The sound of a brass instrument starts with a buzz of the lips. When a non-brass player does this, the listener hears a raspberry and does not identify a specific pitch. However, when the same buzzing is directed through a reasonably-long pipe, a sound is with a focussed pitch is heard, something which the hearer would identify as a musical note. So it’s not the lips on their own which produce this sound but clarly the combination of these and the pipe, acting together, which brings about the effect.

The phenomenon was recognised in ancient times and the ability of a mechanical device such as a trumpet or horn to create such a magnificent and majestic sound led to its identification with power, prestige and the Gods in many different societies.

It is the cavity within tubes which possesses a property which leads to this phenomenon, the key characteristic being their length and end features. When a tube is blown as a brass instrument, it acts like one which is open at one end but closed by the lips at the other. Although the lips open and close as they are buzzed, at their maximum open condition, they still cover most of the tube’s end diameter.

Thus, one end of the tube, being open is at atmospheric pressure while the other, being blown by the lips, is at a higher pressure and, as the sound wave within the tube needs to accommodate that condition, their can be only a limited number of configurations of sound wave within it. the most-basic of these configurations is shown in the diagram below.

diagram

In this condition, when the lips buzz at the end of a mouthpiece, each opening sends a puff of air, from the lungs, down the tubing of both the mouthpiece and its instrument’s tubing. This combined passageway is referred to here as the windway. It is the combination of these successive brief increases in air pressure which, when falling on the eardrum, are detected as sound by the ear. The successive pulses of air combine to form a sound wave which which you might have seen portrayed as in the diagram below.

diagram

However, as each small puff of air travels down the tubing, it pushes the small plug of air ahead of it down towards the bell end of the instrument. It can do this because the area of the tube ahead of it is of comparable area. The ease with which it can do this differs between cylindrical and conical instruments (trumpet Vs French horn) and this affects the sound output.

However, when the small block of air reaches the end of the bell, it suddenly faces a massive increase in the volume of air it is trying to push forward as it is pushing against the entire atmosphere. Naturally, this presents a massive limitation to its movement as the atmosphere pushes back against the plug of air travelling down the tubing. So great is this resistance that some of the air in the tube fails to escape and is reflected back down the instrument’s tubing. It is as if some of this air has hit a brick wall which prevents its escape. Physicists refer to resistance felt by the air as it moves down the tube as impedance and to the conditions at the end of the tube as the end impedance discontinuity as conditions at that point are not continuous as has been the case along the tubing.

Nevertheless, despite reflection taking place at the tube end, some air does escape and that’s why we hear the sound of the instrument. Just how much escapes is very dependent upon the shape of the tubing at the point where the air leaves the instrument. You may have seen the demonstration in which someone blows a hosepipe like a brass instrument. It works but its a very muted affair. The moment they add a funnel to the end of this, it is transformed. It sounds both louder and different.

The ‘louder’ bit is, therefore, as you now know, because more of the air is escaping from the hosepipe. This is because the passage from a small tube diameter to that of the entire universe has been aided by the presence of the funnel whole diameter has increased gradually, i.e., the end impedance discontinuity has been reduced considerably. So, the resistance to the passage of the air is proportional to the increase in area of the space into which it is travelling. When the air from the hosepipe alone meets the atmosphere, that’s a huge increase and most of the air is reflected. however, when it meets the beginning of the funnel, the diameter has increased only slightly and, hence, presents relatively little resistance. This effect carries on down the funnel and, by the time the air reaches the atmosphere, the shock of the open air is much less and more energy is able to escape into the atmosphere.. When the funnel is given a flare, such as on the bell of a modern brass instrument, the end face of this is pretty-much like a flat plate, enabling a considerable proportion of the energy in the air to escape into the atmosphere.

On some instruments, such as the modern French horn, the flare is very exaggerated so as to reduce the pressure needed to excite the air in a very-long tube.

The reflected air travels back up the instrument’s tubing, eventually reaching the lips. As the increaded pressure blip meets the lips, it either holds them closed or forces them together. Either way, the air column is not passive with respect to the player but exerts a considerable measure of feedback on the lips which synchronises the movement of the lips with the vibration of the air column within the tubing. This why it is impossible to blow open notes on a brass instrument other tan those which are part of its natural harmonic series.

The mouthpiece is the part of the brass instrument where the player and instrument meet. When placing the lips up against the mouthpiece, these do not form a flat surface as some of the lips dip down into the cup of the mouthpiece. Just how big an effect this is depends upon the actual structure of the player’s lips. If they are thick and fleshy, more lop enters the mouthpiece cavity. This explains why one cannot be categorical about which mouthpiece suits any one beginner as each individual possesses the lips which nature gave them. Some players might be better off with a wider mouthpiece than others while some might be better suited to larger instruments with their correspndingly larger mouthpieces.

The PeakTone model breaks the mouthpiece down into separate bits so that you are able to edit individual element or parameters, changing the nature of your mouthpiece as you go along. The reasons why you might want to do this are many and varied and a few are discussed below. Firstly though, the general terminology is shown below as you and I need to be talking the same language.

