Mouthpieces Does a high baffle mouthpiece tip opening affect the brightness? (mythbusting)

[Pete Thomas]

The myth (or is it?)​

I had always assumed like many other players that, all other things being equal, high baffles with narrower tip openings would sound brighter and conversely with wider tip openings they would sound less bright (assuming the same baffle dimensions). This is based on the knowledge I gained from reading forums - I should have known better. I now know that to a certain extend this is a fallacy, but it isn't that simple.

Some context for my new found wisdom:​

A customer asked about ordering a tenor PPT with a tip opening of 150 thou, a gobsmacking number 12 facing. The Hooliganissimo model. But, like me, he assumed that the baffle ought to be higher to compensate for the wider tip. He assumed that relative to the wide tip, the baffle was effectively lower and so would need to be made higher to compensate as he wanted it to be no less bright than his 130 and 140 PPTs.

So I discussed this with the expert Ed (Dr) Pillinger who makes the mouthpieces and his advice to not make the baffle higher was quite a revelation.

The theory that busts the myth​

As some of you may know, Dr Pillinger's original doctorate research into embouchure and oral cavity involved the use of an artificial embouchure. The artificial embouchure had a simulation of a person's lower jaw and lip which could be gradually tightened against the reed as air was pushed through (by a pump) to simulate the player blowing into the mouthpiece.

His apparatus had a simulation of the inside of a player's mouth that could be increased and decreased in volume and was designed to measure whether or not the oral cavity size made a difference. But he also made an interesting discovery about jaw tightness.

What he found was that as the air blew and he tightened the embouchure there was a fixed and measurable point at which the reed started to vibrate and sound started to be generated. So he could keep the mechanical embouchure at this point, remove the mouthpiece and measure exactly how "bent" the reed needed to be (amount of deflection) before making a sound. He was surprised to fine that (even with a relatively wide mouthpiece), the reed needed to bent a very large amount.

So this suggests that the wide tip opening effectively becomes much much smaller than we might imagine, hence the relative distance between the baffle and reed on a very wide tip may be about the same as it is on a medium tip opening. The point of a baffle is to accelerate the airstream and so this is likely to be similar whether it is a medium or wide tip.

Put it another way: on a very wide tip you need to apply more pressure in order to bend the reed up enough to get a sound to generate, and this effectievly closes the tip opening. But I also take into account that I find wider tips more versatile anyway.

However the difference may become audible once you get down to smaller sizes. For example I have noticed that although there is very little if any difference in brightness between an 9* and 11, there is quite a marked difference in tone between an 8* and a 7* - the 7* being not insignificantly brighter - especially when pushed.



So I had always thought that to get the best sound from a high baffle you needed a wide tip. But that is only part of the story.

 

[turf3]

It seems to me that the amount of preloaded bending on the reed depends on air flow - so that you need to clamp further with low air flow and don't need to clamp as much with higher air flow. This would imply, then, that open facings can "take more air" than less open facings, which seems to be how most people experience them; also that you've got to use more effort to play softly (less total air flow) with wide facings.

So I'd suspect that at low and medium dynamic levels, the reed might very well be the same distance from the baffle for a 150 and a 110 mouthpiece, because the player's got to clamp the reed down on the 150 till it's at about the same place as the reed on the 110; but at loudest volume, the player may be able to reduce embouchure pressure on that 150 and get more total reed movement. Don't know what that means for baffle position for a wide facing mouthpiece being played at very high dynamic levels.

 

[Saxlicker]

Far from being an expert myself, doesn't stop me swallowing every personal experience and nerding out over everything I read.
Of course I dismiss somethings that don't tie up for me and take mental note of other things that strike me as meaningful.
So it's interesting that he found a fixed point where the reed starts to vibrate and produce sound.
Only very recently I tried one of the new Tone Edges so called 'Wabbitts'
In the same room within a couple of minutes a friend tried it too. So much difference in sound between the 2 of us.
Yes of course the reed, the ligature, horn and the player.
But I reflected on the fact that all the significant and contributing changes to the sound happened before the reed breaks from the first part of the rails and the table.
Beyond it and into the chamber is a constant regarding how it deals with the airflow after the vibration.
So for that vibration and sound starting point, if variation of the air pressure and air speed don't change the starting point, I now have 2 constants.
Or was the air pressure and speed always the same in his study?

Edited for more clarification.

 

[JSL]

Very interesting Pete. I've always assumed that with a high baffle, a more open tip will produce a darker sound than a narrower tip. This was based on my experience early on playing a couple of high baffle mpcs with tips in the 7 range. Those mpcs were very bright, almost 'shrill'. Then I picked up a .115 (8*) RPC mpc with a relatively high baffle and it wasn't nearly so bright. Later on, Ron made me and RPC with a .120 (9) tip and a high baffle that had a fuller, if not darker tone, than the .115 (8*). However, the baffles, while equally high, had a different shape. The 8* mpc had a more rounded baffle, while the 9 tip had a baffle with a sharp vertical drop off (which I think added more edge). Anyway, I've always assumed that a more open tip was needed to compensate for a high baffle mpc (adding warmth), than for a low rollover baffle. From what you wrote, it looks like there may be exceptions.

However the difference may become audible once you get down to smaller sizes. For example I have noticed that although there is very little if any difference in brightness between an 9* and 11, there is quite a marked difference in tone between an 8* and a 7* - the 7* being not insignificantly brighter - especially when pushed.

Based on your statement in the quote above, it may be that the 'myth' holds for tip sizes in the range between around 7 and 9*, but not necessarily for larger tip openings. I haven't played anything larger than 9*, so have no experience in that 'extra-wide' tip range.

