We compute the bulk sound speed along the Hugoniot using a new solid‐liquid two‐phase equation of state (EOS) for aluminum [Chisolm, Crockett, and Wallace, to appear in Phys. Rev. B] and compare with experimental sound speeds from various sources. The experiment extends from the crystal through the entire solid‐liquid two‐phase region. The EOS and data closely agree on where the Hugoniot passes through the two‐phase region, which corresponds to where aluminum melts. The bulk sound speed in the crystal region is consistent with the data, given the uncertainty in the experimental procedure. We also estimate shear moduli by using the experimental longitudinal sound speed data and the calculated bulk modulus. The shear modulus satisfies the approximationGS/BS=constant, within experimental error bars, throughout the crystal region on the Hugoniot. © 2004 American Institute of Physics