Answer: The proper method of adjusting the breath knobs is as follows. The outer breath knob controls the amount of breath pressure necessary to start a note and "push" the note louder. The downside is there is a loss of control when this knob is adjusted too far counter-clockwise. Many players try to emulate the breath pressure of a sax, but I have found this is not optimum for EWI. I suggest turning the knob clockwise until the breath light comes on and the EWI emits sound on its own (minimum breath pressure). Then turn the knob backwards to the point that the light just goes off. Now try double-tonguing a passage while watching the light. The articulation should be clean on an internal patch that does not use the "multi" effect and the light should be going off and on in sync with the articulation. If it isn't adjust the knob a little further counter-clockwise.

The inner breath knob is to adjust the amount of breath necessary to open the filter. This makes the sound brighter as you blow harder. Adjust this knob by selecting a patch that has a good resonance filter type sound and blow into the EWI as hard as you can. Starting from the far right position (max-open filter to minimum breath) turn the knob counter-clockwise to the point that you hear the sound "dull" or loose resonance. Turn it back to the right slightly so that you are hearing maximum brightness. You have now set the breath to filter knob to open the filter wide open at maximum breath. This will yield the best expression.