 

[lig]

Interesting takes. I had always felt that a monster tip opening on a piece with the same height baffle did sound darker. It was definitely true for me on Dukoffs back in the day between D7/8/9 tips-chambers.

Then again - when I had a .130 tip I went down to a 2 reed from a 3 or 3.5 so it was never a direct apples to apples kind of situation and I never recorded back to back to confirm anything.

Nowadays it's all about the playability of the setup to me.

Very happy to be in that .108 zone with an Ishimori 3 reed on tenor and find that my happy place on alto is .088 with a 2.5 Ishimori.

With that in place I strive to get the tone I'm after through my playing.

 

[Pete Thomas]

Based on your statement in the quote above, it may be that the 'myth' holds for tip sizes in the range between around 7 and 9*, but not necessarily for larger tip openings. I haven't played anything larger than 9*, so have no experience in that 'extra-wide' tip range.

Yes that is a great summary of my longwinded post.

 

[Dr G]

The relationship between tip opening, baffle height, and frequency response is non-linear.

 

[PigSquealer]

The relationship between tip opening, baffle height, and frequency response is non-linear.

Where’s your data or citations to prove this?

 

[Pete Effamy]

What he found was that as the air blew and he tightened the embouchure there was a fixed and measurable point at which the reed started to vibrate and sound started to be generated. So he could keep the mechanical embouchure at this point, remove the mouthpiece and measure exactly how "bent" the reed needed to be before making a sound. He was surprised to fine that (even with a relatively wide mouthpiece), the reed needed to bent a very large amount.

Could there be a constant relative measurement (ratio ?) between reed deflection (point of vibration starting) and tip opening? Does a baffle distort this measurement? Or are there too many factors to make such a measurement:

Facing length
Tip Opening
Rail / tip thickness
Baffle / shape of baffle
How much mouthpiece in mouth
How much lip on reed
Amount of air pressure

...

 

[Pete Thomas]

Sadly I don’t think Ed has his artificial embouchure any more. His aim was in determining where size or shape oral cavity affected sound, so the measurement of reed deflection was just a fort of by-product of that research.

 

[David Roach]

I always tought that Vandoren's Jumbo Java T75 was a terrible mouthpiece, but that the T95 Jumbo was great.
Similarly the A35 Jumbo was gross, but the A45 Jumbo became an industry standard.
As to why Vandoren didn't alter the baffle heights of the closer tippped pieces, I guess it comes down mostly to money; but I suppose not doing so gave a wider variety of available colours.

 

[Grumps]

Bright. Dark. Don't matter. When I switched to very open tipped mouthpieces over twenty-five years ago it opened up an entire spectrum of sound variation for me that I had not known. It was finding my true preference in allowing me to put more air into my horn; softly or loudly. They were built for me and I knew it from the very first moment I played a .134 on tenor.

 

[LostCircuits]

High baffles allow you to shape the MPC in a way that can create a brighter tone. But you can take a bright high baffle piece and "break" the edge of the baffle and the more radius you put on, the mellower/darker it'll get. That's my personal experience and it's been the subject of a few discussions with Ron as well.
Now, he may have planted a bug in my head but I am looking at my sop pieces, high baffle, B-style that were paint peelers when they came off the mill and after "deburring" the baffle they are anything but bright. 0.070 tip opening.
@Grumps played one of them so you may get a second opinion.

 

[Grumps]

@Grumps played one of them so you may get a second opinion.

That soprano mouthpiece played very well for me and I'd have no problem gigging with it. I think I was getting a variety of sounds with it on a few different instruments. Heck, I might have bought it from you if you offered!

What was funny that I took from that day was your reaction when you saw the space between my tenor reed and the curve of the tip opening I was using. I thought you were used to that sort of thing with RPC.

 

[Dr G]

Where’s your data or citations to prove this?

It’s a simple boundary conditions matter. We see linear behavior in the “normal” range where reeds are designed to operate, and that behavior changes at extreme values. Go to a sufficiently large tip opening, and the system stops working at all. Where do those changes in response occur?

The other side of the question is “Why would you expect a reed to behave in a linear way at extreme tip openings?”

 

[LostCircuits]

That soprano mouthpiece played very well for me and I'd have no problem gigging with it. I think I was getting a variety of sounds with it on a few different instruments. Heck, I might have bought it from you if you offered!

What was funny that I took from that day was your reaction when you saw the space between my tenor reed and the curve of the tip opening I was using. I thought you were used to that sort of thing with RPC.

Heck yeah, my own tenor piece is 0.125. But I don't see this with others very often, hence my reaction: "OMG, this is huge" 😀

 

[LostCircuits]

It’s a simple boundary conditions matter. We see linear behavior in the “normal” range where reeds are designed to operate, and that behavior changes at extreme values. Go to a sufficiently large tip opening, and the system stops working at all. Where do those changes in response occur?

The other side of the question is “Why would you expect a reed to behave in a linear way at extreme tip openings?”

Are reeds behaving in a linear way at all?

 

[Dr G]

Are reeds behaving in a linear way at all?

Likely not, but I’m considering a limited range of “normal” tip openings that approximate linear behavior.

 

[mizmar]

Are reeds behaving in a linear way at all?

I'm sure not in the sense of being modelable as a simple harmonic oscillator or other basic tricks producing nice, analytic, solutions. For a start they're asymmetric. Second "normal" reed usage means the tip comes to a crashing stop on the MP, and has to wait for something external before springing up again- so not really a continuous, differentiable equation!

... I'd'v understood the issue as being that, within some dynamic range, they behave regularly and continuously - but can be driven to behave erratically
?