A loudspeaker comprising: a loudspeaker enclosure; a plurality of high-frequency transducers disposed within the loudspeaker enclosure and aligned along a first plane; at least one lower frequency transducer disposed within the loudspeaker enclosure; and a waveguide mounted to the loudspeaker enclosure, the waveguide including: a plurality of entrances positioned at a first axial end of the waveguide, each entrance overlaying one of the high-frequency transducers; a mouth disposed at a second axial end of the waveguide opposite the plurality of entrances; a first pair of walls positioned opposite one another connecting each entrance to the mouth, each lower frequency transducer configured to be mounted to one of the first pair of walls; at least one integrator disposed between adjacent entrances and extending transversely between the first pair of walls, each integrator tapering towards the mouth to form a pointed edge along a direction of extension of the integrator, wherein each integrator has a pair of integrator surfaces angled with respect to one another, characterised in that each integrator surface includes a solid portion and a perforated portion, wherein the solid portion of each integrator surface is disposed adjacent the first pair of walls, and the perforated portion of each integrator surface is triangular-shaped with a base located along the center of the pointed edge; and at least one acoustic opening disposed in each of the first pair of walls between a pair of integrators, the at least one acoustic opening overlaying at least a portion of a radiating surface of the at least one lower frequency transducer. a loudspeaker enclosure; a plurality of high-frequency transducers disposed within the loudspeaker enclosure and aligned along a first plane; at least one lower frequency transducer disposed within the loudspeaker enclosure; and a waveguide mounted to the loudspeaker enclosure, the waveguide including: a plurality of entrances positioned at a first axial end of the waveguide, each entrance overlaying one of the high-frequency transducers; a mouth disposed at a second axial end of the waveguide opposite the plurality of entrances; a first pair of walls positioned opposite one another connecting each entrance to the mouth, each lower frequency transducer configured to be mounted to one of the first pair of walls; at least one integrator disposed between adjacent entrances and extending transversely between the first pair of walls, each integrator tapering towards the mouth to form a pointed edge along a direction of extension of the integrator, wherein each integrator has a pair of integrator surfaces angled with respect to one another, a plurality of entrances positioned at a first axial end of the waveguide, each entrance overlaying one of the high-frequency transducers; a mouth disposed at a second axial end of the waveguide opposite the plurality of entrances; a first pair of walls positioned opposite one another connecting each entrance to the mouth, each lower frequency transducer configured to be mounted to one of the first pair of walls; at least one integrator disposed between adjacent entrances and extending transversely between the first pair of walls, each integrator tapering towards the mouth to form a pointed edge along a direction of extension of the integrator, wherein each integrator has a pair of integrator surfaces angled with respect to one another, each integrator surface includes a solid portion and a perforated portion, wherein the solid portion of each integrator surface is disposed adjacent the first pair of walls, and the perforated portion of each integrator surface is triangular-shaped with a base located along the center of the pointed edge; and at least one acoustic opening disposed in each of the first pair of walls between a pair of integrators, the at least one acoustic opening overlaying at least a portion of a radiating surface of the at least one lower frequency transducer.