The Bell King Songdok the Great tolls magnificient sound that would be a great vehicle which brings all beings to the Sutras. Since 693, there was a magic flute, MANPASIKJUK, which was in existence in Shilla Dynasty that could lull all the evil-wawes, such an plaques, storms, Droughts, Famines and even Enemies. Thus, a sound tube, MANPASIKJUK, was erected in the crown of the Bell Songdok the Great so as to be effective to emit the nominal frequency tone whenever the Bell tolls for the national prosperity and welfare the People. Therefore, the Bell makers tried to fine the transmissibility condition through the sound tubr, several times during 34 years, However, it seems to be unfinished. Ever since, all of the korean Brahman Bell have the sound tubes of MANPASIKJUK, but none is performed their own functions. Here, one of the way to let the function of the sound tube of MANPASIKJUK out in the Bell Songdok the Great is proposed. There are two steps: the 1st is to elongate 18cm to the present length 77cm to fulfill the transmissibility condition for the nominal frequency of sound is emitted through the corrected sound tybe. 2nd step is to rise to 95% of the emission of the tone of nominal frequency, so that an exponential hem with the flare constant 2.8m-1, length 2.259m and the radius of the mouth 1.772m is to be extended to the corrected sound tube.