We present the acoustic equivalent of supercoupling through subwavelength channels. Extraordinary matched transmission, energy squeezing and anomalous quasistatic tunnelling through narrow channels are obtained for acoustic waves by designing a 2D, density-near-zero metachannel. Transmission-line theory is used to describe this peculiar phenomenon, and full-wave simulations are presented to confirm the exotic transmission properties of the metamaterial. It is shown that acoustic waves may provide a unique possibility of squeezing energy in arbitrarily small channels in 3D, overcoming limitations usually arising in the electromagnetic case.