Abstract: A compact loudspeaker system adapted for the reproduction of sound at minimum distortion. Two small diameter direct radiator loudspeakers and a matching crossover network are mounted in a common enclosure having a short non-folded transmission line completely filled with randomly oriented non-woven fibers, said fibers having a single installed density within range of 12 to 30 ounces per cubic foot. The first of these speakers, a bass/mid range unit is acoustically coupled to one end of the fiber filled transmission line by exposing the speaker radiator rear surface to the line while the second speaker, a high frequency unit, is acoustically isolated from the transmission line by encapsulating the speaker radiator rear surface in a housing integral with the second speaker. A port, located at the end of the transmission line, acoustically couples said line to the atmosphere.