I can't find a control for vibrato depth or speed in Session Horns Pro
When you choose an articulation with vibrato, the vibrato is baked into the sample because you're hearing it as the performer played it.
When you choose a non-vibrato articulation, the mod-wheel controls a simulated vibrato. With the full version of Kontakt, you can go under the hood to the Modulation panel to alter the intensity and speed of that vibrato. (I don't have the Player version so I don't know if it can be done with that version.)
