I got a full carved Strunal and the sound was like I expected but there is a weak (less Sustain) area between the F and the A on the E string. If I tune the A string down to the same notes it sounds also weak - so it sould be no problem of the fingerboard (string buzz) otherwise the same notes on ocatve higher don`t sound weak. I took the bass to a luthier and he adjusted the fingerboard, the soundpost, the bridge feets and put on new Spirocore. It`s a little bit better now but it`s still a big difference between the notes in this area and the rest. Does anyone have an idea what to do?