How Mouthpiece Parts are controlled in the PeakTone Model

In the PeakTone Model, you are offered some 23 different controls with which to adjust your mouthpiece. These however, are grouped for convenience so that you can concentrate on aparticular area of the mouthpiece without having the distraction of all the other controls around. The way these are grouped is shown below on the diagram.

As the above diagram shows, the various parts of the mouthpiece are grouped under the five headings, Cup , Rim, Throat, Backbore, Outer Shape and Stem

What the Parts of a Brass Mouthpiece do

The Mouthpiece Rim

The rim is the part of the mouthpiece which is in direct contact with your lips and is, in some ways, the easiest part to understand. Above all, it is important for the rim to feel comfortable on the lips and for you to be able to play for a reasonable time on the mouthpiece. In the PeakTone model, the rim may be varied in five different ways, by changing its thickness, width, rise, rim peak position and bite radius.

The Rim Thickness

The easiest one of these changes to deal with is the rim thickness or depth as this does not change the way the mouthpiece blows in any way. Changing the thickness or depth of the rim, changes the mouthpiece’s appearance only. When the Outer Shape Option of Turbo is selected, changes to the rim thickness are not apparent. To see how to change the rim’s thickness, please click here

The Rim Width

Unlike changes to a rim’s thicknes, changing its width does change the way the mouthpiece feels and performs for the player. As a beginner, you will need to have a reasonably-flat rim to provide a comfortable adequate support for the lips. Such a rim will also allow you to play for a reasonable length of time. However, there is a downside to a flat rim in that the area in contact with the lips, while offering support over a wide proportion of your lips, also provides friction over that area and stops them being able to change very rapidly. This, in turn will restrict the agility with which one can adjust to large pitch chabges. As you improve your embouchure and endurance, you may well find that you are able to handle a somewhat narrower mouthpiece rim. Your ideal shape might incorporate some raised, curved area over the rim’s upper surface.

 

When you change the rim’s width in the PeakTone model, more material is added to the outer edge of the rim.

In the PeakTone Model, the mouthpiece rim  width is also affected by the rim rise which creates a more-prominent central point on the rim’s top surface, please see Rim Rise , below.

To see how to change the rim’s thickness, please click here.

 

The shape and thickness of the mouthpiece’s rim is extremely important to how comfortable the mouthpiece feels, since it comes into direct contact with the player’s lips. The rim contour also has some effect on lip flexibility, attack clarity and pitch control.

 

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A thin or narrow rim with a rounded top offers plenty of control and flexibility over a wide range, but the relatively sharp contact area can quickly cause fatigue and even pain if too much pressure is used.

As with the other elements of a mouthpiece, finding a rim that has the right mix of comfort and performance may require some trial and error. Beginning players are probably better off choosing a rim of medium thickness, but a more experienced player should feel free to experiment with different rim shapes to see how they change the feel and response of the mouthpiece.

Rim Rise

The term ‘Rim Rise’ is used in the PeakTone Model to refer to the amount by which the central portion of the rim is raised or lowered from the flattened rim of any given mouthpiece rim surface.

 

Raising the rim, in effect, narrows the rim’s top surface, demonstrating how inter-related all the different parameters are. As the rim is narrowed in this way, it has the same effect as a reduction in the rim width setting discussed above, i.e., increased agility at the expence of endurance.  In the PeakTone model, as the top face of the rim is raised, so is the base of the cup, in order to maintain a consistent cup depth.

Rim Peak Position

The Rim Peak Position setting allows the central point of the rim’s peak to be placed anywhere from the cup edge to the outer edge of the rim. The setting is more noticeable when some rim rise is set and has no effect on a flat rim

Rim Bite Radius

The Rim Bite Radius setting controls the radius between the upper face of the rim and the inner wall of the cup. It is disabled when the Rim Peak Position is set to anything other than zero as moving

 

@@@@@@@@@@@@@@@@@@ ……..ADDED BIT 1

The Mouthpiece Cup

………..

The Cup Diameter

………….

The Cup Depth

…………….

 

 

 

The Cup Shoulder Angle

 

The Cup Conicity

 

xxxxxxxRim Bite Radius

 

@@@@@@@@@ End Block 1

Start Block 2 ?????????????????????????

The Mouthpiece Throat

………..

The Throat Diameter

………….

The Throat Radius

…………….

The Throat Depth

 

xxxxxxThe Cup Conicity

ccc

xxxxxxxRim Bite Radius

 

@@@@@@@@@ End Block 2

Start Block 3 ?????????????????????????

The Mouthpiece Backbore

………..

The Backbore Diameter

………….

The Backbore Barelling Width

…………….

 

 

 

The Backbore Barelling Depth

 

The Backbore Upper Profile Top

 

The Backbore Upper Profile Bottom

 

@@@@@@@@@ End Block 3

Start Block 4 ?????????????????????????

The Mouthpiece Stem

………..

The Lower Diameter

………….

The Receiver Depth

…………….

 

 

 

The receiver Diameter

 

The Stem Size

 

xxxxxxxRim Bite Radius

 

@@@@@@@@@ End Block 4

Start Block 5 ?????????????????????????

The Mouthpiece Outer Shape

………..

The Overall Length

………….

The Mouthpiece Style

…………….

 

 

 

The Mouthpiece ID

 

@@@@@@@@@ End Block 5