the shank opening at just under 54 mm circumference.  That gives a diameter of 17.15.  Much closer to a "standard" tenor shank.  Unfortunately, there appears to be no such thing as a "standard" tenor shank opening.  Here are some general measurements from a site that has complied them over the years.  One of the mouthpieces altered in this blog was a Rene Dumont, which was a trade name used by a U.S. wholesaler to give this piece a French sounding name.

The same process can be used on an alto mouthpiece.  You simply need to cut a little less off of the aluminum mandrel.  Since these aluminum mandrels are available for less than $10 on the internet, it's not a big investment to have one mandrel for alto and another for tenor.  Here is the alternative $2,000 machinist's version for alto.  That complex machinery looks like more fun, but it costs way more and takes longer.  And the article says that getting the bore perfectly round is difficult.  Not so with my quick-and-dirty method.

I haven't tried this yet with other plastic materials, like ABS or PMMA mouthpieces.  Actually, I haven't found any of those that have bores that are too small.  I do have a cheap Chinese ABS tenor piece that seems to be larger than normal.  Maybe I'll try to use heat and my mandrel to shrink it.

Thursday, March 30, 2017

Does Mouthpiece Material Matter? Part 2.

In Part 1, we looked at the idea that a certain "perfect" hardness of vulcanized rubber effects how a mouthpiece sounds.  With the help of a mouthpiece expert, the preliminary conclusion was that it does not.  We will now look at the published statements of another materials expert on whether mouthpiece material matters.

I have used Mr. Otto Link as an expert before.  We first find him working for Alexandre Selmer in New York before WWI.  We then find him working at an instrument repair shop with Frank Meyer (later of Meyer Brothers mouthpieces) in 1923.  Then he opens his own musical repair shop and (in small print) offers mouthpiece refacing.  Finally, years after Goldbeck receives a patent for a metal mouthpiece in 1920, Mr. Link begins producing what appears to be an identical metal mouthpiece under his own name.  

But there is a problem.  The production cost of Mr. Link's metal mouthpiece is fairly high.  Competitor's mouthpieces cast out of ebonite are undercutting his sales.  So he begins production of an ebonite piece.  To quote a 1940 Link sales pamplet: "By embodying the famous "LINK" TONE CHAMBER heretofore found only in our Metal Mouthpieces we have created a very popular Hard Rubber Mouthpiece which exactly fills the needs of of those musicians who prefer a hard rubber mouthpiece." Great, Mr. Link created an identical mouthpiece made of ebonite.  

But don't think that Otto Link was going to ignore the whims of those who desire mystical vibrations from materials.  His advertising goes on to state that his metal mouthpiece was made of bell metal.  Presumably the idea was that bells resonate, ergo, a woodwind mouthpiece made of bell metal (a specific bronze alloy) could ring like a bell or something.  Wait a minute.  How can Mr. Link possibly make an hard rubber mouthpiece to mimic his bell metal mouthpiece? What is the sound of a rubber bell?  None of this makes any sense.

We don't need to make sense if we can come up with some convincing gibberish.  Otto Link simply ignored the inherent contradiction in metal vs. ebonite vibration claims.  He realized that material science can be ignored.  Superficial hype is all that is required.  Simply make an unfounded allegation (e.g., Link hard rubber is "eburnated") and walk away.  Likewise, just claim that Link metal mouthpiece are made of "bell metal" with the understanding that the term is inexact and nobody will ever test.  Let others imagine what bell metal does for a mouthpiece.  Remember, musician's don't analyze matter, they just repeat claims that material matters. 

Let's assume that we are not manufacturing or selling mouthpieces and examine a "bell metal matters" claim.  Bell metal (bronze that is 78% copper and 22% tin by mass) has a nicer ring to it than brass (copper and 32-39% zinc) when formed into the proper shape of a bell.  The shape of the bell is all important in the clarity, length of resonance, and pitch of the bell.  Mr. Morgan, in his article referenced in Part 1, alludes to this when he states "Obviously an alloy with less copper content will be harder and more dense, with a greater capacity to resonate. If you have ever compared the sounds of a fine Zildjian cymbal with some of the lesser quality ones available, the difference is heard immediately."

