When analyzing facing curve shapes, it is difficult to know what kind of thought went into the resulting shape.  Radial facing mouthpieces are easy to visualize and are easier to machine if you are not using a CNC machine.   But template tracing machines have been around for a long time to allow other facing curve shapes.

If a measured facing curve shape is close to a radial curve, you need to guess if the variation is some other target curve or is the result of manufacturing variation.  If the difference is irregular bumps and flat spots, it is almost definitely a production problem.   But if it is a smooth difference, it could be intentional or a drift from the target curve.  

I see no reason for a facing curve that is flatter than a radial curve.  They typically have a kink in the curve near the table to get started.  Rounding out this kink always makes the mouthpiece play better IMO.

Some mouthpieces have parabolic-like shape that curves more near the table and gets flatter near the tip.  This could also be fitted with an elliptical section.  I see these in many good clarinet facings.   Vintage Links often have this shape and some modern makers have copied this shape for their reproductions.  I'm not a fan but they must work well for a lot of players.  To me they add resistance for the low notes and have less resistance for the high notes.  It is a very subtle difference in most cases.  Players could easily alter their reeds to play very well on this type of facing.  I also suspect that some players use their embouchure to close off just enough of the facing so the resistance bump near the table is taken out of play.  This is just a theory of mine.  

Many facings have an elliptical shape to varying degrees.  These are a little flatter than radial coming off the table then curve a little more near the tip.  I find this shape helps with low note response while adding a touch of resistance to help with palm key and altissimo response.  The aspect ratio of the ellipse captures how much of this effect is going on.  If close to 1, the target curve is most likely a radial curve.  Ratios of 4-5 I consider medium resistance.  Ratios of 8 or more I have seen in classical mouthpieces and sop sax mp facings.

Of course tip opening and facing length are still major considerations for resistance and intonation control vs expressiveness.    

> On Aug 29, 2016, at 1:37 AM, johangjonker@... [MouthpieceWork] <MouthpieceWork@yahoogroups.com> wrote:
> 
> [Attachment(s) from johangjonker@... [MouthpieceWork] included below]
> The pictures show two of the facings of alto mouthpieces I measured. Both are quite close to the radial curve. Most facings seem to be more open at the tip then the radial curve. But some facings have a facing that is less open at the tip, like the conn steelay. What is the purpose of this?
> 
> 

very well put, Keith…..I use a radial curve on all of my mouthpieces

> On Aug 29, 2016, at 7:16 AM, Keith Bradbury kwbradbury@... [MouthpieceWork] <MouthpieceWork@yahoogroups.com> wrote:
> 
> 
> When analyzing facing curve shapes, it is difficult to know what kind of thought went into the resulting shape.  Radial facing mouthpieces are easy to visualize and are easier to machine if you are not using a CNC machine.   But template tracing machines have been around for a long time to allow other facing curve shapes.
> 
> If a measured facing curve shape is close to a radial curve, you need to guess if the variation is some other target curve or is the result of manufacturing variation.  If the difference is irregular bumps and flat spots, it is almost definitely a production problem.   But if it is a smooth difference, it could be intentional or a drift from the target curve.  
> 
> I see no reason for a facing curve that is flatter than a radial curve.  They typically have a kink in the curve near the table to get started.  Rounding out this kink always makes the mouthpiece play better IMO.
> 
> Some mouthpieces have parabolic-like shape that curves more near the table and gets flatter near the tip.  This could also be fitted with an elliptical section.  I see these in many good clarinet facings.   Vintage Links often have this shape and some modern makers have copied this shape for their reproductions.  I'm not a fan but they must work well for a lot of players.  To me they add resistance for the low notes and have less resistance for the high notes.  It is a very subtle difference in most cases.  Players could easily alter their reeds to play very well on this type of facing.  I also suspect that some players use their embouchure to close off just enough of the facing so the resistance bump near the table is taken out of play.  This is just a theory of mine.  
> 
> Many facings have an elliptical shape to varying degrees.  These are a little flatter than radial coming off the table then curve a little more near the tip.  I find this shape helps with low note response while adding a touch of resistance to help with palm key and altissimo response.  The aspect ratio of the ellipse captures how much of this effect is going on.  If close to 1, the target curve is most likely a radial curve.  Ratios of 4-5 I consider medium resistance.  Ratios of 8 or more I have seen in classical mouthpieces and sop sax mp facings.
> 
> Of course tip opening and facing length are still major considerations for resistance and intonation control vs expressiveness.    
> 
> On Aug 29, 2016, at 1:37 AM, johangjonker@... <mailto:johangjonker@...>[MouthpieceWork] <MouthpieceWork@yahoogroups.com <mailto:MouthpieceWork@yahoogroups.com>> wrote:
> 
>>  
>> 
>> The pictures show two of the facings of alto mouthpieces I measured. Both are quite close to the radial curve. Most facings seem to be more open at the tip then the radial curve. But some facings have a facing that is less open at the tip, like the conn steelay. What is the purpose of this?
>> 
>> 
> 
> 

