[dirty]

This is something I realized I've been a little unclear on for a while, but when we say a mouthpiece has a small/medium/large chamber, where along the path from the tip to the shank do we actually look to determine that?

For mouthpieces with pretty open designs all the way back, like Otto Links, it seems fairly straightforward, but designs with a more squeezed throat seem a little more up for debate.

I've usually seen the Selmer S80 described as having a small, square chamber. When I compare my bari S80 to my RPC 110B, both have a pronounced squeeze at the back of the floor before stepping into the bore. The RPC transitions to an oval throat where the Selmer just maintains the same straight line from the tip back. The RPC's throat is a little smaller than the Selmer, I think, though I honestly don't have the tools to really take the measurements.

The RPC drops off abruptly into the chamber as soon as it forms the oval shape. The Selmer, however, maintains that squeezed shape for a little longer, almost a cm, before also abruptly dropping off into the round bore. It's a little harder to get a good sense of exactly where the Selmer transitions to the bore because it's not translucent.

So if the Selmer is a small chamber (makes sense to me), what is the RPC? Obviously there's not a hard and fast rule, but generally speaking, where does the chamber start? Would that be considered a small chamber mouthpiece?

I know we can use the window as a reference, but different mouthpiece have different window lengths as well, so I'm not sure we can treat that as an absolute reference.

Looking at Theo Wanne's pages on both chamber sizes and Selmer mouthpieces, I don't really see this particular question addressed. The Selmer mouthpiece history page, for example, seems to refer to the short shank Soloists as having a "horseshoe chamber" but also describes "a small flat at the back of the floor (front of the chamber) in their molds" that gives them their horseshoe shape, which would seem to suggest that the chamber started from there and became round like the bore after that.

Here's what the RPC looks like:

Here's what the Selmer looks like. I don't know if this photo really shows how far back the square throat extends and I'm not sure if I know how to photograph that. This one is drilled for a pickup, so ignore the hole in the bore!

I really don't want to get into value judgments about large or small chambers. I learned to play on a Link STM, but I've played great mouthpieces that played in tune on all of my horns with a variety of chamber configurations and I just think everything needs to add up to something that works for the player. I just like learning about what makes things work and also how other people think about these things.

 

[dirty]

Maybe the better question is: to what extent are the throat and the chamber distinct from one another?

 

[Pete Thomas]

A “throat” is surely just a restriction that some lakers put in. It needn’t be there but if it is then it will probably affect the sound. I’m not a big fan of them and have had some success in removing them when researching and prototyping mouthpieces.

 

[1saxman]

In most cases the 'chamber' blends into the 'throat', so there's no clear-cut parting line. Then you have the 'Level Air' where there is no throat - there's the chamber formed by the long baffle which terminates as a 'ledge', and the rest of the piece is open to the rear. We called them 'shotgun' mouthpieces at the time. The 'chamber' is the area above the reed and is entirely within the opening of the 'window'. Its also the 'baffle' area, and where the baffle ends abruptly before the end of the window, there is a transition from that point to the throat. With a 'rollover' baffle, only the part closest to the tip can be called the chamber, with the rest of the baffle being a long transition to the throat. The throat may have features or it may not, but a 'ring' or 'square' feature is not a 'restriction' in the sense of holding back air flow - there's no aerodynamic quality to a mouthpiece design. What these various throat designs actually do I can't say, but I know that small changes to them reflect in how the piece plays/sounds.

 

[pontius]

The pieces in your photos seem to me to have a distinct, dramatic change where the throat meets the chamber. On a classic large chamber, concave sidewall type piece like Links and a lot of 20's 30's mouthpieces, it;s really impossible to say where the throat ends. If I had to say, I would say where the window ends.

 

[MojoBari]

Mouthpiece terms vary a bit in usage. I like Theo's definition of a medium chamber being the same diameter as the bore for the neck cork. But I mostly refer to this as the throat area. The chamber is the region of the throat and the lower baffle away from the tip. It is useful if you consider chamber short for chamber volume.

https://theowanne.com/knowledge/chamber-sizes/

 

[turf3]

I am not a mouthpiece professional by any means but I think of "chamber" as being the whole volume from the facing down to the end of the neck when in playing position, and the "throat" as a subregion of the chamber, basically that area where the baffle transitions into the bore.

 

[Benjamin Allen]

I am not a mouthpiece professional by any means but I think of "chamber" as being the whole volume from the facing down to the end of the neck when in playing position, and the "throat" as a subregion of the chamber, basically that area where the baffle transitions into the bore.

I agree with Mojo in that terms vary, but your statement is generally the way I describe a piece to those who have to suffer through my discussions. Internally, I tend to think about the volume of a piece, excluding the shank/bore contained on the neck, along with the baffle and sidewalls shape and design as valuable information when discussing a mouthpiece. I perceive the chamber as preceding the bore, and the shape of the walls as being the subregion you caption as the throat region. I've heard it explained differently, and don't object to varying explanations.