Brass always has less copper content than bell metal (61% to 78%).  Therefore, according to our expert testimony, brass is harder, more dense, and has a greater capacity to resonate, all of which is completely wrong.  I think we have further evidence that our materials expert is not an expert.   

Let's unpack the ultimate claim that a brass and a bronze mouthpiece would "sound" different with some testing.  Next time the drummer isn't looking, take his Zildjian cymbal and bend it as best you can into the shape of a saxophone mouthpiece.  Now, which matters more, the cymbal shape or the cymbal material?  Yes, the material of a cymbal or bell matters, but only after it is formed into the proper shape.  We now have evidence that a mouthpiece shape effects the sound, but not whether it is 78% copper or 76% copper.

Of course, there is no sound at all unless you hit the mangled cymbal with the drumstick (or in the case of a bell, with the clapper).  Here, we can get philosophical, since we never actually strike a bell metal mouthpiece.  What is the sound of an unrung bell, grasshopper?  If you want to get really hippie dippy, watch the YouTube video linked above all the way through.  (If you can hear the difference between a mouthpiece alloy with 78% copper and one with 75% copper, this video is for you.)

It appears that bell metal doesn't matter on a mouthpiece.  Or more precisely, bell metal only matters if formed in the shape of a bell or cymbal and struck with a hard object.  Even when bell metal is the proper shape to resonate, it generally has only one responsive pitch (some metals, such as Monel, have additional harmonic responses for a given shape).   

A "bell metal" mouthpiece doesn't have what anybody would consider a pitch.  Trust me, no need to whack your Super Tone Master with a drumstick.  But if a Link metal mouthpiece could resonate at a certain frequency, as claimed, what would that best pitch be?  Mr. Morgan doesn't tell us, so we'll have to choose one.

How about Bb for tenor and Eb for alto?  Can you find them in this picture?  It is very important.  Not.  What is important to get from this picture is the understanding that metals, copper, bronze, silver, etc., don't resonate at a certain frequency.   Various metal alloys, when a certain size and shape resonate at a certain frequency.  Have you noticed that none of these bells are the size and shape of a saxophone mouthpiece?

In the web site linked above, the dimensions of a middle C tuning fork of steel (the common material for tuning forks) was recreated using different metal alloys.  Not surprising, each alloy has a different pitch.  Also not surprisingly, most tuning forks had only one pitch per alloy.  And also not surprisingly, each metal alloy resonated only when struck with a hard object.  So a "bell metal" mouthpiece could conceivably produce a single short duration "pitch," depending on its shape, but only when struck with a clapper (or drumstick).

Let's take a closer look at a famous Link "bell metal" Super Tone Master.  But first, here's a brass bell.  Yes, they make bells of both brass and bronze.  Mine's just brass.  You can see that, although brass isn't supposed to be magnetic, it responds to a rare earth magnet and slight magnetism is one way to differentiate between brass and bronze.


Next, I'm going to use the magnet on bronze.  This is a high quality bronze screw, sometimes called a boat screw.  It is more expensive than brass screws and they ring like a bell.  Just kidding about the bell part.


No reaction at all.  Next is an old Otto Link.


What?  That's not supposed to happen.  Let's take a closer look.  In the first video, you can see that the brass bell is brass colored.  In the second video, you can see that the bronze screw is bronze colored.  That's the other way to tell if something is brass or bronze.  Brass and bronze alloys have a different color and get a different patina with age.  Brass is more golden, bronze more reddish.  Here is a look at the metal used on an old Otto Link (balanced on the bronze screw).

Now what?  Metal Otto Links are made of two cast halves brazed together.  And you can see that this one is made of two different alloys.  Which one is bell metal?  I'm going with the right side.  That's the side that always sounded best.  Just kidding.  This is further proof that material doesn't matter and Mr. Link knew this.  Brass, bronze, whatever is most convenient to cast and machine at a reasonable cost. 