Sent from my Samsung Galaxy smartphone.
Plplpp-------- Original message --------
From: "STEVE GOODSON saxgourmet@cox.net [MouthpieceWork]" 
Date: 08/29/2016 9:07 PM (GMT+08:00)
To: MouthpieceWork@yahoogroups.cll
Subject: Re: [MouthpieceWork] Facing Curve Shapes



very well put, Keith…..I use a radial curve on all of my mouthpieces

On Aug 29, 2016, at 7:16 AM, Keith Bradbury kwbradbury@yahoo.com [MouthpieceWork] > wrote:


When analyzing facing curve shapes, it is difficult to know what kind of thought went into the resulting shape.  Radial facing mouthpieces are easy to visualize and are easier to machine if you are not using a CNC machine.   But template tracing machines have been around for a long time to allow other facing curve shapes.

If a measured facing curve shape is close to a radial curve, you need to guess if the variation is some other target curve or is the result of manufacturing variation.  If the difference is irregular bumps and flat spots, it is almost definitely a production problem.   But if it is a smooth difference, it could be intentional or a drift from the target curve.

I see no reason for a facing curve that is flatter than a radial curve.  They typically have a kink in the curve near the table to get started.  Rounding out this kink always makes the mouthpiece play better IMO.

Some mouthpieces have parabolic-like shape that curves more near the table and gets flatter near the tip.  This could also be fitted with an elliptical section.  I see these in many good clarinet facings.   Vintage Links often have this shape and some modern makers have copied this shape for their reproductions.  I'm not a fan but they must work well for a lot of players.  To me they add resistance for the low notes and have less resistance for the high notes.  It is a very subtle difference in most cases.  Players could easily alter their reeds to play very well on this type of facing.  I also suspect that some players use their embouchure to close off just enough of the facing so the resistance bump near the table is taken out of play.  This is just a theory of mine.

Many facings have an elliptical shape to varying degrees.  These are a little flatter than radial coming off the table then curve a little more near the tip.  I find this shape helps with low note response while adding a touch of resistance to help with palm key and altissimo response.  The aspect ratio of the ellipse captures how much of this effect is going on.  If close to 1, the target curve is most likely a radial curve.  Ratios of 4-5 I consider medium resistance.  Ratios of 8 or more I have seen in classical mouthpieces and sop sax mp facings.

Of course tip opening and facing length are still major considerations for resistance and intonation control vs expressiveness.

On Aug 29, 2016, at 1:37 AM, johangjonker@zonnet.nl[MouthpieceWork] > wrote:




The pictures show two of the facings of alto mouthpieces I measured. Both are quite close to the radial curve. Most facings seem to be more open at the tip then the radial curve. But some facings have a facing that is less open at the tip, like the conn steelay. What is the purpose of this?