I'm curious if various instruments require that the player compensate in any way (in terms of technique, e.g., force used to bow, force used to blow, or embouchure alterations) when playing low vs. high notes.
On a violin or cello, say, if you use the identical bowing for a low-pitched note vs. a high-pitched note, will one note tend to sound louder than the other or will they both be the same volume? Are string players taught to, say, dig in a little more to make a low-pitched or high-pitched note project relative to the other?
On a clarinet or saxophone, if the exact same embouchure and breath pressure is used on a low-pitched note and a high-pitched note, will they sound at the same volume? (Also, will the upper note tend to be a bit flat or sharp?)
My experience, on the oboe, is that if the exact same breath pressure and embouchure are used on a low note versus a high note, the higher note will tend to be flat and to be the quieter of the two notes. I'm guessing that double reeds have special characteristics that contribute to this phenomena.
As I try and understand the situation better, I thought it might be useful to know if other instruments also require techniques to compensate for volume characteristics that are dependent upon the pitch of the note being played.
EDIT: I realized after posting that this question is more like a survey than a specific problem to be solved and thus it will be difficult to select a "best answer." I do appreciate the answers for specific instruments that arise from direct experience.