Apparently, different Link casting batches used different alloys and nobody could tell when playing them.  Just say that it's made of "bell metal" and let the suckers consumers make up the rest of the story.  To his credit, Mr. Link never proceeded further with claims about the magical properties of "bell metal."  I'm sure that he knew that there is no pitch or resonance produced without the shape of a bell, and being struck with a clapper, and being a particular size.  And he knew that it was possible to make a great mouthpiece out of either brass, bronze, or hard rubber.  So much for materials matter. 

Mr. Link did not, however, do any thing to stop the myths surrounding his "bell metal" and "eburnated ebonite."  Our other expert, Mr. Morgan, treads where even Otto Link, the heretofore King of Hype, dared not go when discussing metal mouthpieces.  "Metal mouthpieces are not subject to the same tonal changes we note in hard rubber, since the average thickness of material used can do nothing but act as a damping effect on the reeds (sic) vibration."  

Let me understand this; if you want a damping effect, use metal not rubber.  Forget about rubber baby buggy bumpers.  Metal dampens more than rubber?  That contradicts both my personal experience and the understanding of the manufacturers of rubber products.  A rubber bell resonates longer than a bronze bell?  In what world?

Next, Mr. Morgan claims that players want to use metal mouthpieces "because a long list of prestigious players used that type of mouthpiece."  But these unwitting rubes don't realize that "they have only heard a performance using all manner of electronic enhancement and simplification, either live or on CDs/records/tapes.  Therefore, what we hear may be from what the player, mouthpiece, and instrument actually sound like, due to the whims of the sound engineer, etc., altering the true sound."  

Okay, that's a lot to unpack.  First, we can assume that the player has heard himself play when not using electronic amplification and prefers the metal piece.  Second, we can assume that sound engineers can also alter the sound of a Shore 85 "perfect" ebonite piece to make it sound as good as a metal mouthpiece.  Third, a lot of performances aren't miked and the patrons don't turn away when somebody plays a metal mouthpiece in a completely acoustic setting.  So much for that materials matter claim.

Finally, with yet another claim that metal mouthpieces "naturally provide more damping of the reed than hard rubber," Mr. Morgan states that metal mouthpieces can actually work if "the basic design be the result of much acoustical and aerodynamic study."  Aerodynamic study, not this bogus claim again!  At what speed does aerodynamics come into play on a woodwind mouthpiece?  A.  30 miles per hour.  B.  150 mph.  C.  Never.

But my favorite statement is "Experiments show that a mouthpiece properly designed and made of good hard rubber will produce 30% more sound overall and play with a more centered sound."  What is 30% more sound?  More volume? More overtones?  More inharmonics?  50% more highs and 20% less lows?  Is any of that good?  

And why do other experiments, experience, and common sense show that metal mouthpieces are appropriate and appreciated?  The listening audience, which is responsible for creating the "long list of prestigious players," apparently groove on metal pieces.  What good is hard rubber's claimed "more centered sound" if fewer want to listen?  We have established that material matters in that it can create unfounded and unsubstantiated prejudice.

Finally, a specific mention is made of the "distinct quality of silver mouthpieces.  One metal which does have the capacity, given the correct alloy, to produce a distinct clarity of sound is silver . . . which resonates at frequencies conducive to the production of a richness of sound not present in most other metal mouthpieces."  And what is claimed to be the "resonant" silver alloy?  Sterling silver at 92.5% pure silver, of course.  Why is sterling silver so good?  Because sterling silver was once used for money.  That sounds expensive, so it must be good.*

Sterling silver is always 92.5% silver, but the rest can be an alloy of either copper, zinc, tin, etc. and it is still sterling silver. We know from our tuning fork website linked above that the particular metal used to alloy 92.5% silver would effect the resonance.  As we have seen with copper alloys, using zinc produces brass and using tin produces bronze, each with distinct resonance and only one called "bell metal." 

