Abstract: The present acoustic system produces sounds over a broad range of frequencies, and includes an enclosure, a speaker acoustically connected to the enclosure, for generating, almost simultaneously, two sounds, a forward sound, and a rearward sound. It further includes a waveguide enclosed at least partly within the enclosure, and acoustically connected to the speaker, for defining an acoustic path along which the rearward sound travels. The waveguide includes a plurality of inner panels that are positioned inside the enclosure for optimizing the length of the travel path. The inner panels and the enclosure define a plurality of inner passageways having generally similar cross-sectional surface areas, and a plurality of inner openings, for causing a selective cancellation of sounds at predetermined frequencies, while preserving sounds at other frequencies.