  Quasi-lossless and asymmetric sound transports, which are exceedingly
desirable in various modern physical systems, are almost based on nonlinear or
angular-momentum biasing effects with extremely high power levels and complex
modulation schemes. A practical route for the steerable sound transport along
any arbitrary acoustic pathway, especially in a 3D acoustic network, could
revolutionize the sound power flow and the sound communication. Here, we design
an acoustic device consisting of a regular-tetrahedral cavity with four
cylindrical waveguides. A smaller regular-tetrahedral solid in this cavity is
eccentrically emplaced to break its spatial symmetry. The numerical and
experimental results show that the sound power flow can unimpededly transport
between two waveguides away from the eccentric solid within a wide frequency
range. Furthermore, in the vicinity of eigenmode, the sound waves from various
waveguides can transport to different waveguides, respectively along the
compressed and broadened pathways without mutually interference. Endowed with
these quasi-lossless and asymmetric transport characteristics, we construct a
3D acoustic network, in which the sound power flow can flexibly propagate along
arbitrary sound pathways defined by our acoustic devices with
eccentrically-emplaced regular-tetrahedral solids.
