The low E/F resonance mechanism solves the common intonation problem most Boehm clarinets have; the low E and F are very flat while the B and C are sharp.
We offer 3 different solutions which are acoustically identical but use different keys. In all of them, we add two resonance holes to the instrument. One will be located slightly above the C/F hole and one at the bell:
To play the low E or F in tune, you can either:
1. press an extra left-hand thumb key, located close to the thumb rest.
2. press a right-hand pinky key, located next to the C/F lever read more
3. let an automatic mechanism do it for you. read more
It is also possible to just get one of the keys installed.
One of the biggest advantages is probably the sound improvement for the low E. With the E-resonance hole it will have the same color and voice as the F.