their associated stand in various dispositions and inclinations two typical examples of such dispositions and inclinations are shown in fig1 and 2 in the disposition shown in fig1 two drums 1 and 2 are mounted to a stand 3 which is supported substantially upright on the floor by adjustable legs 4 via an upper mounting assembly 10 and an adjustable tilter device 6 the latter connecting the upper mounting assembly atop the stand 3 in the illustrated disposition the axial directions of the drums 1 and 2 i e the directions substantially perpendicular to their drum heads 1a and 2a are almost parallel to the axial direction of the stand 3 in other words the axial directions of the drums 1 and 2 are vertical this disposition of the drums 1 and 2 will hereinafter be referred to as 34 the parallel mounting 34 of the drums in this specification in the disposition shown in fig2 the drums 1 and 2 are mounted to the stand 3 in such an arrangement that the axial directions of the drums 1 and 2 are inclined with respect to the axial direction of the stand 3 in other words the axial directions of the drums 1 and 2 are oblique to the vertical direction this disposition will hereinafter be referred to as 34 the inclined mounting 34.