Apparently Mr. Morgan didn't know about the large variety of alloys called sterling.  Sterling is uniform only in the percentage of silver but, because of the various alloys, not in the variety of frequencies at which it will resonate (when formed into a shape that can resonate).  So much for the sterling silver mouthpiece nonsense. Darn science (and logic and experience and common sense).  

So what have we learned from all of this?  Material matters depending on what type of mouthpiece you are selling.  If you are marketing metal pieces, they ring like a bell.  If you are marketing rubber mouthpieces, your special ebonite recipe makes them resonate.  If you are marketing wooden mouthpieces, you will have to make something up.  On that, Mr. Link, Mr. Morgan, and I agree.  

Mr. Morgan may be on to something when he states that not the material, but the average thickness of material, can effect the way a mouthpiece plays.  I'm thinking about writing a future blog about that concept and will provide a link if I get around to it.

Here is the link to the "material thickness" blog.

*  Silver as a magical material for bells became famous after the Christmas song "Silver Bells" was recorded by Bing Crosby in 1950.  Although the title has a nice "ring" to it, silver bells are not common except as charm bracelet bangles.  Despite the perceived "richness" of sterling silver, bells from silver are not popular because of the relatively high pitched "tinkle" that they make in comparison to brass and bronze.  A strange coincidence as the song's author first called it "Tinkle Bells" until his wife explained her understanding of what the word "tinkle" means to women. 

Wednesday, March 29, 2017

Does Mouthpiece Material Matter? Part 1.

Yes.  Absolutely.  But probably not in the way you are thinking.  It makes a difference in how a mouthpiece is manufactured.  It makes a difference in the weight of the mouthpiece.  It makes a difference on the look and feel of the mouthpiece.  It makes a difference in the production cost of the mouthpiece.  It makes a difference in the flammability of the mouthpiece.  It makes a difference in the color of the mouthpiece.  It might even make a difference in the smell of the mouthpiece.  

I know what you are thinking.  Does it make any difference in the sound produced by the mouthpiece?  Not enough to detect or worry about.  But given that most players are looking for that special advantage provided by some mystical property of their instrumentation, we should look more closely at whether mouthpiece material matters "acoustically."  For that examination, we can use expert testimony, existing data, test results, and common sense.  If you don't have those things, don't worry, you can use mine.

With expert testimony, we need to be careful because there are many unsubstantiated claims out there.  Assertions like "plastic mouthpieces make you sound like a duck because duck calls are made of plastic."  We would have to resort to our other sources (existing data, test results, and common sense) to determine whether to believe that expert's statement.

I'm going to rely on two people as my material experts.  Mr. Otto Link (who I have used before as an expert) and Mr. Ralph Morgan.  I'm going to start with an article authored by Ralph Morgan and printed in the Saxophone Journal many years ago (Does the material used make any difference in how mouthpieces play?).  Right on point and the article is a wealth of assertions.  Let's see if we can answer that question with the evidence presented in the article.

The article begins by talking about wood mouthpieces, but the main take away is that wood mouthpieces are difficult to manufacture because of shrinking, cracking, etc.  Wood was abandoned when other materials became available.  So, materials that are more durable than wood and more uniform to machine than wood are preferable.  Material matters to the manufacturing process.  The article hints at the problem of there being hundreds of types of wood and that any claims of the effect of the vast variety of wooden mouthpieces would be silly.  Hint: don't put a mouthpiece made of dogwood in your case with a mouthpiece made of pussy willow; they will fight.  Things like that. 

Most modern players are not concerned with wooden mouthpieces, so we will begin with the article's discussion of hard rubber mouthpieces.  Mr. Morgan states: "Hard rubber became “the thing to use” after Harvey Firestone discovered how to vulcanize, or harden, natural gum rubber.  This happened none too soon since the need for clarinets and saxophones grew rapidly in the late 1800s."

