A sound diffusion device comprising a high-frequency section with at least one high-frequency acoustic source, and a medium-frequency section (3, 4) with at least two medium-frequency acoustic sources, the acoustic sources (SHF, SMF) being vertically superimposed, characterized in that the medium-frequency section (3, 4) comprises a lower subsection arranged below the high-frequency section and comprising medium-frequency acoustic sources and an upper subsection arranged above the high-frequency section and comprising medium-frequency acoustic sources, where the medium-frequency acoustic sources (S MF) of the lower subsection are aligned with each other along a first vertical axis and/or the medium-frequency acoustic sources (S MF) of the upper subsection are aligned with each other along a second vertical axis, and in that the vertical directivity of the high-frequency section has an inclination (Θ HF), relative to the horizontal, substantially equal to the inclination (Θ MF) of the vertical directivity of the medium-frequency section (3, 4) relative to the horizontal, so that the overall vertical directivity of the device has a non-zero inclination (θ Dir) relative to the horizontal, the high-frequency section also has an asymmetrical vertical wavefront that is shaped by means of a vertical waveguide, integrating at least one high-frequency acoustic source, preferably all of the high-frequency acoustic sources, the acoustic center (C inf) of the lower subsection is set back relative to the acoustic center (C SUP) of the upper subsection, by a setback such that an axis, connecting the acoustic center (C inf) of the lower subsection to the acoustic center (C SUP) of the upper subsection, has an angle of misalignment (Θ D) relative to the vertical substantially equal to the inclination (Θ HF), and the wavefront is shaped mechanically, without electronic processing of the sound signals respectively sent to each of the high-frequency acoustic sources, by means of the waveguide which is a frame shaped specifically to form the desired wavefront and accommodating the acoustic sources by imposing a position and relative orientation on them. characterized in that the medium-frequency section (3, 4) comprises a lower subsection arranged below the high-frequency section and comprising medium-frequency acoustic sources and an upper subsection arranged above the high-frequency section and comprising medium-frequency acoustic sources, where the medium-frequency acoustic sources (S MF) of the lower subsection are aligned with each other along a first vertical axis and/or the medium-frequency acoustic sources (S MF) of the upper subsection are aligned with each other along a second vertical axis, and in that the vertical directivity of the high-frequency section has an inclination (Θ HF), relative to the horizontal, substantially equal to the inclination (Θ MF) of the vertical directivity of the medium-frequency section (3, 4) relative to the horizontal, so that the overall vertical directivity of the device has a non-zero inclination (θ Dir) relative to the horizontal, the high-frequency section also has an asymmetrical vertical wavefront that is shaped by means of a vertical waveguide, integrating at least one high-frequency acoustic source, preferably all of the high-frequency acoustic sources, the acoustic center (C inf) of the lower subsection is set back relative to the acoustic center (C SUP) of the upper subsection, by a setback such that an axis, connecting the acoustic center (C inf) of the lower subsection to the acoustic center (C SUP) of the upper subsection, has an angle of misalignment (Θ D) relative to the vertical substantially equal to the inclination (Θ HF), and the wavefront is shaped mechanically, without electronic processing of the sound signals respectively sent to each of the high-frequency acoustic sources, by means of the waveguide which is a frame shaped specifically to form the desired wavefront and accommodating the acoustic sources by imposing a position and relative orientation on them.