I'm not certain that Reinhardt actually wrote this anywhere, at least not to my recollection. He did make some comments about how different embouchure types would tend to have specific characteristics (i.e., Type IV players often had an easier upper register and brighter tone, IIIB players frequently a darker timbre, good flexibility), but he cautioned that these were just common tendencies, not specific features of the embouchure types. Either way, his main goal was to help each individual player understand how their anatomical features influenced how their embouchure functioned best in order to build on whatever strengths they already had and clean up any mechanical weaknesses. He certainly didn't mean that in order to get a strong upper register you should play with a protruded jaw position or for a dark sound and lots of volume you should play with a receded jaw position. Rather, he wanted each player to work with their physical characteristics and learn to play correctly for their proper embouchure type, not try to adopt characteristics that someone else happened to do. We all have different faces, we all have different embouchures.However most trumpet players use a receded jaw setting. Some have good range but seriously high screaming range is less common. Fortunately for most of us receded jaw players we can produce a "huge volume of tone in the upper register" quote from Donald Reinhardt.
There are elements of truth in your above quote, but also some misunderstandings. First, Reinhardt noticed the air stream direction's relationship to the ratio of upper to lower lip not by visualizing things from the outside, but by using transparent mouthpieces to view this. The link I posted on the last page has some photographs and video from a variety of sources that also show this. Secondly, Reinhardt also did view the player's horn angle/jaw position to be important and used them as some characteristics to define a player's embouchure type (as an aside, I think that perhaps he got too detailed in his classifications and unnecessarily confused people that didn't directly study from him or read his writing's carefully enough).The concept originated some 60 years ago (or thereabouts) from Donald Reinhardt and is just as inaccurate today as it was then. Doc defined UP as a lower lip dominant positioning ie more lower lip in the mouthpiece. And "Down" as more upper lip in the mouthpiece. However these categories only reference the visible indicators from outside the brass player. As such it is like judging the iceberg from what is visible above the water. Also by only Reinhardt's explanation your definition is also incorrect. Reinhardt created his categories based upon which lip was more in the mouthpiece NOT the horn angle or jaw positioning.
I could be wrong, so if you can find quotes please post them for us.
These are interesting thoughts, although I don't see any support that your hypothesis can be universally applied to all brass players. Can you explain in more detail how you arrived at these conclusions or is this more "arm chair" science based on what you feel works for your own chops?Dry lip chop settings are probably more of a common denominator in strong scream players than even the forward jaw positioning. Although the forward jaw is more conducive to dry lip playing as well. So its a double whammy help: The forward jaw tends to lend itself to dry lip play and the dry lip often allows easier high notes. That and the forward jaw positioning in and of itself is associated with high note proficiency.
That said, it does seem that playing with a dry embouchure can be useful for some players in the extreme upper register. Some players feel that their mouthpiece feels too slippery otherwise and simply prefer a dry embouchure. Other players state that things feel too "sticky" with dry lips. As was already noted earlier in this thread, many players change from one to another at different points in their career. As a personal anecdote, I went through a fairly radical embouchure change as a graduate student which required me to play with a dry embouchure to keep my placement consistent, but there were some drawbacks for me (I developed minor abrasions and sometimes found it hard to put the mouthpiece on my "sweet spot"). Gradually I changed to using a wet lower lip but keeping my upper lip dry (not uncommon for low placement/upstream embouchure players). Eventually I went all the way to a wet embouchure, which is how I currently play. Sometimes I practice playing dry again, as I feel it helps me practice certain things. Probably the reverse is true, that dry lip players may find occasionally practicing with a wet embouchure to be useful in some ways.
Everyone is different, so I would caution us to avoid making very specific recommendations about how you think everyone should play based on your own personal experiences. There's way too much personal baggage that influences the way we see things looking at other players, so it's probably best to qualify our statements when we muse about embouchure online.