  Neutron inelastic scattering investigations have been performed on the spin
tetrahedral system Cu_2Te_2O_5X_2 (X = Cl, Br). We report the observation of
magnetic excitations with a dispersive component in both compounds, associated
with the 3D incommensurate magnetic order that develops below $T^{Cl}_{N}$=18.2
K and $T^{Br}_{N}$=11.4 K. The excitation in Cu_2Te_2O_5Cl_2 softens as the
temperature approaches $T^{Cl}_{N}$, leaving diffuse quasi-elastic scattering
above the transition temperature. In the bromide, the excitations are present
well above $T^{Br}_{N}$, which might be attributed to the presence of a degree
of low dimensional correlations above $T^{Br}_{N}$ in this compound.