Let's look at that statement a moment.   The U.S. Patent Office issued patent 3633 for the vulcanization of rubber on June 15, 1844.  Harvey Firestone was born on December 20, 1868.  Do you see a problem?  Harvey Firestone missed the first several decades of ebonite development because he wasn't born yet.  Harvey Firestone did get a patent related to vulcanized rubber.  His patent was for tires on horse drawn buggies, and later, automobiles.  Firestone was a contemporary of Henry Ford and became a millionaire as a result of pneumatic tires.  But a claim that Firestone "discovered how to vulcanize?"  It was Charles Goodyear who patented the vulcanization of latex rubber.  Ummmm, I'm going to be skeptical on all further testimony by this materials expert, okay?

Mr. Morgan then talks about the hardness of rubber measured on the Shore D scale.  Albert Shore developed a method to measure hardness of vulcanized rubber in the 1920s (long after ebonite had been successfully used for woodwind mouthpieces).  It is basically a spring loaded pin and the measurement is how far the pin deforms the test material without penetration.  Two different scales exist, Shore A and Shore D.  Shore A is for softer rubber and Shore D for harder.  

Ebonite is usually tested with a Shore D meter, which uses a sharper pin and 5 times more force than a Shore A durometer.   Ebonite is defined as vulcanized rubber above 70 on the Shore D scale.  Some of this is defined in ASTM D2240 if you are interested in the minute details.  It should be noted that ASTM D2240 states "No simple relationship exists between indentation hardness determined by this test method and any fundamental property of the material tested."  In other words, according to the American Society for Testing and Materials, rubber hardness means diddly about its acoustical properties.  I'm going to start from that point of view.

There are problems with Shore test accuracy, of course.  In effect, you are trying to measure a particular rubber's "squishiness," which (as you would imagine) is a rather "elastic" concept.   Manufacturers of the Shore meters usually state that because of test sample temperatures, operator error, etc., the meters are only accurate within + or - 5.  So a sample that reads 90 one day could later test as either 86 or 93.  Here is a YouTube video of using a durometer.  The pin tends to slowly extend if the durometer is held in place, so even the quickness of the reading effects the result.  

Another influence on the test results is the size of the test "puck."  ASTM D 2240 defines the size and thickness required of a test piece (the test must be conducted on a flat surface greater than 6mm thick and further than 12mm from the edge).  Because of this size requirement, a Shore durometer can't be used on an actual woodwind mouthpiece.  In fact, it can't be used on a cylinder.  Here is a video supposedly showing how to get a correct reading.  You can see that the reading varies because you can't get an accurate reading on a cylinder.

Durometer measurements are important for commercial and industrial uses of rubber and plastic, although whether it tests as Shore D 85 one day and Shore D 82 the next doesn't matter.  The test would be performed on a sample "puck" and the material is deemed fit for it's intended purpose when properly molded, cooked and cured.  So the manufacturing process also effects the Shore D number.  If the part manufactured is small and cylindrical, you have to simply guess that you have come close to the intended Shore D number based on the rubber formula and manufacturing process.  It clearly isn't an exact science.

But wait a minute.  What if we are not interested in the the durometer reading for industrial use?  What if we don't want to acknowledge the limitations of Shore D measurements?  What if we are only interested in the mystical musical properties of vulcanized rubber?  What if we have a theory that a Shore 85 ebonite mouthpiece produces a luscious harmonic melody and a Shore 82 makes a dull flatulent moan?

A "perfect Shore D mouthpiece" is basically what is claimed in the Saxophone Journal article.  How do we examine our expert's testimony when he makes claims beyond known material science?  Super accurate Shore D numbers aren't available, direct testing of a mouthpiece isn't available, yet it is alleged to make a huge difference in the sound of a mouthpiece.  

