Portable computer structures are provided. The portable computer structures may include speaker grill structures. A speaker grill structure may be formed by creating an array of small holes (perforations) in a portable computer housing structure such as a planar housing wall. A speaker may be mounted adjacent to the array of holes. The planar housing wall may be formed in a block of milled aluminum and may have a thickness of less than 1 mm. The speaker holes may have with small diameters without overly attenuating sound from a speaker.