The chamber of the mouthpiece is the open area in the middle of the mouthpiece between the baffle and the bore. It is the area directly underneath the table, inside the mouthpiece. Generally there are considered to be three chamber sizes: large, medium, and small. However in actuality there are four: large, medium, small, and extra-small.
When the chamber (1B) has a larger diameter than the bore (1A) of the mouthpiece.
These mouthpieces were the very first mouthpieces made by Adolf Sax in 1841. The design was made famous by Otto link in the 1930s though with the Master Link model brass mouthpiece. These vintage mouthpieces are all True Large Chamber mouthpieces as they include significantly rounded inner side walls that extend all the way from the tip to the chamber. This makes the transition from the narrow tip rail into the large chamber smooth, and allows the air stream to spread producing a fat & warm sound. True Large Chamber mouthpiece lend themselves to a big fat bottom end and a more open and spread sound in general. This is the most common style among classic jazz musicians in tenor saxophone and among classical players throughout the whole saxophone family.
A vast majority of tenor saxophone musician’s in the 1950s and 1960s all played True Large Chamber mouthpiece. In the 1970s to present there have been many mouthpieces made that have a large chamber (where the chamber is larger than the bore) however, do not have significantly rounded inner side walls that extend all the way to the tip. These mouthpieces maintain many of the characteristics of a True Large Chamber, but not all. They tend to be more focused, and less fat sounding. This is because the air-stream, after entering the tip, does not spread width-wise in the mouthpiece as soon as a True Large Chamber mouthpiece does.
It is important to note that if a tenor mouthpiece were shrunk down to the size of an alto mouthpiece, the bore of the alto mouthpiece would be too small and would not fit onto the neck of the alto saxophone. Hence the bore must be larger to fit on the neck of an alto saxophone. This means the chamber (1B) of an alto mouthpiece looks smaller than a tenor when compared to the bore (1A). Both alto and tenor mouthpiece chambers (1B) are still larger than their bores (1A), however, it is not as large looking. For this reason many large chamber mouthpieces through history actually had larger chambers relative to their tenor counterparts, and why the medium chamber is generally more popular among alto players.
When the chamber (2B) has approximately the same diameter as the bore (2A) of the mouthpiece.
This chamber design was made famous by Meyer in the late 1940s. To this day the majority of alto mouthpieces all use a medium chamber. This chamber produces a full sound that is also centered with 'core' to it. They do not have the fat bottom end inherent to large chamber mouthpieces, but are still open and not thin sounding.
Medium chamber mouthpieces can have either concave inner side walls or flat inner side walls. The concave inner side-walls of a medium chamber are much shallower than those of a large chamber mouthpiece.
A good example of a medium chamber with rounded inner-side walls is the Meyer Bros. hard rubber mouthpiece from the 1950s shown here. A good example of a medium chamber with flat inner-side is the Brilhart Ebolin and Tonalin mouthpieces.
When the chamber (3B) has a smaller diameter than the bore (3A) of the mouthpiece.
A small chamber mouthpiece has a 'squeeze' in the interior shape of the chamber, such that the chamber is slightly smaller than the bore. This shape creates extra pop and aliveness in the sound, and a quicker more focused response. Think of putting your thumb over the end of a garden hose; the more you cover the hole the quicker the water comes out. A small chamber mouthpiece is like having your thumb further over the end of the hose. The airstream moves very quickly through a small chamber mouthpiece. Often a small chamber is used in conjunction with a high baffle to create a very focused and bright sound.
Small chamber mouthpieces usually have flat inner side walls as the side walls to transition the tip rails into the small chamber. Some of the old Meyer Bros. small chamber mouthpieces had a very small amount of concavity to the inner side walls. But, in general, small chamber mouthpieces do not.
Often the bottom end of the saxophone sounds thinner on small chamber mouthpieces.
When the chamber (4B) has an overtly smaller diameter than the bore (4A) of the mouthpiece, such that the chamber 'drops' down into the bore.
While looking in the shank through the bore of an extra-small chamber mouthpiece you will see a pronounced circle in the chamber. This is due to the chamber being so much smaller than the bore. The extra-small chamber is used for a great amount of focus and punch in the sound as the air-stream moves extremely quickly. Usually an extra-small chamber mouthpiece has a very high baffle and is used for rock and roll or R&B music. Examples of this chamber can be found in the Dukoff Super Power Chamber mouthpieces and Guardala King & Super King mouthpieces. Soprano saxophone mouthpieces are the exceptions to this rule. With soprano mouthpieces extra-small chambers are the standard of the industry for both a dark and bright sound. This is true for two reasons:
The opening of the neck on a soprano saxophone is so small relative to the bore of the mouthpiece that an extra-small chamber is simply narrowing the airstream to smoothly enter the neck of the soprano saxophone.
The sound inside the soprano mouthpiece is created more in the 'throat' of the mouthpiece than the chamber. The 'throat' of the soprano mouthpiece acts like the chamber would in alto, tenor, and baritone mouthpieces.
All extra-small chamber mouthpieces have flat inner side walls simply because there is just no room for anything else.