There are inherent problems with claiming that a specific Shore D test number is required for an ebonite mouthpiece.   At approximately 80C, ebonite undergoes a thermoplastic transition, i.e., it approaches it's "yield" temperature and becomes plastic again.  (At approximately 200C, ebonite becomes liquid).  The Shore D number for all rubber products drops with an increase in temperature.  It is the nature of the material.  Race car driver's understand this and use a specific Shore D tire based on track conditions, knowing that the tires will soften when warm.  Even hip skate boarders know this one.  It is why the garden hose feels stiff on a cold day and limp on a warm day.

We can't predict exactly how much a hard rubber mouthpiece softens with warmth (and we can't measure a mouthpiece), but we know that it drops.  ASTM D2240 says that all Shore D testing must be performed at temperatures below 30C.  My durometer states that it can't be used at temperatures above 30C.  Based on the stated accuracy of my meter, one can assume that temperatures above 30 would cause inaccuracies even beyond the meter's claimed accuracy of + or - 5.

My durometer instructions and the American Society for Testing and Materials also state that relative humidity must be below 80%.  High relative humidity causes rubber, including ebonite, to become more flexible.  Maybe not enough so that you or I can tell, but enough for an inaccurate reading on a Shore D meter.  Again, it could result in an error outside of the meter's + or - 5 accuracy.

Commercially available tables show that 10 degree changes in temperature would change the Shore reading of some rubber products by about 5.  I couldn't find any tables on the direct effect of humidity.  The initial Shore D rating, as well as different additives, tend to effect the amount that heat and humidity will reduce the Shore D number.  Basically, there is no way of knowing how much the heat and humidity changes will "soften" a particular mouthpiece that we have guesstimated to be Shore D 85. 

Since we can't actually perform the Shore test on a mouthpiece, let's do some hypothetical testing.  We will start with an ebonite mouthpiece that we believe is a perfect Shore 85 (based on a sample of the material prior to molding, cooking, and curing).  First, we put the ebonite mouthpiece in our mouth.  Then we blow moist, warm air through it for a few minutes.  We will have now raised the temperature of the ebonite to 32C (90F).  It has condensation on the inside, indicating 100% humidity.  Our hypothetical test has now created the conditions scientifically known to reduce the Shore number.  In fact, both temperature and humidity are now in excess of the requirements for an accurate Shore test.  In case you haven't noticed, we create these conditions every time we play an ebonite mouthpiece.

We don't need to know exactly how much blowing through an ebonite mouthpiece would change the Shore number.  We do know that our durometer (which was only accurate within 5 begin with) is no longer accurate.  Maybe the Shore number has changed by 6?  We can't tell because the ASTM D2240 test can't be used on a warm, moist mouthpiece.  So what is the Shore D number after playing an ebonite mouthpiece that started out as the "perfect Shore 85"?  82?  Less?  We wouldn't know because even if it dropped to 74 it's still ebonite, i.e., it's still hard rubber that holds it's shape.  It appears to be the mouthpiece shape, not some vague and changing Shore D number, that determines how ebonite plays.

And we don't need to know the Shore D number of a warm, moist ebonite mouthpiece.  At this point, we can rely on our experience and common sense.  Have you ever noticed that getting the mouthpiece warm and moist makes a perfect hard rubber mouthpiece unplayable after a few minutes?  No.  Have you ever heard the difference when an ebonite mouthpieces undergoes this dramatic change every time it is played?  No.  Nobody has ever noticed this because a Shore D fluctuation of >5 doesn't matter.  Conclusion: the range of Shore D fluctuation in an ebonite mouthpiece does not effect acoustics.

Even Mr. Morgan agrees that Shore D doesn't matter for mouthpieces when he goes on to talk about metal mouthpieces.  Shore D doesn't matter on metal pieces "since the average thickness of material used can do nothing but act with a damping effect on the reeds (sic?) vibration."  I have to admit, I have no idea what that statement means.  At least we can agree that Shore D claims are nonsense.

Okay, enough, enough.  Let's go on to our second expert, Mr. Otto Link.  I have used Mr. Link as an expert in another blog.  Since this blog is getting long, I'll start another one about Otto Link agreeing with Mr. Morgan that material doesn't matter.  I'll "Link" to it when it is written.